[PATCH 5.10/5.15] io_uring: fix registered files leak

[PATCH 5.10/5.15] io_uring: fix registered files leak

[Fedor Pchelkin]

No upstream commit exists for this patch.

Backport of commit 705318a99a13 ("io_uring/af_unix: disable sending
io_uring over sockets") introduced registered files leaks in 5.10/5.15
stable branches when CONFIG_UNIX is enabled.

The 5.10/5.15 backports removed io_sqe_file_register() calls from
io_install_fixed_file() and __io_sqe_files_update() so that newly added
files aren't passed to UNIX-related skbs and thus can't be put during
unregistering process. Skbs in the ring socket receive queue are released
but there is no skb having reference to the newly updated file.

In other words, when CONFIG_UNIX is enabled there would be no fput() when
files are unregistered for the corresponding fget() from
io_install_fixed_file() and __io_sqe_files_update().

Drop several code paths related to SCM_RIGHTS as a partial change from
commit 6e5e6d274956 ("io_uring: drop any code related to SCM_RIGHTS").
This code is useless in stable branches now, too, but is causing leaks in
5.10/5.15.

As stated above, the affected code was removed in upstream by
commit 6e5e6d274956 ("io_uring: drop any code related to SCM_RIGHTS").

Fresher stables from 6.1 have io_file_need_scm() stub function which
usage is effectively equivalent to dropping most of SCM-related code.

5.4 seems not to be affected with this problem since SCM-related
functions have been dropped there by the backport-patch.

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

Fixes: 705318a99a13 ("io_uring/af_unix: disable sending io_uring over sockets")
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
---
I feel io_uring-SCM related code should be dropped entirely from the
stable branches as the backports already differ greatly between versions
and some parts are still kept, some have been dropped in a non-consistent
order. Though this might contradict with stable kernel rules or be
inappropriate for some other reason.

 io_uring/io_uring.c | 177 --------------------------------------------
 1 file changed, 177 deletions(-)

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 936abc6ee450..6ad078a3bf30 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -62,7 +62,6 @@
 #include <linux/net.h>
 #include <net/sock.h>
 #include <net/af_unix.h>
-#include <net/scm.h>
 #include <linux/anon_inodes.h>
 #include <linux/sched/mm.h>
 #include <linux/uaccess.h>
@@ -7989,15 +7988,6 @@ static void io_free_file_tables(struct io_file_table *table)
 
 static void __io_sqe_files_unregister(struct io_ring_ctx *ctx)
 {
-#if defined(CONFIG_UNIX)
-	if (ctx->ring_sock) {
-		struct sock *sock = ctx->ring_sock->sk;
-		struct sk_buff *skb;
-
-		while ((skb = skb_dequeue(&sock->sk_receive_queue)) != NULL)
-			kfree_skb(skb);
-	}
-#else
 	int i;
 
 	for (i = 0; i < ctx->nr_user_files; i++) {
@@ -8007,7 +7997,6 @@ static void __io_sqe_files_unregister(struct io_ring_ctx *ctx)
 		if (file)
 			fput(file);
 	}
-#endif
 	io_free_file_tables(&ctx->file_table);
 	io_rsrc_data_free(ctx->file_data);
 	ctx->file_data = NULL;
@@ -8159,170 +8148,10 @@ static struct io_sq_data *io_get_sq_data(struct io_uring_params *p,
 	return sqd;
 }
 
-#if defined(CONFIG_UNIX)
-/*
- * Ensure the UNIX gc is aware of our file set, so we are certain that
- * the io_uring can be safely unregistered on process exit, even if we have
- * loops in the file referencing.
- */
-static int __io_sqe_files_scm(struct io_ring_ctx *ctx, int nr, int offset)
-{
-	struct sock *sk = ctx->ring_sock->sk;
-	struct scm_fp_list *fpl;
-	struct sk_buff *skb;
-	int i, nr_files;
-
-	fpl = kzalloc(sizeof(*fpl), GFP_KERNEL);
-	if (!fpl)
-		return -ENOMEM;
-
-	skb = alloc_skb(0, GFP_KERNEL);
-	if (!skb) {
-		kfree(fpl);
-		return -ENOMEM;
-	}
-
-	skb->sk = sk;
-	skb->scm_io_uring = 1;
-
-	nr_files = 0;
-	fpl->user = get_uid(current_user());
-	for (i = 0; i < nr; i++) {
-		struct file *file = io_file_from_index(ctx, i + offset);
-
-		if (!file)
-			continue;
-		fpl->fp[nr_files] = get_file(file);
-		unix_inflight(fpl->user, fpl->fp[nr_files]);
-		nr_files++;
-	}
-
-	if (nr_files) {
-		fpl->max = SCM_MAX_FD;
-		fpl->count = nr_files;
-		UNIXCB(skb).fp = fpl;
-		skb->destructor = unix_destruct_scm;
-		refcount_add(skb->truesize, &sk->sk_wmem_alloc);
-		skb_queue_head(&sk->sk_receive_queue, skb);
-
-		for (i = 0; i < nr; i++) {
-			struct file *file = io_file_from_index(ctx, i + offset);
-
-			if (file)
-				fput(file);
-		}
-	} else {
-		kfree_skb(skb);
-		free_uid(fpl->user);
-		kfree(fpl);
-	}
-
-	return 0;
-}
-
-/*
- * If UNIX sockets are enabled, fd passing can cause a reference cycle which
- * causes regular reference counting to break down. We rely on the UNIX
- * garbage collection to take care of this problem for us.
- */
-static int io_sqe_files_scm(struct io_ring_ctx *ctx)
-{
-	unsigned left, total;
-	int ret = 0;
-
-	total = 0;
-	left = ctx->nr_user_files;
-	while (left) {
-		unsigned this_files = min_t(unsigned, left, SCM_MAX_FD);
-
-		ret = __io_sqe_files_scm(ctx, this_files, total);
-		if (ret)
-			break;
-		left -= this_files;
-		total += this_files;
-	}
-
-	if (!ret)
-		return 0;
-
-	while (total < ctx->nr_user_files) {
-		struct file *file = io_file_from_index(ctx, total);
-
-		if (file)
-			fput(file);
-		total++;
-	}
-
-	return ret;
-}
-#else
-static int io_sqe_files_scm(struct io_ring_ctx *ctx)
-{
-	return 0;
-}
-#endif
-
 static void io_rsrc_file_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc)
 {
 	struct file *file = prsrc->file;
-#if defined(CONFIG_UNIX)
-	struct sock *sock = ctx->ring_sock->sk;
-	struct sk_buff_head list, *head = &sock->sk_receive_queue;
-	struct sk_buff *skb;
-	int i;
-
-	__skb_queue_head_init(&list);
-
-	/*
-	 * Find the skb that holds this file in its SCM_RIGHTS. When found,
-	 * remove this entry and rearrange the file array.
-	 */
-	skb = skb_dequeue(head);
-	while (skb) {
-		struct scm_fp_list *fp;
-
-		fp = UNIXCB(skb).fp;
-		for (i = 0; i < fp->count; i++) {
-			int left;
-
-			if (fp->fp[i] != file)
-				continue;
-
-			unix_notinflight(fp->user, fp->fp[i]);
-			left = fp->count - 1 - i;
-			if (left) {
-				memmove(&fp->fp[i], &fp->fp[i + 1],
-						left * sizeof(struct file *));
-			}
-			fp->count--;
-			if (!fp->count) {
-				kfree_skb(skb);
-				skb = NULL;
-			} else {
-				__skb_queue_tail(&list, skb);
-			}
-			fput(file);
-			file = NULL;
-			break;
-		}
-
-		if (!file)
-			break;
-
-		__skb_queue_tail(&list, skb);
-
-		skb = skb_dequeue(head);
-	}
-
-	if (skb_peek(&list)) {
-		spin_lock_irq(&head->lock);
-		while ((skb = __skb_dequeue(&list)) != NULL)
-			__skb_queue_tail(head, skb);
-		spin_unlock_irq(&head->lock);
-	}
-#else
 	fput(file);
-#endif
 }
 
 static void __io_rsrc_put_work(struct io_rsrc_node *ref_node)
@@ -8433,12 +8262,6 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
 		io_fixed_file_set(io_fixed_file_slot(&ctx->file_table, i), file);
 	}
 
-	ret = io_sqe_files_scm(ctx);
-	if (ret) {
-		__io_sqe_files_unregister(ctx);
-		return ret;
-	}
-
 	io_rsrc_node_switch(ctx, NULL);
 	return ret;
 out_fput:
-- 
2.44.0

Re: [PATCH 5.10/5.15] io_uring: fix registered files leak

[Jens Axboe]

On 3/12/24 8:23 AM, Fedor Pchelkin wrote:
> No upstream commit exists for this patch.
> 
> Backport of commit 705318a99a13 ("io_uring/af_unix: disable sending
> io_uring over sockets") introduced registered files leaks in 5.10/5.15
> stable branches when CONFIG_UNIX is enabled.
> 
> The 5.10/5.15 backports removed io_sqe_file_register() calls from
> io_install_fixed_file() and __io_sqe_files_update() so that newly added
> files aren't passed to UNIX-related skbs and thus can't be put during
> unregistering process. Skbs in the ring socket receive queue are released
> but there is no skb having reference to the newly updated file.
> 
> In other words, when CONFIG_UNIX is enabled there would be no fput() when
> files are unregistered for the corresponding fget() from
> io_install_fixed_file() and __io_sqe_files_update().
> 
> Drop several code paths related to SCM_RIGHTS as a partial change from
> commit 6e5e6d274956 ("io_uring: drop any code related to SCM_RIGHTS").
> This code is useless in stable branches now, too, but is causing leaks in
> 5.10/5.15.
> 
> As stated above, the affected code was removed in upstream by
> commit 6e5e6d274956 ("io_uring: drop any code related to SCM_RIGHTS").
> 
> Fresher stables from 6.1 have io_file_need_scm() stub function which
> usage is effectively equivalent to dropping most of SCM-related code.
> 
> 5.4 seems not to be affected with this problem since SCM-related
> functions have been dropped there by the backport-patch.
> 
> Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
> 
> Fixes: 705318a99a13 ("io_uring/af_unix: disable sending io_uring over sockets")
> Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
> ---
> I feel io_uring-SCM related code should be dropped entirely from the
> stable branches as the backports already differ greatly between versions
> and some parts are still kept, some have been dropped in a non-consistent
> order. Though this might contradict with stable kernel rules or be
> inappropriate for some other reason.

Looks fine to me, and I agree, it makes much more sense to drop it all
from 5.10/5.15-stable as well to keep them in sync with upstream. And I
think this is fine for stable, dropping code is always a good thing.

-- 
Jens Axboe

Re: [PATCH 5.10/5.15] io_uring: fix registered files leak

[Fedor Pchelkin]

On 24/03/12 08:34AM, Jens Axboe wrote:
> On 3/12/24 8:23 AM, Fedor Pchelkin wrote:

[...]

> > I feel io_uring-SCM related code should be dropped entirely from the
> > stable branches as the backports already differ greatly between versions
> > and some parts are still kept, some have been dropped in a non-consistent
> > order. Though this might contradict with stable kernel rules or be
> > inappropriate for some other reason.
> 
> Looks fine to me, and I agree, it makes much more sense to drop it all
> from 5.10/5.15-stable as well to keep them in sync with upstream. And I
> think this is fine for stable, dropping code is always a good thing.
> 

Alright, got it. So that would require dropping it from all of the
supported 5.4, 6.1, 6.6, 6.7, too.

Would it be okay if I'll send this as a series?

--
Fedor

Re: [PATCH 5.10/5.15] io_uring: fix registered files leak

[Jens Axboe]

On 3/12/24 9:14 AM, Fedor Pchelkin wrote:
> On 24/03/12 08:34AM, Jens Axboe wrote:
>> On 3/12/24 8:23 AM, Fedor Pchelkin wrote:
> 
> [...]
> 
>>> I feel io_uring-SCM related code should be dropped entirely from the
>>> stable branches as the backports already differ greatly between versions
>>> and some parts are still kept, some have been dropped in a non-consistent
>>> order. Though this might contradict with stable kernel rules or be
>>> inappropriate for some other reason.
>>
>> Looks fine to me, and I agree, it makes much more sense to drop it all
>> from 5.10/5.15-stable as well to keep them in sync with upstream. And I
>> think this is fine for stable, dropping code is always a good thing.
>>
> 
> Alright, got it. So that would require dropping it from all of the
> supported 5.4, 6.1, 6.6, 6.7, too.
> 
> Would it be okay if I'll send this as a series?

Yeah I think so, keeping the code more in sync is always a good thing
when it comes to stable. Just make sure you mark the backport commits
with the appropriate upstream shas. Thanks!

-- 
Jens Axboe

Re: [PATCH 5.10/5.15] io_uring: fix registered files leak

[Jens Axboe]

On 3/12/24 9:21 AM, Jens Axboe wrote:
> On 3/12/24 9:14 AM, Fedor Pchelkin wrote:
>> On 24/03/12 08:34AM, Jens Axboe wrote:
>>> On 3/12/24 8:23 AM, Fedor Pchelkin wrote:
>>
>> [...]
>>
>>>> I feel io_uring-SCM related code should be dropped entirely from the
>>>> stable branches as the backports already differ greatly between versions
>>>> and some parts are still kept, some have been dropped in a non-consistent
>>>> order. Though this might contradict with stable kernel rules or be
>>>> inappropriate for some other reason.
>>>
>>> Looks fine to me, and I agree, it makes much more sense to drop it all
>>> from 5.10/5.15-stable as well to keep them in sync with upstream. And I
>>> think this is fine for stable, dropping code is always a good thing.
>>>
>>
>> Alright, got it. So that would require dropping it from all of the
>> supported 5.4, 6.1, 6.6, 6.7, too.
>>
>> Would it be okay if I'll send this as a series?
> 
> Yeah I think so, keeping the code more in sync is always a good thing
> when it comes to stable. Just make sure you mark the backport commits
> with the appropriate upstream shas. Thanks!

I'll just do these backports myself, thanks for bringing it up.

-- 
Jens Axboe

Re: [PATCH 5.10/5.15] io_uring: fix registered files leak

[Fedor Pchelkin]

On 24/03/12 11:54AM, Jens Axboe wrote:
> On 3/12/24 9:21 AM, Jens Axboe wrote:
> > On 3/12/24 9:14 AM, Fedor Pchelkin wrote:
> >> On 24/03/12 08:34AM, Jens Axboe wrote:
> >>> On 3/12/24 8:23 AM, Fedor Pchelkin wrote:
> >>
> >> [...]
> >>
> >>>> I feel io_uring-SCM related code should be dropped entirely from the
> >>>> stable branches as the backports already differ greatly between versions
> >>>> and some parts are still kept, some have been dropped in a non-consistent
> >>>> order. Though this might contradict with stable kernel rules or be
> >>>> inappropriate for some other reason.
> >>>
> >>> Looks fine to me, and I agree, it makes much more sense to drop it all
> >>> from 5.10/5.15-stable as well to keep them in sync with upstream. And I
> >>> think this is fine for stable, dropping code is always a good thing.
> >>>
> >>
> >> Alright, got it. So that would require dropping it from all of the
> >> supported 5.4, 6.1, 6.6, 6.7, too.
> >>
> >> Would it be okay if I'll send this as a series?
> > 
> > Yeah I think so, keeping the code more in sync is always a good thing
> > when it comes to stable. Just make sure you mark the backport commits
> > with the appropriate upstream shas. Thanks!
> 
> I'll just do these backports myself, thanks for bringing it up.

Great, thanks!

--
Fedor

Re: [PATCH 5.10/5.15] io_uring: fix registered files leak

[Jens Axboe]

[-- Attachment #1: Type: text/plain, Size: 375 bytes --]

Hi,

OK, here they are. Two patches attached for every stable kernel, that
gets rid of the remnants of the SCM related code:

5.4
5.10 and 5.15 (same patches)
6.1
6.6
6.7

Would appreciate if Fedor and Pavel could give them a once over, but I
think they are all fine. It's just deleting the code...

Barring no complaints, Greg can you queue them up? Thanks!

-- 
Jens Axboe

[-- Attachment #2: 5.4-0001-io_uring-unix-drop-usage-of-io_uring-socket.patch --]
[-- Type: text/x-patch, Size: 3202 bytes --]

From 53e9e0ced4e4146ff57635c8ee65a57f3ed33fe3 Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@kernel.dk>
Date: Wed, 13 Mar 2024 18:33:48 -0600
Subject: [PATCH 1/2] io_uring/unix: drop usage of io_uring socket

Commit a4104821ad651d8a0b374f0b2474c345bbb42f82 upstream.

Since we no longer allow sending io_uring fds over SCM_RIGHTS, move to
using io_is_uring_fops() to detect whether this is a io_uring fd or not.
With that done, kill off io_uring_get_socket() as nobody calls it
anymore.

This is in preparation to yanking out the rest of the core related to
unix gc with io_uring.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 fs/io_uring.c      | 18 +++++-------------
 include/linux/fs.h |  6 +++---
 net/core/scm.c     |  2 +-
 net/unix/scm.c     |  4 +---
 4 files changed, 10 insertions(+), 20 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 9de8961763b0..cd1858cc6320 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -381,19 +381,6 @@ static struct kmem_cache *req_cachep;
 
 static const struct file_operations io_uring_fops;
 
-struct sock *io_uring_get_socket(struct file *file)
-{
-#if defined(CONFIG_UNIX)
-	if (file->f_op == &io_uring_fops) {
-		struct io_ring_ctx *ctx = file->private_data;
-
-		return ctx->ring_sock->sk;
-	}
-#endif
-	return NULL;
-}
-EXPORT_SYMBOL(io_uring_get_socket);
-
 static void io_ring_ctx_ref_free(struct percpu_ref *ref)
 {
 	struct io_ring_ctx *ctx = container_of(ref, struct io_ring_ctx, refs);
@@ -3794,6 +3781,11 @@ static const struct file_operations io_uring_fops = {
 	.fasync		= io_uring_fasync,
 };
 
+bool io_is_uring_fops(struct file *file)
+{
+	return file->f_op == &io_uring_fops;
+}
+
 static int io_allocate_scq_urings(struct io_ring_ctx *ctx,
 				  struct io_uring_params *p)
 {
diff --git a/include/linux/fs.h b/include/linux/fs.h
index e009b52ab6b0..272f261894b1 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -3614,11 +3614,11 @@ extern int generic_fadvise(struct file *file, loff_t offset, loff_t len,
 			   int advice);
 
 #if defined(CONFIG_IO_URING)
-extern struct sock *io_uring_get_socket(struct file *file);
+bool io_is_uring_fops(struct file *file);
 #else
-static inline struct sock *io_uring_get_socket(struct file *file)
+static inline bool io_is_uring_fops(struct file *file)
 {
-	return NULL;
+	return false;
 }
 #endif
 
diff --git a/net/core/scm.c b/net/core/scm.c
index 5525c14f33f1..a442bf63cd48 100644
--- a/net/core/scm.c
+++ b/net/core/scm.c
@@ -105,7 +105,7 @@ static int scm_fp_copy(struct cmsghdr *cmsg, struct scm_fp_list **fplp)
 		if (fd < 0 || !(file = fget_raw(fd)))
 			return -EBADF;
 		/* don't allow io_uring files */
-		if (io_uring_get_socket(file)) {
+		if (io_is_uring_fops(file)) {
 			fput(file);
 			return -EINVAL;
 		}
diff --git a/net/unix/scm.c b/net/unix/scm.c
index e881a6e78af5..51b623de3be5 100644
--- a/net/unix/scm.c
+++ b/net/unix/scm.c
@@ -33,10 +33,8 @@ struct sock *unix_get_socket(struct file *filp)
 		/* PF_UNIX ? */
 		if (s && sock->ops && sock->ops->family == PF_UNIX)
 			u_sock = s;
-	} else {
-		/* Could be an io_uring instance */
-		u_sock = io_uring_get_socket(filp);
 	}
+
 	return u_sock;
 }
 EXPORT_SYMBOL(unix_get_socket);
-- 
2.43.0


[-- Attachment #3: 5.4-0002-io_uring-drop-any-code-related-to-SCM_RIGHTS.patch --]
[-- Type: text/x-patch, Size: 3287 bytes --]

From a21d37be81f8dc59d4cda4aac37312f0774e4b71 Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@kernel.dk>
Date: Wed, 13 Mar 2024 18:36:18 -0600
Subject: [PATCH 2/2] io_uring: drop any code related to SCM_RIGHTS

Commit 6e5e6d274956305f1fc0340522b38f5f5be74bdb upstream.

This is dead code after we dropped support for passing io_uring fds
over SCM_RIGHTS, get rid of it.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 fs/io_uring.c | 47 +++--------------------------------------------
 1 file changed, 3 insertions(+), 44 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index cd1858cc6320..2c793e4ccf09 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -63,7 +63,6 @@
 #include <linux/net.h>
 #include <net/sock.h>
 #include <net/af_unix.h>
-#include <net/scm.h>
 #include <linux/anon_inodes.h>
 #include <linux/sched/mm.h>
 #include <linux/uaccess.h>
@@ -264,10 +263,6 @@ struct io_ring_ctx {
 
 	struct async_list	pending_async[2];
 
-#if defined(CONFIG_UNIX)
-	struct socket		*ring_sock;
-#endif
-
 	struct list_head	task_list;
 	spinlock_t		task_lock;
 };
@@ -3067,20 +3062,10 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
 
 static void __io_sqe_files_unregister(struct io_ring_ctx *ctx)
 {
-#if defined(CONFIG_UNIX)
-	if (ctx->ring_sock) {
-		struct sock *sock = ctx->ring_sock->sk;
-		struct sk_buff *skb;
-
-		while ((skb = skb_dequeue(&sock->sk_receive_queue)) != NULL)
-			kfree_skb(skb);
-	}
-#else
 	int i;
 
 	for (i = 0; i < ctx->nr_user_files; i++)
 		fput(ctx->user_files[i]);
-#endif
 }
 
 static int io_sqe_files_unregister(struct io_ring_ctx *ctx)
@@ -3575,13 +3560,6 @@ static void io_ring_ctx_free(struct io_ring_ctx *ctx)
 	io_sqe_files_unregister(ctx);
 	io_eventfd_unregister(ctx);
 
-#if defined(CONFIG_UNIX)
-	if (ctx->ring_sock) {
-		ctx->ring_sock->file = NULL; /* so that iput() is called */
-		sock_release(ctx->ring_sock);
-	}
-#endif
-
 	io_mem_free(ctx->rings);
 	io_mem_free(ctx->sq_sqes);
 
@@ -3833,45 +3811,26 @@ static int io_allocate_scq_urings(struct io_ring_ctx *ctx,
 /*
  * Allocate an anonymous fd, this is what constitutes the application
  * visible backing of an io_uring instance. The application mmaps this
- * fd to gain access to the SQ/CQ ring details. If UNIX sockets are enabled,
- * we have to tie this fd to a socket for file garbage collection purposes.
+ * fd to gain access to the SQ/CQ ring details.
  */
 static int io_uring_get_fd(struct io_ring_ctx *ctx)
 {
 	struct file *file;
 	int ret;
 
-#if defined(CONFIG_UNIX)
-	ret = sock_create_kern(&init_net, PF_UNIX, SOCK_RAW, IPPROTO_IP,
-				&ctx->ring_sock);
-	if (ret)
-		return ret;
-#endif
-
 	ret = get_unused_fd_flags(O_RDWR | O_CLOEXEC);
 	if (ret < 0)
-		goto err;
+		return ret;
 
 	file = anon_inode_getfile("[io_uring]", &io_uring_fops, ctx,
 					O_RDWR | O_CLOEXEC);
 	if (IS_ERR(file)) {
 		put_unused_fd(ret);
-		ret = PTR_ERR(file);
-		goto err;
+		return PTR_ERR(file);
 	}
 
-#if defined(CONFIG_UNIX)
-	ctx->ring_sock->file = file;
-	ctx->ring_sock->sk->sk_user_data = ctx;
-#endif
 	fd_install(ret, file);
 	return ret;
-err:
-#if defined(CONFIG_UNIX)
-	sock_release(ctx->ring_sock);
-	ctx->ring_sock = NULL;
-#endif
-	return ret;
 }
 
 static int io_uring_create(unsigned entries, struct io_uring_params *p)
-- 
2.43.0


[-- Attachment #4: 6.7-0001-io_uring-unix-drop-usage-of-io_uring-socket.patch --]
[-- Type: text/x-patch, Size: 4036 bytes --]

From 25b0645afe6459437da6cff71546984597f209da Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@kernel.dk>
Date: Tue, 19 Dec 2023 12:30:43 -0700
Subject: [PATCH 1/2] io_uring/unix: drop usage of io_uring socket

Commit a4104821ad651d8a0b374f0b2474c345bbb42f82 upstream.

Since we no longer allow sending io_uring fds over SCM_RIGHTS, move to
using io_is_uring_fops() to detect whether this is a io_uring fd or not.
With that done, kill off io_uring_get_socket() as nobody calls it
anymore.

This is in preparation to yanking out the rest of the core related to
unix gc with io_uring.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 include/linux/io_uring.h |  9 +++++----
 io_uring/io_uring.c      | 13 -------------
 io_uring/io_uring.h      |  1 -
 net/core/scm.c           |  2 +-
 net/unix/scm.c           |  4 +---
 5 files changed, 7 insertions(+), 22 deletions(-)

diff --git a/include/linux/io_uring.h b/include/linux/io_uring.h
index aefb73eeeebf..b3a32687f514 100644
--- a/include/linux/io_uring.h
+++ b/include/linux/io_uring.h
@@ -93,6 +93,7 @@ int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags);
 void io_uring_cmd_mark_cancelable(struct io_uring_cmd *cmd,
 		unsigned int issue_flags);
 struct task_struct *io_uring_cmd_get_task(struct io_uring_cmd *cmd);
+bool io_is_uring_fops(struct file *file);
 #else
 static inline int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
 			      struct iov_iter *iter, void *ioucmd)
@@ -111,10 +112,6 @@ static inline void io_uring_cmd_do_in_task_lazy(struct io_uring_cmd *ioucmd,
 			void (*task_work_cb)(struct io_uring_cmd *, unsigned))
 {
 }
-static inline struct sock *io_uring_get_socket(struct file *file)
-{
-	return NULL;
-}
 static inline void io_uring_task_cancel(void)
 {
 }
@@ -141,6 +138,10 @@ static inline struct task_struct *io_uring_cmd_get_task(struct io_uring_cmd *cmd
 {
 	return NULL;
 }
+static inline bool io_is_uring_fops(struct file *file)
+{
+	return false;
+}
 #endif
 
 #endif
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 59f5791c90c3..06bd8795a87d 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -177,19 +177,6 @@ static struct ctl_table kernel_io_uring_disabled_table[] = {
 };
 #endif
 
-struct sock *io_uring_get_socket(struct file *file)
-{
-#if defined(CONFIG_UNIX)
-	if (io_is_uring_fops(file)) {
-		struct io_ring_ctx *ctx = file->private_data;
-
-		return ctx->ring_sock->sk;
-	}
-#endif
-	return NULL;
-}
-EXPORT_SYMBOL(io_uring_get_socket);
-
 static inline void io_submit_flush_completions(struct io_ring_ctx *ctx)
 {
 	if (!wq_list_empty(&ctx->submit_state.compl_reqs) ||
diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h
index c9992cd7f138..0d66a7058dbe 100644
--- a/io_uring/io_uring.h
+++ b/io_uring/io_uring.h
@@ -61,7 +61,6 @@ struct file *io_file_get_fixed(struct io_kiocb *req, int fd,
 			       unsigned issue_flags);
 
 void __io_req_task_work_add(struct io_kiocb *req, unsigned flags);
-bool io_is_uring_fops(struct file *file);
 bool io_alloc_async_data(struct io_kiocb *req);
 void io_req_task_queue(struct io_kiocb *req);
 void io_queue_iowq(struct io_kiocb *req, struct io_tw_state *ts_dont_use);
diff --git a/net/core/scm.c b/net/core/scm.c
index 7dc47c17d863..737917c7ac62 100644
--- a/net/core/scm.c
+++ b/net/core/scm.c
@@ -105,7 +105,7 @@ static int scm_fp_copy(struct cmsghdr *cmsg, struct scm_fp_list **fplp)
 		if (fd < 0 || !(file = fget_raw(fd)))
 			return -EBADF;
 		/* don't allow io_uring files */
-		if (io_uring_get_socket(file)) {
+		if (io_is_uring_fops(file)) {
 			fput(file);
 			return -EINVAL;
 		}
diff --git a/net/unix/scm.c b/net/unix/scm.c
index 6ff628f2349f..822ce0d0d791 100644
--- a/net/unix/scm.c
+++ b/net/unix/scm.c
@@ -35,10 +35,8 @@ struct sock *unix_get_socket(struct file *filp)
 		/* PF_UNIX ? */
 		if (s && ops && ops->family == PF_UNIX)
 			u_sock = s;
-	} else {
-		/* Could be an io_uring instance */
-		u_sock = io_uring_get_socket(filp);
 	}
+
 	return u_sock;
 }
 EXPORT_SYMBOL(unix_get_socket);
-- 
2.43.0


[-- Attachment #5: 6.7-0002-io_uring-drop-any-code-related-to-SCM_RIGHTS.patch --]
[-- Type: text/x-patch, Size: 11051 bytes --]

From e742473ca70a1fb2492451bf4959d0e94a0c1c7c Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@kernel.dk>
Date: Tue, 19 Dec 2023 12:36:34 -0700
Subject: [PATCH 2/2] io_uring: drop any code related to SCM_RIGHTS

Commit 6e5e6d274956305f1fc0340522b38f5f5be74bdb upstream.

This is dead code after we dropped support for passing io_uring fds
over SCM_RIGHTS, get rid of it.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 include/linux/io_uring_types.h |   3 -
 io_uring/filetable.c           |  11 +--
 io_uring/io_uring.c            |  32 +------
 io_uring/rsrc.c                | 169 +--------------------------------
 io_uring/rsrc.h                |  15 ---
 5 files changed, 10 insertions(+), 220 deletions(-)

diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h
index 239a4f68801b..335eca49dc8b 100644
--- a/include/linux/io_uring_types.h
+++ b/include/linux/io_uring_types.h
@@ -358,9 +358,6 @@ struct io_ring_ctx {
 	struct wait_queue_head		rsrc_quiesce_wq;
 	unsigned			rsrc_quiesce;
 
-	#if defined(CONFIG_UNIX)
-		struct socket		*ring_sock;
-	#endif
 	/* hashed buffered write serialization */
 	struct io_wq_hash		*hash_map;
 
diff --git a/io_uring/filetable.c b/io_uring/filetable.c
index e7d749991de4..6e86e6188dbe 100644
--- a/io_uring/filetable.c
+++ b/io_uring/filetable.c
@@ -87,13 +87,10 @@ static int io_install_fixed_file(struct io_ring_ctx *ctx, struct file *file,
 		io_file_bitmap_clear(&ctx->file_table, slot_index);
 	}
 
-	ret = io_scm_file_account(ctx, file);
-	if (!ret) {
-		*io_get_tag_slot(ctx->file_data, slot_index) = 0;
-		io_fixed_file_set(file_slot, file);
-		io_file_bitmap_set(&ctx->file_table, slot_index);
-	}
-	return ret;
+	*io_get_tag_slot(ctx->file_data, slot_index) = 0;
+	io_fixed_file_set(file_slot, file);
+	io_file_bitmap_set(&ctx->file_table, slot_index);
+	return 0;
 }
 
 int __io_fixed_fd_install(struct io_ring_ctx *ctx, struct file *file,
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 06bd8795a87d..f8d145fb40bb 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -60,7 +60,6 @@
 #include <linux/net.h>
 #include <net/sock.h>
 #include <net/af_unix.h>
-#include <net/scm.h>
 #include <linux/anon_inodes.h>
 #include <linux/sched/mm.h>
 #include <linux/uaccess.h>
@@ -2939,13 +2938,6 @@ static __cold void io_ring_ctx_free(struct io_ring_ctx *ctx)
 		io_rsrc_node_destroy(ctx, ctx->rsrc_node);
 
 	WARN_ON_ONCE(!list_empty(&ctx->rsrc_ref_list));
-
-#if defined(CONFIG_UNIX)
-	if (ctx->ring_sock) {
-		ctx->ring_sock->file = NULL; /* so that iput() is called */
-		sock_release(ctx->ring_sock);
-	}
-#endif
 	WARN_ON_ONCE(!list_empty(&ctx->ltimeout_list));
 
 	io_alloc_cache_free(&ctx->rsrc_node_cache, io_rsrc_node_cache_free);
@@ -3867,32 +3859,12 @@ static int io_uring_install_fd(struct file *file)
 /*
  * Allocate an anonymous fd, this is what constitutes the application
  * visible backing of an io_uring instance. The application mmaps this
- * fd to gain access to the SQ/CQ ring details. If UNIX sockets are enabled,
- * we have to tie this fd to a socket for file garbage collection purposes.
+ * fd to gain access to the SQ/CQ ring details.
  */
 static struct file *io_uring_get_file(struct io_ring_ctx *ctx)
 {
-	struct file *file;
-#if defined(CONFIG_UNIX)
-	int ret;
-
-	ret = sock_create_kern(&init_net, PF_UNIX, SOCK_RAW, IPPROTO_IP,
-				&ctx->ring_sock);
-	if (ret)
-		return ERR_PTR(ret);
-#endif
-
-	file = anon_inode_getfile_secure("[io_uring]", &io_uring_fops, ctx,
+	return anon_inode_getfile_secure("[io_uring]", &io_uring_fops, ctx,
 					 O_RDWR | O_CLOEXEC, NULL);
-#if defined(CONFIG_UNIX)
-	if (IS_ERR(file)) {
-		sock_release(ctx->ring_sock);
-		ctx->ring_sock = NULL;
-	} else {
-		ctx->ring_sock->file = file;
-	}
-#endif
-	return file;
 }
 
 static __cold int io_uring_create(unsigned entries, struct io_uring_params *p,
diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c
index f521c5965a93..4818b79231dd 100644
--- a/io_uring/rsrc.c
+++ b/io_uring/rsrc.c
@@ -24,7 +24,6 @@ struct io_rsrc_update {
 };
 
 static void io_rsrc_buf_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc);
-static void io_rsrc_file_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc);
 static int io_sqe_buffer_register(struct io_ring_ctx *ctx, struct iovec *iov,
 				  struct io_mapped_ubuf **pimu,
 				  struct page **last_hpage);
@@ -157,7 +156,7 @@ static void io_rsrc_put_work(struct io_rsrc_node *node)
 
 	switch (node->type) {
 	case IORING_RSRC_FILE:
-		io_rsrc_file_put(node->ctx, prsrc);
+		fput(prsrc->file);
 		break;
 	case IORING_RSRC_BUFFER:
 		io_rsrc_buf_put(node->ctx, prsrc);
@@ -402,23 +401,13 @@ static int __io_sqe_files_update(struct io_ring_ctx *ctx,
 				break;
 			}
 			/*
-			 * Don't allow io_uring instances to be registered. If
-			 * UNIX isn't enabled, then this causes a reference
-			 * cycle and this instance can never get freed. If UNIX
-			 * is enabled we'll handle it just fine, but there's
-			 * still no point in allowing a ring fd as it doesn't
-			 * support regular read/write anyway.
+			 * Don't allow io_uring instances to be registered.
 			 */
 			if (io_is_uring_fops(file)) {
 				fput(file);
 				err = -EBADF;
 				break;
 			}
-			err = io_scm_file_account(ctx, file);
-			if (err) {
-				fput(file);
-				break;
-			}
 			*io_get_tag_slot(data, i) = tag;
 			io_fixed_file_set(file_slot, file);
 			io_file_bitmap_set(&ctx->file_table, i);
@@ -675,22 +664,12 @@ void __io_sqe_files_unregister(struct io_ring_ctx *ctx)
 	for (i = 0; i < ctx->nr_user_files; i++) {
 		struct file *file = io_file_from_index(&ctx->file_table, i);
 
-		/* skip scm accounted files, they'll be freed by ->ring_sock */
-		if (!file || io_file_need_scm(file))
+		if (!file)
 			continue;
 		io_file_bitmap_clear(&ctx->file_table, i);
 		fput(file);
 	}
 
-#if defined(CONFIG_UNIX)
-	if (ctx->ring_sock) {
-		struct sock *sock = ctx->ring_sock->sk;
-		struct sk_buff *skb;
-
-		while ((skb = skb_dequeue(&sock->sk_receive_queue)) != NULL)
-			kfree_skb(skb);
-	}
-#endif
 	io_free_file_tables(&ctx->file_table);
 	io_file_table_set_alloc_range(ctx, 0, 0);
 	io_rsrc_data_free(ctx->file_data);
@@ -718,137 +697,6 @@ int io_sqe_files_unregister(struct io_ring_ctx *ctx)
 	return ret;
 }
 
-/*
- * Ensure the UNIX gc is aware of our file set, so we are certain that
- * the io_uring can be safely unregistered on process exit, even if we have
- * loops in the file referencing. We account only files that can hold other
- * files because otherwise they can't form a loop and so are not interesting
- * for GC.
- */
-int __io_scm_file_account(struct io_ring_ctx *ctx, struct file *file)
-{
-#if defined(CONFIG_UNIX)
-	struct sock *sk = ctx->ring_sock->sk;
-	struct sk_buff_head *head = &sk->sk_receive_queue;
-	struct scm_fp_list *fpl;
-	struct sk_buff *skb;
-
-	if (likely(!io_file_need_scm(file)))
-		return 0;
-
-	/*
-	 * See if we can merge this file into an existing skb SCM_RIGHTS
-	 * file set. If there's no room, fall back to allocating a new skb
-	 * and filling it in.
-	 */
-	spin_lock_irq(&head->lock);
-	skb = skb_peek(head);
-	if (skb && UNIXCB(skb).fp->count < SCM_MAX_FD)
-		__skb_unlink(skb, head);
-	else
-		skb = NULL;
-	spin_unlock_irq(&head->lock);
-
-	if (!skb) {
-		fpl = kzalloc(sizeof(*fpl), GFP_KERNEL);
-		if (!fpl)
-			return -ENOMEM;
-
-		skb = alloc_skb(0, GFP_KERNEL);
-		if (!skb) {
-			kfree(fpl);
-			return -ENOMEM;
-		}
-
-		fpl->user = get_uid(current_user());
-		fpl->max = SCM_MAX_FD;
-		fpl->count = 0;
-
-		UNIXCB(skb).fp = fpl;
-		skb->sk = sk;
-		skb->destructor = io_uring_destruct_scm;
-		refcount_add(skb->truesize, &sk->sk_wmem_alloc);
-	}
-
-	fpl = UNIXCB(skb).fp;
-	fpl->fp[fpl->count++] = get_file(file);
-	unix_inflight(fpl->user, file);
-	skb_queue_head(head, skb);
-	fput(file);
-#endif
-	return 0;
-}
-
-static __cold void io_rsrc_file_scm_put(struct io_ring_ctx *ctx, struct file *file)
-{
-#if defined(CONFIG_UNIX)
-	struct sock *sock = ctx->ring_sock->sk;
-	struct sk_buff_head list, *head = &sock->sk_receive_queue;
-	struct sk_buff *skb;
-	int i;
-
-	__skb_queue_head_init(&list);
-
-	/*
-	 * Find the skb that holds this file in its SCM_RIGHTS. When found,
-	 * remove this entry and rearrange the file array.
-	 */
-	skb = skb_dequeue(head);
-	while (skb) {
-		struct scm_fp_list *fp;
-
-		fp = UNIXCB(skb).fp;
-		for (i = 0; i < fp->count; i++) {
-			int left;
-
-			if (fp->fp[i] != file)
-				continue;
-
-			unix_notinflight(fp->user, fp->fp[i]);
-			left = fp->count - 1 - i;
-			if (left) {
-				memmove(&fp->fp[i], &fp->fp[i + 1],
-						left * sizeof(struct file *));
-			}
-			fp->count--;
-			if (!fp->count) {
-				kfree_skb(skb);
-				skb = NULL;
-			} else {
-				__skb_queue_tail(&list, skb);
-			}
-			fput(file);
-			file = NULL;
-			break;
-		}
-
-		if (!file)
-			break;
-
-		__skb_queue_tail(&list, skb);
-
-		skb = skb_dequeue(head);
-	}
-
-	if (skb_peek(&list)) {
-		spin_lock_irq(&head->lock);
-		while ((skb = __skb_dequeue(&list)) != NULL)
-			__skb_queue_tail(head, skb);
-		spin_unlock_irq(&head->lock);
-	}
-#endif
-}
-
-static void io_rsrc_file_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc)
-{
-	struct file *file = prsrc->file;
-
-	if (likely(!io_file_need_scm(file)))
-		fput(file);
-	else
-		io_rsrc_file_scm_put(ctx, file);
-}
-
 int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
 			  unsigned nr_args, u64 __user *tags)
 {
@@ -897,21 +745,12 @@ int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
 			goto fail;
 
 		/*
-		 * Don't allow io_uring instances to be registered. If UNIX
-		 * isn't enabled, then this causes a reference cycle and this
-		 * instance can never get freed. If UNIX is enabled we'll
-		 * handle it just fine, but there's still no point in allowing
-		 * a ring fd as it doesn't support regular read/write anyway.
+		 * Don't allow io_uring instances to be registered.
 		 */
 		if (io_is_uring_fops(file)) {
 			fput(file);
 			goto fail;
 		}
-		ret = io_scm_file_account(ctx, file);
-		if (ret) {
-			fput(file);
-			goto fail;
-		}
 		file_slot = io_fixed_file_slot(&ctx->file_table, i);
 		io_fixed_file_set(file_slot, file);
 		io_file_bitmap_set(&ctx->file_table, i);
diff --git a/io_uring/rsrc.h b/io_uring/rsrc.h
index 08ac0d8e07ef..7238b9cfe33b 100644
--- a/io_uring/rsrc.h
+++ b/io_uring/rsrc.h
@@ -75,21 +75,6 @@ int io_sqe_files_unregister(struct io_ring_ctx *ctx);
 int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
 			  unsigned nr_args, u64 __user *tags);
 
-int __io_scm_file_account(struct io_ring_ctx *ctx, struct file *file);
-
-static inline bool io_file_need_scm(struct file *filp)
-{
-	return false;
-}
-
-static inline int io_scm_file_account(struct io_ring_ctx *ctx,
-				      struct file *file)
-{
-	if (likely(!io_file_need_scm(file)))
-		return 0;
-	return __io_scm_file_account(ctx, file);
-}
-
 int io_register_files_update(struct io_ring_ctx *ctx, void __user *arg,
 			     unsigned nr_args);
 int io_register_rsrc_update(struct io_ring_ctx *ctx, void __user *arg,
-- 
2.43.0


[-- Attachment #6: 6.6-0002-io_uring-drop-any-code-related-to-SCM_RIGHTS.patch --]
[-- Type: text/x-patch, Size: 10962 bytes --]

From cbe948d42e1ff43e77d60f21823d3d798f92835e Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@kernel.dk>
Date: Tue, 19 Dec 2023 12:36:34 -0700
Subject: [PATCH 2/2] io_uring: drop any code related to SCM_RIGHTS

This is dead code after we dropped support for passing io_uring fds
over SCM_RIGHTS, get rid of it.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 include/linux/io_uring_types.h |   3 -
 io_uring/filetable.c           |  11 +--
 io_uring/io_uring.c            |  32 +------
 io_uring/rsrc.c                | 169 +--------------------------------
 io_uring/rsrc.h                |  15 ---
 5 files changed, 10 insertions(+), 220 deletions(-)

diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h
index 5fd664fb71c8..731beb3198c4 100644
--- a/include/linux/io_uring_types.h
+++ b/include/linux/io_uring_types.h
@@ -347,9 +347,6 @@ struct io_ring_ctx {
 
 	struct list_head		io_buffers_pages;
 
-	#if defined(CONFIG_UNIX)
-		struct socket		*ring_sock;
-	#endif
 	/* hashed buffered write serialization */
 	struct io_wq_hash		*hash_map;
 
diff --git a/io_uring/filetable.c b/io_uring/filetable.c
index e7d749991de4..6e86e6188dbe 100644
--- a/io_uring/filetable.c
+++ b/io_uring/filetable.c
@@ -87,13 +87,10 @@ static int io_install_fixed_file(struct io_ring_ctx *ctx, struct file *file,
 		io_file_bitmap_clear(&ctx->file_table, slot_index);
 	}
 
-	ret = io_scm_file_account(ctx, file);
-	if (!ret) {
-		*io_get_tag_slot(ctx->file_data, slot_index) = 0;
-		io_fixed_file_set(file_slot, file);
-		io_file_bitmap_set(&ctx->file_table, slot_index);
-	}
-	return ret;
+	*io_get_tag_slot(ctx->file_data, slot_index) = 0;
+	io_fixed_file_set(file_slot, file);
+	io_file_bitmap_set(&ctx->file_table, slot_index);
+	return 0;
 }
 
 int __io_fixed_fd_install(struct io_ring_ctx *ctx, struct file *file,
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 747d2a6ecab8..2744d72f1085 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -60,7 +60,6 @@
 #include <linux/net.h>
 #include <net/sock.h>
 #include <net/af_unix.h>
-#include <net/scm.h>
 #include <linux/anon_inodes.h>
 #include <linux/sched/mm.h>
 #include <linux/uaccess.h>
@@ -2931,13 +2930,6 @@ static __cold void io_ring_ctx_free(struct io_ring_ctx *ctx)
 		io_rsrc_node_destroy(ctx, ctx->rsrc_node);
 
 	WARN_ON_ONCE(!list_empty(&ctx->rsrc_ref_list));
-
-#if defined(CONFIG_UNIX)
-	if (ctx->ring_sock) {
-		ctx->ring_sock->file = NULL; /* so that iput() is called */
-		sock_release(ctx->ring_sock);
-	}
-#endif
 	WARN_ON_ONCE(!list_empty(&ctx->ltimeout_list));
 
 	io_alloc_cache_free(&ctx->rsrc_node_cache, io_rsrc_node_cache_free);
@@ -3825,32 +3817,12 @@ static int io_uring_install_fd(struct file *file)
 /*
  * Allocate an anonymous fd, this is what constitutes the application
  * visible backing of an io_uring instance. The application mmaps this
- * fd to gain access to the SQ/CQ ring details. If UNIX sockets are enabled,
- * we have to tie this fd to a socket for file garbage collection purposes.
+ * fd to gain access to the SQ/CQ ring details.
  */
 static struct file *io_uring_get_file(struct io_ring_ctx *ctx)
 {
-	struct file *file;
-#if defined(CONFIG_UNIX)
-	int ret;
-
-	ret = sock_create_kern(&init_net, PF_UNIX, SOCK_RAW, IPPROTO_IP,
-				&ctx->ring_sock);
-	if (ret)
-		return ERR_PTR(ret);
-#endif
-
-	file = anon_inode_getfile_secure("[io_uring]", &io_uring_fops, ctx,
+	return anon_inode_getfile_secure("[io_uring]", &io_uring_fops, ctx,
 					 O_RDWR | O_CLOEXEC, NULL);
-#if defined(CONFIG_UNIX)
-	if (IS_ERR(file)) {
-		sock_release(ctx->ring_sock);
-		ctx->ring_sock = NULL;
-	} else {
-		ctx->ring_sock->file = file;
-	}
-#endif
-	return file;
 }
 
 static __cold int io_uring_create(unsigned entries, struct io_uring_params *p,
diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c
index dde501abd719..95230921b16d 100644
--- a/io_uring/rsrc.c
+++ b/io_uring/rsrc.c
@@ -24,7 +24,6 @@ struct io_rsrc_update {
 };
 
 static void io_rsrc_buf_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc);
-static void io_rsrc_file_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc);
 static int io_sqe_buffer_register(struct io_ring_ctx *ctx, struct iovec *iov,
 				  struct io_mapped_ubuf **pimu,
 				  struct page **last_hpage);
@@ -157,7 +156,7 @@ static void io_rsrc_put_work(struct io_rsrc_node *node)
 
 	switch (node->type) {
 	case IORING_RSRC_FILE:
-		io_rsrc_file_put(node->ctx, prsrc);
+		fput(prsrc->file);
 		break;
 	case IORING_RSRC_BUFFER:
 		io_rsrc_buf_put(node->ctx, prsrc);
@@ -402,23 +401,13 @@ static int __io_sqe_files_update(struct io_ring_ctx *ctx,
 				break;
 			}
 			/*
-			 * Don't allow io_uring instances to be registered. If
-			 * UNIX isn't enabled, then this causes a reference
-			 * cycle and this instance can never get freed. If UNIX
-			 * is enabled we'll handle it just fine, but there's
-			 * still no point in allowing a ring fd as it doesn't
-			 * support regular read/write anyway.
+			 * Don't allow io_uring instances to be registered.
 			 */
 			if (io_is_uring_fops(file)) {
 				fput(file);
 				err = -EBADF;
 				break;
 			}
-			err = io_scm_file_account(ctx, file);
-			if (err) {
-				fput(file);
-				break;
-			}
 			*io_get_tag_slot(data, i) = tag;
 			io_fixed_file_set(file_slot, file);
 			io_file_bitmap_set(&ctx->file_table, i);
@@ -675,22 +664,12 @@ void __io_sqe_files_unregister(struct io_ring_ctx *ctx)
 	for (i = 0; i < ctx->nr_user_files; i++) {
 		struct file *file = io_file_from_index(&ctx->file_table, i);
 
-		/* skip scm accounted files, they'll be freed by ->ring_sock */
-		if (!file || io_file_need_scm(file))
+		if (!file)
 			continue;
 		io_file_bitmap_clear(&ctx->file_table, i);
 		fput(file);
 	}
 
-#if defined(CONFIG_UNIX)
-	if (ctx->ring_sock) {
-		struct sock *sock = ctx->ring_sock->sk;
-		struct sk_buff *skb;
-
-		while ((skb = skb_dequeue(&sock->sk_receive_queue)) != NULL)
-			kfree_skb(skb);
-	}
-#endif
 	io_free_file_tables(&ctx->file_table);
 	io_file_table_set_alloc_range(ctx, 0, 0);
 	io_rsrc_data_free(ctx->file_data);
@@ -718,137 +697,6 @@ int io_sqe_files_unregister(struct io_ring_ctx *ctx)
 	return ret;
 }
 
-/*
- * Ensure the UNIX gc is aware of our file set, so we are certain that
- * the io_uring can be safely unregistered on process exit, even if we have
- * loops in the file referencing. We account only files that can hold other
- * files because otherwise they can't form a loop and so are not interesting
- * for GC.
- */
-int __io_scm_file_account(struct io_ring_ctx *ctx, struct file *file)
-{
-#if defined(CONFIG_UNIX)
-	struct sock *sk = ctx->ring_sock->sk;
-	struct sk_buff_head *head = &sk->sk_receive_queue;
-	struct scm_fp_list *fpl;
-	struct sk_buff *skb;
-
-	if (likely(!io_file_need_scm(file)))
-		return 0;
-
-	/*
-	 * See if we can merge this file into an existing skb SCM_RIGHTS
-	 * file set. If there's no room, fall back to allocating a new skb
-	 * and filling it in.
-	 */
-	spin_lock_irq(&head->lock);
-	skb = skb_peek(head);
-	if (skb && UNIXCB(skb).fp->count < SCM_MAX_FD)
-		__skb_unlink(skb, head);
-	else
-		skb = NULL;
-	spin_unlock_irq(&head->lock);
-
-	if (!skb) {
-		fpl = kzalloc(sizeof(*fpl), GFP_KERNEL);
-		if (!fpl)
-			return -ENOMEM;
-
-		skb = alloc_skb(0, GFP_KERNEL);
-		if (!skb) {
-			kfree(fpl);
-			return -ENOMEM;
-		}
-
-		fpl->user = get_uid(current_user());
-		fpl->max = SCM_MAX_FD;
-		fpl->count = 0;
-
-		UNIXCB(skb).fp = fpl;
-		skb->sk = sk;
-		skb->destructor = io_uring_destruct_scm;
-		refcount_add(skb->truesize, &sk->sk_wmem_alloc);
-	}
-
-	fpl = UNIXCB(skb).fp;
-	fpl->fp[fpl->count++] = get_file(file);
-	unix_inflight(fpl->user, file);
-	skb_queue_head(head, skb);
-	fput(file);
-#endif
-	return 0;
-}
-
-static __cold void io_rsrc_file_scm_put(struct io_ring_ctx *ctx, struct file *file)
-{
-#if defined(CONFIG_UNIX)
-	struct sock *sock = ctx->ring_sock->sk;
-	struct sk_buff_head list, *head = &sock->sk_receive_queue;
-	struct sk_buff *skb;
-	int i;
-
-	__skb_queue_head_init(&list);
-
-	/*
-	 * Find the skb that holds this file in its SCM_RIGHTS. When found,
-	 * remove this entry and rearrange the file array.
-	 */
-	skb = skb_dequeue(head);
-	while (skb) {
-		struct scm_fp_list *fp;
-
-		fp = UNIXCB(skb).fp;
-		for (i = 0; i < fp->count; i++) {
-			int left;
-
-			if (fp->fp[i] != file)
-				continue;
-
-			unix_notinflight(fp->user, fp->fp[i]);
-			left = fp->count - 1 - i;
-			if (left) {
-				memmove(&fp->fp[i], &fp->fp[i + 1],
-						left * sizeof(struct file *));
-			}
-			fp->count--;
-			if (!fp->count) {
-				kfree_skb(skb);
-				skb = NULL;
-			} else {
-				__skb_queue_tail(&list, skb);
-			}
-			fput(file);
-			file = NULL;
-			break;
-		}
-
-		if (!file)
-			break;
-
-		__skb_queue_tail(&list, skb);
-
-		skb = skb_dequeue(head);
-	}
-
-	if (skb_peek(&list)) {
-		spin_lock_irq(&head->lock);
-		while ((skb = __skb_dequeue(&list)) != NULL)
-			__skb_queue_tail(head, skb);
-		spin_unlock_irq(&head->lock);
-	}
-#endif
-}
-
-static void io_rsrc_file_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc)
-{
-	struct file *file = prsrc->file;
-
-	if (likely(!io_file_need_scm(file)))
-		fput(file);
-	else
-		io_rsrc_file_scm_put(ctx, file);
-}
-
 int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
 			  unsigned nr_args, u64 __user *tags)
 {
@@ -897,21 +745,12 @@ int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
 			goto fail;
 
 		/*
-		 * Don't allow io_uring instances to be registered. If UNIX
-		 * isn't enabled, then this causes a reference cycle and this
-		 * instance can never get freed. If UNIX is enabled we'll
-		 * handle it just fine, but there's still no point in allowing
-		 * a ring fd as it doesn't support regular read/write anyway.
+		 * Don't allow io_uring instances to be registered.
 		 */
 		if (io_is_uring_fops(file)) {
 			fput(file);
 			goto fail;
 		}
-		ret = io_scm_file_account(ctx, file);
-		if (ret) {
-			fput(file);
-			goto fail;
-		}
 		file_slot = io_fixed_file_slot(&ctx->file_table, i);
 		io_fixed_file_set(file_slot, file);
 		io_file_bitmap_set(&ctx->file_table, i);
diff --git a/io_uring/rsrc.h b/io_uring/rsrc.h
index 08ac0d8e07ef..7238b9cfe33b 100644
--- a/io_uring/rsrc.h
+++ b/io_uring/rsrc.h
@@ -75,21 +75,6 @@ int io_sqe_files_unregister(struct io_ring_ctx *ctx);
 int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
 			  unsigned nr_args, u64 __user *tags);
 
-int __io_scm_file_account(struct io_ring_ctx *ctx, struct file *file);
-
-static inline bool io_file_need_scm(struct file *filp)
-{
-	return false;
-}
-
-static inline int io_scm_file_account(struct io_ring_ctx *ctx,
-				      struct file *file)
-{
-	if (likely(!io_file_need_scm(file)))
-		return 0;
-	return __io_scm_file_account(ctx, file);
-}
-
 int io_register_files_update(struct io_ring_ctx *ctx, void __user *arg,
 			     unsigned nr_args);
 int io_register_rsrc_update(struct io_ring_ctx *ctx, void __user *arg,
-- 
2.43.0


[-- Attachment #7: 6.6-0001-io_uring-unix-drop-usage-of-io_uring-socket.patch --]
[-- Type: text/x-patch, Size: 4367 bytes --]

From b706187d02eacef15922de5fafedd65bc2db0576 Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@kernel.dk>
Date: Tue, 19 Dec 2023 12:30:43 -0700
Subject: [PATCH 1/2] io_uring/unix: drop usage of io_uring socket

Commit a4104821ad651d8a0b374f0b2474c345bbb42f82 upstream.

Since we no longer allow sending io_uring fds over SCM_RIGHTS, move to
using io_is_uring_fops() to detect whether this is a io_uring fd or not.
With that done, kill off io_uring_get_socket() as nobody calls it
anymore.

This is in preparation to yanking out the rest of the core related to
unix gc with io_uring.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 include/linux/io_uring.h | 10 +++++-----
 io_uring/io_uring.c      | 13 -------------
 io_uring/io_uring.h      |  1 -
 net/core/scm.c           |  2 +-
 net/unix/scm.c           |  4 +---
 5 files changed, 7 insertions(+), 23 deletions(-)

diff --git a/include/linux/io_uring.h b/include/linux/io_uring.h
index 106cdc55ff3b..f99ff6de926c 100644
--- a/include/linux/io_uring.h
+++ b/include/linux/io_uring.h
@@ -46,7 +46,6 @@ int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
 			      struct iov_iter *iter, void *ioucmd);
 void io_uring_cmd_done(struct io_uring_cmd *cmd, ssize_t ret, ssize_t res2,
 			unsigned issue_flags);
-struct sock *io_uring_get_socket(struct file *file);
 void __io_uring_cancel(bool cancel_all);
 void __io_uring_free(struct task_struct *tsk);
 void io_uring_unreg_ringfd(void);
@@ -82,6 +81,7 @@ static inline void io_uring_free(struct task_struct *tsk)
 		__io_uring_free(tsk);
 }
 int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags);
+bool io_is_uring_fops(struct file *file);
 #else
 static inline int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
 			      struct iov_iter *iter, void *ioucmd)
@@ -100,10 +100,6 @@ static inline void io_uring_cmd_do_in_task_lazy(struct io_uring_cmd *ioucmd,
 			void (*task_work_cb)(struct io_uring_cmd *, unsigned))
 {
 }
-static inline struct sock *io_uring_get_socket(struct file *file)
-{
-	return NULL;
-}
 static inline void io_uring_task_cancel(void)
 {
 }
@@ -122,6 +118,10 @@ static inline int io_uring_cmd_sock(struct io_uring_cmd *cmd,
 {
 	return -EOPNOTSUPP;
 }
+static inline bool io_is_uring_fops(struct file *file)
+{
+	return false;
+}
 #endif
 
 #endif
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index ea772a02c140..747d2a6ecab8 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -175,19 +175,6 @@ static struct ctl_table kernel_io_uring_disabled_table[] = {
 };
 #endif
 
-struct sock *io_uring_get_socket(struct file *file)
-{
-#if defined(CONFIG_UNIX)
-	if (io_is_uring_fops(file)) {
-		struct io_ring_ctx *ctx = file->private_data;
-
-		return ctx->ring_sock->sk;
-	}
-#endif
-	return NULL;
-}
-EXPORT_SYMBOL(io_uring_get_socket);
-
 static inline void io_submit_flush_completions(struct io_ring_ctx *ctx)
 {
 	if (!wq_list_empty(&ctx->submit_state.compl_reqs) ||
diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h
index c8cba7831083..411c883b37a9 100644
--- a/io_uring/io_uring.h
+++ b/io_uring/io_uring.h
@@ -61,7 +61,6 @@ struct file *io_file_get_fixed(struct io_kiocb *req, int fd,
 			       unsigned issue_flags);
 
 void __io_req_task_work_add(struct io_kiocb *req, unsigned flags);
-bool io_is_uring_fops(struct file *file);
 bool io_alloc_async_data(struct io_kiocb *req);
 void io_req_task_queue(struct io_kiocb *req);
 void io_queue_iowq(struct io_kiocb *req, struct io_tw_state *ts_dont_use);
diff --git a/net/core/scm.c b/net/core/scm.c
index 7dc47c17d863..737917c7ac62 100644
--- a/net/core/scm.c
+++ b/net/core/scm.c
@@ -105,7 +105,7 @@ static int scm_fp_copy(struct cmsghdr *cmsg, struct scm_fp_list **fplp)
 		if (fd < 0 || !(file = fget_raw(fd)))
 			return -EBADF;
 		/* don't allow io_uring files */
-		if (io_uring_get_socket(file)) {
+		if (io_is_uring_fops(file)) {
 			fput(file);
 			return -EINVAL;
 		}
diff --git a/net/unix/scm.c b/net/unix/scm.c
index 6ff628f2349f..822ce0d0d791 100644
--- a/net/unix/scm.c
+++ b/net/unix/scm.c
@@ -35,10 +35,8 @@ struct sock *unix_get_socket(struct file *filp)
 		/* PF_UNIX ? */
 		if (s && ops && ops->family == PF_UNIX)
 			u_sock = s;
-	} else {
-		/* Could be an io_uring instance */
-		u_sock = io_uring_get_socket(filp);
 	}
+
 	return u_sock;
 }
 EXPORT_SYMBOL(unix_get_socket);
-- 
2.43.0


[-- Attachment #8: 6.1-0001-io_uring-unix-drop-usage-of-io_uring-socket.patch --]
[-- Type: text/x-patch, Size: 4272 bytes --]

From 42d0449f65e6632ddc638929c53676fb776d8412 Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@kernel.dk>
Date: Wed, 13 Mar 2024 18:10:12 -0600
Subject: [PATCH 1/2] io_uring/unix: drop usage of io_uring socket

Commit a4104821ad651d8a0b374f0b2474c345bbb42f82 upstream.

Since we no longer allow sending io_uring fds over SCM_RIGHTS, move to
using io_is_uring_fops() to detect whether this is a io_uring fd or not.
With that done, kill off io_uring_get_socket() as nobody calls it
anymore.

This is in preparation to yanking out the rest of the core related to
unix gc with io_uring.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 include/linux/io_uring.h | 10 +++++-----
 io_uring/io_uring.c      | 13 -------------
 io_uring/io_uring.h      |  1 -
 net/core/scm.c           |  2 +-
 net/unix/scm.c           |  4 +---
 5 files changed, 7 insertions(+), 23 deletions(-)

diff --git a/include/linux/io_uring.h b/include/linux/io_uring.h
index a1484cdb3158..a8f3058448ea 100644
--- a/include/linux/io_uring.h
+++ b/include/linux/io_uring.h
@@ -42,11 +42,11 @@ void io_uring_cmd_done(struct io_uring_cmd *cmd, ssize_t ret, ssize_t res2,
 			unsigned issue_flags);
 void io_uring_cmd_complete_in_task(struct io_uring_cmd *ioucmd,
 			void (*task_work_cb)(struct io_uring_cmd *, unsigned));
-struct sock *io_uring_get_socket(struct file *file);
 void __io_uring_cancel(bool cancel_all);
 void __io_uring_free(struct task_struct *tsk);
 void io_uring_unreg_ringfd(void);
 const char *io_uring_get_opcode(u8 opcode);
+bool io_is_uring_fops(struct file *file);
 
 static inline void io_uring_files_cancel(void)
 {
@@ -71,6 +71,10 @@ static inline int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
 {
 	return -EOPNOTSUPP;
 }
+static inline bool io_is_uring_fops(struct file *file)
+{
+	return false;
+}
 static inline void io_uring_cmd_done(struct io_uring_cmd *cmd, ssize_t ret,
 		ssize_t ret2, unsigned issue_flags)
 {
@@ -79,10 +83,6 @@ static inline void io_uring_cmd_complete_in_task(struct io_uring_cmd *ioucmd,
 			void (*task_work_cb)(struct io_uring_cmd *, unsigned))
 {
 }
-static inline struct sock *io_uring_get_socket(struct file *file)
-{
-	return NULL;
-}
 static inline void io_uring_task_cancel(void)
 {
 }
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 35894955b454..cf7dd62da0e3 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -153,19 +153,6 @@ static void __io_submit_flush_completions(struct io_ring_ctx *ctx);
 
 static struct kmem_cache *req_cachep;
 
-struct sock *io_uring_get_socket(struct file *file)
-{
-#if defined(CONFIG_UNIX)
-	if (io_is_uring_fops(file)) {
-		struct io_ring_ctx *ctx = file->private_data;
-
-		return ctx->ring_sock->sk;
-	}
-#endif
-	return NULL;
-}
-EXPORT_SYMBOL(io_uring_get_socket);
-
 static inline void io_submit_flush_completions(struct io_ring_ctx *ctx)
 {
 	if (!wq_list_empty(&ctx->submit_state.compl_reqs))
diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h
index 019600570ee4..59e6f755f12c 100644
--- a/io_uring/io_uring.h
+++ b/io_uring/io_uring.h
@@ -52,7 +52,6 @@ static inline bool io_req_ffs_set(struct io_kiocb *req)
 }
 
 void __io_req_task_work_add(struct io_kiocb *req, bool allow_local);
-bool io_is_uring_fops(struct file *file);
 bool io_alloc_async_data(struct io_kiocb *req);
 void io_req_task_queue(struct io_kiocb *req);
 void io_queue_iowq(struct io_kiocb *req, bool *dont_use);
diff --git a/net/core/scm.c b/net/core/scm.c
index e762a4b8a1d2..a877c4ef4c25 100644
--- a/net/core/scm.c
+++ b/net/core/scm.c
@@ -105,7 +105,7 @@ static int scm_fp_copy(struct cmsghdr *cmsg, struct scm_fp_list **fplp)
 		if (fd < 0 || !(file = fget_raw(fd)))
 			return -EBADF;
 		/* don't allow io_uring files */
-		if (io_uring_get_socket(file)) {
+		if (io_is_uring_fops(file)) {
 			fput(file);
 			return -EINVAL;
 		}
diff --git a/net/unix/scm.c b/net/unix/scm.c
index e8e2a00bb0f5..d1048b4c2baa 100644
--- a/net/unix/scm.c
+++ b/net/unix/scm.c
@@ -34,10 +34,8 @@ struct sock *unix_get_socket(struct file *filp)
 		/* PF_UNIX ? */
 		if (s && sock->ops && sock->ops->family == PF_UNIX)
 			u_sock = s;
-	} else {
-		/* Could be an io_uring instance */
-		u_sock = io_uring_get_socket(filp);
 	}
+
 	return u_sock;
 }
 EXPORT_SYMBOL(unix_get_socket);
-- 
2.43.0


[-- Attachment #9: 6.1-0002-io_uring-drop-any-code-related-to-SCM_RIGHTS.patch --]
[-- Type: text/x-patch, Size: 9727 bytes --]

From 083974002b6f45bb84090a9aed025d8a3d8479cb Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@kernel.dk>
Date: Wed, 13 Mar 2024 18:15:05 -0600
Subject: [PATCH 2/2] io_uring: drop any code related to SCM_RIGHTS

Commit 6e5e6d274956305f1fc0340522b38f5f5be74bdb upstream.

This is dead code after we dropped support for passing io_uring fds
over SCM_RIGHTS, get rid of it.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 include/linux/io_uring_types.h |   3 -
 io_uring/filetable.c           |  10 +--
 io_uring/io_uring.c            |  31 +------
 io_uring/rsrc.c                | 151 +--------------------------------
 io_uring/rsrc.h                |  15 ----
 5 files changed, 8 insertions(+), 202 deletions(-)

diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h
index f5b687a787a3..37aeea266ebb 100644
--- a/include/linux/io_uring_types.h
+++ b/include/linux/io_uring_types.h
@@ -330,9 +330,6 @@ struct io_ring_ctx {
 
 	struct list_head		io_buffers_pages;
 
-	#if defined(CONFIG_UNIX)
-		struct socket		*ring_sock;
-	#endif
 	/* hashed buffered write serialization */
 	struct io_wq_hash		*hash_map;
 
diff --git a/io_uring/filetable.c b/io_uring/filetable.c
index b80614e7d605..4660cb89ea9f 100644
--- a/io_uring/filetable.c
+++ b/io_uring/filetable.c
@@ -95,12 +95,10 @@ static int io_install_fixed_file(struct io_ring_ctx *ctx, struct file *file,
 		needs_switch = true;
 	}
 
-	ret = io_scm_file_account(ctx, file);
-	if (!ret) {
-		*io_get_tag_slot(ctx->file_data, slot_index) = 0;
-		io_fixed_file_set(file_slot, file);
-		io_file_bitmap_set(&ctx->file_table, slot_index);
-	}
+	*io_get_tag_slot(ctx->file_data, slot_index) = 0;
+	io_fixed_file_set(file_slot, file);
+	io_file_bitmap_set(&ctx->file_table, slot_index);
+	return 0;
 err:
 	if (needs_switch)
 		io_rsrc_node_switch(ctx, ctx->file_data);
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index cf7dd62da0e3..415248c1f82c 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -60,7 +60,6 @@
 #include <linux/net.h>
 #include <net/sock.h>
 #include <net/af_unix.h>
-#include <net/scm.h>
 #include <linux/anon_inodes.h>
 #include <linux/sched/mm.h>
 #include <linux/uaccess.h>
@@ -2628,12 +2627,6 @@ static __cold void io_ring_ctx_free(struct io_ring_ctx *ctx)
 	WARN_ON_ONCE(!list_empty(&ctx->rsrc_ref_list));
 	WARN_ON_ONCE(!llist_empty(&ctx->rsrc_put_llist));
 
-#if defined(CONFIG_UNIX)
-	if (ctx->ring_sock) {
-		ctx->ring_sock->file = NULL; /* so that iput() is called */
-		sock_release(ctx->ring_sock);
-	}
-#endif
 	WARN_ON_ONCE(!list_empty(&ctx->ltimeout_list));
 
 	if (ctx->mm_account) {
@@ -3438,32 +3431,12 @@ static int io_uring_install_fd(struct io_ring_ctx *ctx, struct file *file)
 /*
  * Allocate an anonymous fd, this is what constitutes the application
  * visible backing of an io_uring instance. The application mmaps this
- * fd to gain access to the SQ/CQ ring details. If UNIX sockets are enabled,
- * we have to tie this fd to a socket for file garbage collection purposes.
+ * fd to gain access to the SQ/CQ ring details.
  */
 static struct file *io_uring_get_file(struct io_ring_ctx *ctx)
 {
-	struct file *file;
-#if defined(CONFIG_UNIX)
-	int ret;
-
-	ret = sock_create_kern(&init_net, PF_UNIX, SOCK_RAW, IPPROTO_IP,
-				&ctx->ring_sock);
-	if (ret)
-		return ERR_PTR(ret);
-#endif
-
-	file = anon_inode_getfile_secure("[io_uring]", &io_uring_fops, ctx,
+	return anon_inode_getfile_secure("[io_uring]", &io_uring_fops, ctx,
 					 O_RDWR | O_CLOEXEC, NULL);
-#if defined(CONFIG_UNIX)
-	if (IS_ERR(file)) {
-		sock_release(ctx->ring_sock);
-		ctx->ring_sock = NULL;
-	} else {
-		ctx->ring_sock->file = file;
-	}
-#endif
-	return file;
 }
 
 static __cold int io_uring_create(unsigned entries, struct io_uring_params *p,
diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c
index 7ada0339b387..ac658cfa89c6 100644
--- a/io_uring/rsrc.c
+++ b/io_uring/rsrc.c
@@ -494,11 +494,6 @@ static int __io_sqe_files_update(struct io_ring_ctx *ctx,
 				err = -EBADF;
 				break;
 			}
-			err = io_scm_file_account(ctx, file);
-			if (err) {
-				fput(file);
-				break;
-			}
 			*io_get_tag_slot(data, i) = tag;
 			io_fixed_file_set(file_slot, file);
 			io_file_bitmap_set(&ctx->file_table, i);
@@ -762,22 +757,12 @@ void __io_sqe_files_unregister(struct io_ring_ctx *ctx)
 	for (i = 0; i < ctx->nr_user_files; i++) {
 		struct file *file = io_file_from_index(&ctx->file_table, i);
 
-		/* skip scm accounted files, they'll be freed by ->ring_sock */
-		if (!file || io_file_need_scm(file))
+		if (!file)
 			continue;
 		io_file_bitmap_clear(&ctx->file_table, i);
 		fput(file);
 	}
 
-#if defined(CONFIG_UNIX)
-	if (ctx->ring_sock) {
-		struct sock *sock = ctx->ring_sock->sk;
-		struct sk_buff *skb;
-
-		while ((skb = skb_dequeue(&sock->sk_receive_queue)) != NULL)
-			kfree_skb(skb);
-	}
-#endif
 	io_free_file_tables(&ctx->file_table);
 	io_file_table_set_alloc_range(ctx, 0, 0);
 	io_rsrc_data_free(ctx->file_data);
@@ -805,134 +790,11 @@ int io_sqe_files_unregister(struct io_ring_ctx *ctx)
 	return ret;
 }
 
-/*
- * Ensure the UNIX gc is aware of our file set, so we are certain that
- * the io_uring can be safely unregistered on process exit, even if we have
- * loops in the file referencing. We account only files that can hold other
- * files because otherwise they can't form a loop and so are not interesting
- * for GC.
- */
-int __io_scm_file_account(struct io_ring_ctx *ctx, struct file *file)
-{
-#if defined(CONFIG_UNIX)
-	struct sock *sk = ctx->ring_sock->sk;
-	struct sk_buff_head *head = &sk->sk_receive_queue;
-	struct scm_fp_list *fpl;
-	struct sk_buff *skb;
-
-	if (likely(!io_file_need_scm(file)))
-		return 0;
-
-	/*
-	 * See if we can merge this file into an existing skb SCM_RIGHTS
-	 * file set. If there's no room, fall back to allocating a new skb
-	 * and filling it in.
-	 */
-	spin_lock_irq(&head->lock);
-	skb = skb_peek(head);
-	if (skb && UNIXCB(skb).fp->count < SCM_MAX_FD)
-		__skb_unlink(skb, head);
-	else
-		skb = NULL;
-	spin_unlock_irq(&head->lock);
-
-	if (!skb) {
-		fpl = kzalloc(sizeof(*fpl), GFP_KERNEL);
-		if (!fpl)
-			return -ENOMEM;
-
-		skb = alloc_skb(0, GFP_KERNEL);
-		if (!skb) {
-			kfree(fpl);
-			return -ENOMEM;
-		}
-
-		fpl->user = get_uid(current_user());
-		fpl->max = SCM_MAX_FD;
-		fpl->count = 0;
-
-		UNIXCB(skb).fp = fpl;
-		skb->sk = sk;
-		skb->scm_io_uring = 1;
-		skb->destructor = unix_destruct_scm;
-		refcount_add(skb->truesize, &sk->sk_wmem_alloc);
-	}
-
-	fpl = UNIXCB(skb).fp;
-	fpl->fp[fpl->count++] = get_file(file);
-	unix_inflight(fpl->user, file);
-	skb_queue_head(head, skb);
-	fput(file);
-#endif
-	return 0;
-}
-
 static void io_rsrc_file_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc)
 {
 	struct file *file = prsrc->file;
-#if defined(CONFIG_UNIX)
-	struct sock *sock = ctx->ring_sock->sk;
-	struct sk_buff_head list, *head = &sock->sk_receive_queue;
-	struct sk_buff *skb;
-	int i;
-
-	if (!io_file_need_scm(file)) {
-		fput(file);
-		return;
-	}
-
-	__skb_queue_head_init(&list);
-
-	/*
-	 * Find the skb that holds this file in its SCM_RIGHTS. When found,
-	 * remove this entry and rearrange the file array.
-	 */
-	skb = skb_dequeue(head);
-	while (skb) {
-		struct scm_fp_list *fp;
 
-		fp = UNIXCB(skb).fp;
-		for (i = 0; i < fp->count; i++) {
-			int left;
-
-			if (fp->fp[i] != file)
-				continue;
-
-			unix_notinflight(fp->user, fp->fp[i]);
-			left = fp->count - 1 - i;
-			if (left) {
-				memmove(&fp->fp[i], &fp->fp[i + 1],
-						left * sizeof(struct file *));
-			}
-			fp->count--;
-			if (!fp->count) {
-				kfree_skb(skb);
-				skb = NULL;
-			} else {
-				__skb_queue_tail(&list, skb);
-			}
-			fput(file);
-			file = NULL;
-			break;
-		}
-
-		if (!file)
-			break;
-
-		__skb_queue_tail(&list, skb);
-
-		skb = skb_dequeue(head);
-	}
-
-	if (skb_peek(&list)) {
-		spin_lock_irq(&head->lock);
-		while ((skb = __skb_dequeue(&list)) != NULL)
-			__skb_queue_tail(head, skb);
-		spin_unlock_irq(&head->lock);
-	}
-#else
 	fput(file);
-#endif
 }
 
 int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
@@ -986,21 +848,12 @@ int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
 			goto fail;
 
 		/*
-		 * Don't allow io_uring instances to be registered. If UNIX
-		 * isn't enabled, then this causes a reference cycle and this
-		 * instance can never get freed. If UNIX is enabled we'll
-		 * handle it just fine, but there's still no point in allowing
-		 * a ring fd as it doesn't support regular read/write anyway.
+		 * Don't allow io_uring instances to be registered.
 		 */
 		if (io_is_uring_fops(file)) {
 			fput(file);
 			goto fail;
 		}
-		ret = io_scm_file_account(ctx, file);
-		if (ret) {
-			fput(file);
-			goto fail;
-		}
 		file_slot = io_fixed_file_slot(&ctx->file_table, i);
 		io_fixed_file_set(file_slot, file);
 		io_file_bitmap_set(&ctx->file_table, i);
diff --git a/io_uring/rsrc.h b/io_uring/rsrc.h
index acaf8dad0540..85f145607c62 100644
--- a/io_uring/rsrc.h
+++ b/io_uring/rsrc.h
@@ -77,21 +77,6 @@ int io_sqe_files_unregister(struct io_ring_ctx *ctx);
 int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
 			  unsigned nr_args, u64 __user *tags);
 
-int __io_scm_file_account(struct io_ring_ctx *ctx, struct file *file);
-
-static inline bool io_file_need_scm(struct file *filp)
-{
-	return false;
-}
-
-static inline int io_scm_file_account(struct io_ring_ctx *ctx,
-				      struct file *file)
-{
-	if (likely(!io_file_need_scm(file)))
-		return 0;
-	return __io_scm_file_account(ctx, file);
-}
-
 int io_register_files_update(struct io_ring_ctx *ctx, void __user *arg,
 			     unsigned nr_args);
 int io_register_rsrc_update(struct io_ring_ctx *ctx, void __user *arg,
-- 
2.43.0


[-- Attachment #10: 5.10-5.15-0002-io_uring-drop-any-code-related-to-SCM_RIGHTS.patch --]
[-- Type: text/x-patch, Size: 7401 bytes --]

From 63fcaffd0b3d0db784cbe3950549766936355e84 Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@kernel.dk>
Date: Wed, 13 Mar 2024 17:59:01 -0600
Subject: [PATCH 2/2] io_uring: drop any code related to SCM_RIGHTS

Commit 6e5e6d274956305f1fc0340522b38f5f5be74bdb upstream.

This is dead code after we dropped support for passing io_uring fds
over SCM_RIGHTS, get rid of it.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 io_uring/io_uring.c | 211 +-------------------------------------------
 1 file changed, 3 insertions(+), 208 deletions(-)

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 541e6a6985ec..386b32e6fd9a 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -62,7 +62,6 @@
 #include <linux/net.h>
 #include <net/sock.h>
 #include <net/af_unix.h>
-#include <net/scm.h>
 #include <linux/anon_inodes.h>
 #include <linux/sched/mm.h>
 #include <linux/uaccess.h>
@@ -440,9 +439,6 @@ struct io_ring_ctx {
 
 	/* Keep this last, we don't need it for the fast path */
 	struct {
-		#if defined(CONFIG_UNIX)
-			struct socket		*ring_sock;
-		#endif
 		/* hashed buffered write serialization */
 		struct io_wq_hash		*hash_map;
 
@@ -8151,15 +8147,6 @@ static void io_free_file_tables(struct io_file_table *table)
 
 static void __io_sqe_files_unregister(struct io_ring_ctx *ctx)
 {
-#if defined(CONFIG_UNIX)
-	if (ctx->ring_sock) {
-		struct sock *sock = ctx->ring_sock->sk;
-		struct sk_buff *skb;
-
-		while ((skb = skb_dequeue(&sock->sk_receive_queue)) != NULL)
-			kfree_skb(skb);
-	}
-#else
 	int i;
 
 	for (i = 0; i < ctx->nr_user_files; i++) {
@@ -8169,7 +8156,6 @@ static void __io_sqe_files_unregister(struct io_ring_ctx *ctx)
 		if (file)
 			fput(file);
 	}
-#endif
 	io_free_file_tables(&ctx->file_table);
 	io_rsrc_data_free(ctx->file_data);
 	ctx->file_data = NULL;
@@ -8321,170 +8307,11 @@ static struct io_sq_data *io_get_sq_data(struct io_uring_params *p,
 	return sqd;
 }
 
-#if defined(CONFIG_UNIX)
-/*
- * Ensure the UNIX gc is aware of our file set, so we are certain that
- * the io_uring can be safely unregistered on process exit, even if we have
- * loops in the file referencing.
- */
-static int __io_sqe_files_scm(struct io_ring_ctx *ctx, int nr, int offset)
-{
-	struct sock *sk = ctx->ring_sock->sk;
-	struct scm_fp_list *fpl;
-	struct sk_buff *skb;
-	int i, nr_files;
-
-	fpl = kzalloc(sizeof(*fpl), GFP_KERNEL);
-	if (!fpl)
-		return -ENOMEM;
-
-	skb = alloc_skb(0, GFP_KERNEL);
-	if (!skb) {
-		kfree(fpl);
-		return -ENOMEM;
-	}
-
-	skb->sk = sk;
-	skb->scm_io_uring = 1;
-
-	nr_files = 0;
-	fpl->user = get_uid(current_user());
-	for (i = 0; i < nr; i++) {
-		struct file *file = io_file_from_index(ctx, i + offset);
-
-		if (!file)
-			continue;
-		fpl->fp[nr_files] = get_file(file);
-		unix_inflight(fpl->user, fpl->fp[nr_files]);
-		nr_files++;
-	}
-
-	if (nr_files) {
-		fpl->max = SCM_MAX_FD;
-		fpl->count = nr_files;
-		UNIXCB(skb).fp = fpl;
-		skb->destructor = unix_destruct_scm;
-		refcount_add(skb->truesize, &sk->sk_wmem_alloc);
-		skb_queue_head(&sk->sk_receive_queue, skb);
-
-		for (i = 0; i < nr; i++) {
-			struct file *file = io_file_from_index(ctx, i + offset);
-
-			if (file)
-				fput(file);
-		}
-	} else {
-		kfree_skb(skb);
-		free_uid(fpl->user);
-		kfree(fpl);
-	}
-
-	return 0;
-}
-
-/*
- * If UNIX sockets are enabled, fd passing can cause a reference cycle which
- * causes regular reference counting to break down. We rely on the UNIX
- * garbage collection to take care of this problem for us.
- */
-static int io_sqe_files_scm(struct io_ring_ctx *ctx)
-{
-	unsigned left, total;
-	int ret = 0;
-
-	total = 0;
-	left = ctx->nr_user_files;
-	while (left) {
-		unsigned this_files = min_t(unsigned, left, SCM_MAX_FD);
-
-		ret = __io_sqe_files_scm(ctx, this_files, total);
-		if (ret)
-			break;
-		left -= this_files;
-		total += this_files;
-	}
-
-	if (!ret)
-		return 0;
-
-	while (total < ctx->nr_user_files) {
-		struct file *file = io_file_from_index(ctx, total);
-
-		if (file)
-			fput(file);
-		total++;
-	}
-
-	return ret;
-}
-#else
-static int io_sqe_files_scm(struct io_ring_ctx *ctx)
-{
-	return 0;
-}
-#endif
-
 static void io_rsrc_file_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc)
 {
 	struct file *file = prsrc->file;
-#if defined(CONFIG_UNIX)
-	struct sock *sock = ctx->ring_sock->sk;
-	struct sk_buff_head list, *head = &sock->sk_receive_queue;
-	struct sk_buff *skb;
-	int i;
 
-	__skb_queue_head_init(&list);
-
-	/*
-	 * Find the skb that holds this file in its SCM_RIGHTS. When found,
-	 * remove this entry and rearrange the file array.
-	 */
-	skb = skb_dequeue(head);
-	while (skb) {
-		struct scm_fp_list *fp;
-
-		fp = UNIXCB(skb).fp;
-		for (i = 0; i < fp->count; i++) {
-			int left;
-
-			if (fp->fp[i] != file)
-				continue;
-
-			unix_notinflight(fp->user, fp->fp[i]);
-			left = fp->count - 1 - i;
-			if (left) {
-				memmove(&fp->fp[i], &fp->fp[i + 1],
-						left * sizeof(struct file *));
-			}
-			fp->count--;
-			if (!fp->count) {
-				kfree_skb(skb);
-				skb = NULL;
-			} else {
-				__skb_queue_tail(&list, skb);
-			}
-			fput(file);
-			file = NULL;
-			break;
-		}
-
-		if (!file)
-			break;
-
-		__skb_queue_tail(&list, skb);
-
-		skb = skb_dequeue(head);
-	}
-
-	if (skb_peek(&list)) {
-		spin_lock_irq(&head->lock);
-		while ((skb = __skb_dequeue(&list)) != NULL)
-			__skb_queue_tail(head, skb);
-		spin_unlock_irq(&head->lock);
-	}
-#else
 	fput(file);
-#endif
 }
 
 static void __io_rsrc_put_work(struct io_rsrc_node *ref_node)
@@ -8595,12 +8422,6 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
 		io_fixed_file_set(io_fixed_file_slot(&ctx->file_table, i), file);
 	}
 
-	ret = io_sqe_files_scm(ctx);
-	if (ret) {
-		__io_sqe_files_unregister(ctx);
-		return ret;
-	}
-
 	io_rsrc_node_switch(ctx, NULL);
 	return ret;
 out_fput:
@@ -9557,12 +9378,6 @@ static void io_ring_ctx_free(struct io_ring_ctx *ctx)
 	WARN_ON_ONCE(!list_empty(&ctx->rsrc_ref_list));
 	WARN_ON_ONCE(!llist_empty(&ctx->rsrc_put_llist));
 
-#if defined(CONFIG_UNIX)
-	if (ctx->ring_sock) {
-		ctx->ring_sock->file = NULL; /* so that iput() is called */
-		sock_release(ctx->ring_sock);
-	}
-#endif
 	WARN_ON_ONCE(!list_empty(&ctx->ltimeout_list));
 
 	if (ctx->mm_account) {
@@ -10499,32 +10314,12 @@ static int io_uring_install_fd(struct io_ring_ctx *ctx, struct file *file)
 /*
  * Allocate an anonymous fd, this is what constitutes the application
  * visible backing of an io_uring instance. The application mmaps this
- * fd to gain access to the SQ/CQ ring details. If UNIX sockets are enabled,
- * we have to tie this fd to a socket for file garbage collection purposes.
+ * fd to gain access to the SQ/CQ ring details.
  */
 static struct file *io_uring_get_file(struct io_ring_ctx *ctx)
 {
-	struct file *file;
-#if defined(CONFIG_UNIX)
-	int ret;
-
-	ret = sock_create_kern(&init_net, PF_UNIX, SOCK_RAW, IPPROTO_IP,
-				&ctx->ring_sock);
-	if (ret)
-		return ERR_PTR(ret);
-#endif
-
-	file = anon_inode_getfile("[io_uring]", &io_uring_fops, ctx,
-					O_RDWR | O_CLOEXEC);
-#if defined(CONFIG_UNIX)
-	if (IS_ERR(file)) {
-		sock_release(ctx->ring_sock);
-		ctx->ring_sock = NULL;
-	} else {
-		ctx->ring_sock->file = file;
-	}
-#endif
-	return file;
+	return anon_inode_getfile("[io_uring]", &io_uring_fops, ctx,
+				  O_RDWR | O_CLOEXEC);
 }
 
 static int io_uring_create(unsigned entries, struct io_uring_params *p,
-- 
2.43.0


[-- Attachment #11: 5.10-5.15-0001-io_uring-unix-drop-usage-of-io_uring-socket.patch --]
[-- Type: text/x-patch, Size: 3582 bytes --]

From 7c36fae9614f48c971c458f3bb12b97d3414abab Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@kernel.dk>
Date: Wed, 13 Mar 2024 17:54:49 -0600
Subject: [PATCH 1/2] io_uring/unix: drop usage of io_uring socket

Commit a4104821ad651d8a0b374f0b2474c345bbb42f82 upstream.

Since we no longer allow sending io_uring fds over SCM_RIGHTS, move to
using io_is_uring_fops() to detect whether this is a io_uring fd or not.
With that done, kill off io_uring_get_socket() as nobody calls it
anymore.

This is in preparation to yanking out the rest of the core related to
unix gc with io_uring.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 include/linux/io_uring.h | 10 +++++-----
 io_uring/io_uring.c      | 18 +++++-------------
 net/core/scm.c           |  2 +-
 net/unix/scm.c           |  4 +---
 4 files changed, 12 insertions(+), 22 deletions(-)

diff --git a/include/linux/io_uring.h b/include/linux/io_uring.h
index 649a4d7c241b..55d09f594cd1 100644
--- a/include/linux/io_uring.h
+++ b/include/linux/io_uring.h
@@ -6,9 +6,9 @@
 #include <linux/xarray.h>
 
 #if defined(CONFIG_IO_URING)
-struct sock *io_uring_get_socket(struct file *file);
 void __io_uring_cancel(bool cancel_all);
 void __io_uring_free(struct task_struct *tsk);
+bool io_is_uring_fops(struct file *file);
 
 static inline void io_uring_files_cancel(void)
 {
@@ -26,10 +26,6 @@ static inline void io_uring_free(struct task_struct *tsk)
 		__io_uring_free(tsk);
 }
 #else
-static inline struct sock *io_uring_get_socket(struct file *file)
-{
-	return NULL;
-}
 static inline void io_uring_task_cancel(void)
 {
 }
@@ -39,6 +35,10 @@ static inline void io_uring_files_cancel(void)
 static inline void io_uring_free(struct task_struct *tsk)
 {
 }
+static inline bool io_is_uring_fops(struct file *file)
+{
+	return false;
+}
 #endif
 
 #endif
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 55fd6d98fe12..541e6a6985ec 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -1116,19 +1116,6 @@ static struct kmem_cache *req_cachep;
 
 static const struct file_operations io_uring_fops;
 
-struct sock *io_uring_get_socket(struct file *file)
-{
-#if defined(CONFIG_UNIX)
-	if (file->f_op == &io_uring_fops) {
-		struct io_ring_ctx *ctx = file->private_data;
-
-		return ctx->ring_sock->sk;
-	}
-#endif
-	return NULL;
-}
-EXPORT_SYMBOL(io_uring_get_socket);
-
 static inline void io_tw_lock(struct io_ring_ctx *ctx, bool *locked)
 {
 	if (!*locked) {
@@ -10445,6 +10432,11 @@ static const struct file_operations io_uring_fops = {
 #endif
 };
 
+bool io_is_uring_fops(struct file *file)
+{
+	return file->f_op == &io_uring_fops;
+}
+
 static int io_allocate_scq_urings(struct io_ring_ctx *ctx,
 				  struct io_uring_params *p)
 {
diff --git a/net/core/scm.c b/net/core/scm.c
index e762a4b8a1d2..a877c4ef4c25 100644
--- a/net/core/scm.c
+++ b/net/core/scm.c
@@ -105,7 +105,7 @@ static int scm_fp_copy(struct cmsghdr *cmsg, struct scm_fp_list **fplp)
 		if (fd < 0 || !(file = fget_raw(fd)))
 			return -EBADF;
 		/* don't allow io_uring files */
-		if (io_uring_get_socket(file)) {
+		if (io_is_uring_fops(file)) {
 			fput(file);
 			return -EINVAL;
 		}
diff --git a/net/unix/scm.c b/net/unix/scm.c
index e8e2a00bb0f5..d1048b4c2baa 100644
--- a/net/unix/scm.c
+++ b/net/unix/scm.c
@@ -34,10 +34,8 @@ struct sock *unix_get_socket(struct file *filp)
 		/* PF_UNIX ? */
 		if (s && sock->ops && sock->ops->family == PF_UNIX)
 			u_sock = s;
-	} else {
-		/* Could be an io_uring instance */
-		u_sock = io_uring_get_socket(filp);
 	}
+
 	return u_sock;
 }
 EXPORT_SYMBOL(unix_get_socket);
-- 
2.43.0

Re: [PATCH 5.10/5.15] io_uring: fix registered files leak

[Fedor Pchelkin]

On 24/03/13 06:40PM, Jens Axboe wrote:
> Hi,
> 
> OK, here they are. Two patches attached for every stable kernel, that
> gets rid of the remnants of the SCM related code:
> 
> 5.4
> 5.10 and 5.15 (same patches)
> 6.1
> 6.6
> 6.7
> 
> Would appreciate if Fedor and Pavel could give them a once over, but I
> think they are all fine. It's just deleting the code...

Thank you, Jens!

FWIW, I think it's all good and it eliminates the reported problem
obviously. Compiled and tested the repro with my kernel config.

Just a minor notice - stable rules declare two common ways for upstream
patch mentioning in backports [1]. And the first one starts from
lowercase. No big deal here definitely but maybe somebody has some
handling of these two variants - by regexps or similar, I actually don't
know. But I see in the git history that Greg also applies the variant
you've used.

[1]: https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html#option-3

--
Fedor

Re: [PATCH 5.10/5.15] io_uring: fix registered files leak

[Jens Axboe]

On 3/14/24 9:55 AM, Fedor Pchelkin wrote:
> On 24/03/13 06:40PM, Jens Axboe wrote:
>> Hi,
>>
>> OK, here they are. Two patches attached for every stable kernel, that
>> gets rid of the remnants of the SCM related code:
>>
>> 5.4
>> 5.10 and 5.15 (same patches)
>> 6.1
>> 6.6
>> 6.7
>>
>> Would appreciate if Fedor and Pavel could give them a once over, but I
>> think they are all fine. It's just deleting the code...
> 
> Thank you, Jens!
> 
> FWIW, I think it's all good and it eliminates the reported problem
> obviously. Compiled and tested the repro with my kernel config.

Great, thanks for checking!

> Just a minor notice - stable rules declare two common ways for upstream
> patch mentioning in backports [1]. And the first one starts from
> lowercase. No big deal here definitely but maybe somebody has some
> handling of these two variants - by regexps or similar, I actually don't
> know. But I see in the git history that Greg also applies the variant
> you've used.

Honestly that doesn't matter, as long as the upstream commit is
referenced. I always do it this way, not my first stable rodeo.

-- 
Jens Axboe