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* [syzbot] KASAN: use-after-free Write in io_queue_worker_create
@ 2021-12-06  6:43 syzbot
  2021-12-06 17:28 ` Jens Axboe
  2021-12-10  5:21 ` syzbot
  0 siblings, 2 replies; 7+ messages in thread
From: syzbot @ 2021-12-06  6:43 UTC (permalink / raw)
  To: asml.silence, axboe, io-uring, linux-kernel, syzkaller-bugs

Hello,

syzbot found the following issue on:

HEAD commit:    944207047ca4 Merge tag 'usb-5.16-rc4' of git://git.kernel...
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13ebd129b00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=171728a464c05f2b
dashboard link: https://syzkaller.appspot.com/bug?extid=b60c982cb0efc5e05a47
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email protected]

==================================================================
BUG: KASAN: use-after-free in instrument_atomic_write include/linux/instrumented.h:86 [inline]
BUG: KASAN: use-after-free in clear_bit_unlock include/asm-generic/bitops/instrumented-lock.h:25 [inline]
BUG: KASAN: use-after-free in io_queue_worker_create+0x453/0x4e0 fs/io-wq.c:363
Write of size 8 at addr ffff888023e068d8 by task kworker/3:4/13798

CPU: 3 PID: 13798 Comm: kworker/3:4 Not tainted 5.16.0-rc3-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
Workqueue: events io_workqueue_create
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 print_address_description.constprop.0.cold+0x8d/0x2ed mm/kasan/report.c:247
 __kasan_report mm/kasan/report.c:433 [inline]
 kasan_report.cold+0x83/0xdf mm/kasan/report.c:450
 check_region_inline mm/kasan/generic.c:183 [inline]
 kasan_check_range+0x13d/0x180 mm/kasan/generic.c:189
 instrument_atomic_write include/linux/instrumented.h:86 [inline]
 clear_bit_unlock include/asm-generic/bitops/instrumented-lock.h:25 [inline]
 io_queue_worker_create+0x453/0x4e0 fs/io-wq.c:363
 io_workqueue_create+0x9e/0xe0 fs/io-wq.c:780
 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298
 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445
 kthread+0x405/0x4f0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>

Allocated by task 5554:
 kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 ____kasan_kmalloc mm/kasan/common.c:513 [inline]
 ____kasan_kmalloc mm/kasan/common.c:472 [inline]
 __kasan_kmalloc+0xa6/0xd0 mm/kasan/common.c:522
 kasan_kmalloc include/linux/kasan.h:269 [inline]
 kmem_cache_alloc_node_trace+0x208/0x5b0 mm/slab.c:3619
 kmalloc_node include/linux/slab.h:608 [inline]
 kzalloc_node include/linux/slab.h:735 [inline]
 create_io_worker+0x108/0x630 fs/io-wq.c:792
 io_wqe_create_worker fs/io-wq.c:300 [inline]
 io_wqe_enqueue+0x692/0xbc0 fs/io-wq.c:924
 io_queue_async_work+0x28b/0x5d0 fs/io_uring.c:1585
 io_queue_sqe_arm_apoll+0xcf/0x1a0 fs/io_uring.c:7004
 __io_queue_sqe fs/io_uring.c:7033 [inline]
 io_queue_sqe fs/io_uring.c:7060 [inline]
 io_submit_sqe fs/io_uring.c:7263 [inline]
 io_submit_sqes+0x796a/0x8a20 fs/io_uring.c:7369
 __do_sys_io_uring_enter+0xf6e/0x1f50 fs/io_uring.c:10070
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Freed by task 5554:
 kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38
 kasan_set_track+0x21/0x30 mm/kasan/common.c:46
 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370
 ____kasan_slab_free mm/kasan/common.c:366 [inline]
 ____kasan_slab_free mm/kasan/common.c:328 [inline]
 __kasan_slab_free+0xd1/0x110 mm/kasan/common.c:374
 kasan_slab_free include/linux/kasan.h:235 [inline]
 __cache_free mm/slab.c:3445 [inline]
 kfree+0x10d/0x2c0 mm/slab.c:3802
 create_worker_cont+0x3fb/0x550 fs/io-wq.c:766
 task_work_run+0xdd/0x1a0 kernel/task_work.c:164
 tracehook_notify_signal include/linux/tracehook.h:214 [inline]
 handle_signal_work kernel/entry/common.c:146 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
 exit_to_user_mode_prepare+0x256/0x290 kernel/entry/common.c:207
 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
 syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300
 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Last potentially related work creation:
 kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38
 __kasan_record_aux_stack+0xb5/0xe0 mm/kasan/generic.c:348
 task_work_add+0x3a/0x190 kernel/task_work.c:38
 io_queue_worker_create+0x3ee/0x4e0 fs/io-wq.c:362
 io_workqueue_create+0x9e/0xe0 fs/io-wq.c:780
 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298
 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445
 kthread+0x405/0x4f0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

Second to last potentially related work creation:
 kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38
 __kasan_record_aux_stack+0xb5/0xe0 mm/kasan/generic.c:348
 insert_work+0x48/0x370 kernel/workqueue.c:1354
 __queue_work+0x5ca/0xee0 kernel/workqueue.c:1520
 queue_work_on+0xee/0x110 kernel/workqueue.c:1547
 queue_work include/linux/workqueue.h:502 [inline]
 schedule_work include/linux/workqueue.h:563 [inline]
 create_worker_cont+0x44b/0x550 fs/io-wq.c:772
 task_work_run+0xdd/0x1a0 kernel/task_work.c:164
 tracehook_notify_signal include/linux/tracehook.h:214 [inline]
 handle_signal_work kernel/entry/common.c:146 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
 exit_to_user_mode_prepare+0x256/0x290 kernel/entry/common.c:207
 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
 syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300
 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae

The buggy address belongs to the object at ffff888023e06800
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 216 bytes inside of
 512-byte region [ffff888023e06800, ffff888023e06a00)
The buggy address belongs to the page:
page:ffffea00008f8180 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x23e06
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffffea00004f9bc8 ffffea000072de48 ffff888010c40600
raw: 0000000000000000 ffff888023e06000 0000000100000004 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x2c2220(__GFP_HIGH|__GFP_ATOMIC|__GFP_NOWARN|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_THISNODE), pid 10854, ts 2474866807743, free_ts 2469053292495
 prep_new_page mm/page_alloc.c:2418 [inline]
 get_page_from_freelist+0xa72/0x2f50 mm/page_alloc.c:4149
 __alloc_pages_slowpath.constprop.0+0x2eb/0x20d0 mm/page_alloc.c:4914
 __alloc_pages+0x412/0x500 mm/page_alloc.c:5382
 __alloc_pages_node include/linux/gfp.h:570 [inline]
 kmem_getpages mm/slab.c:1377 [inline]
 cache_grow_begin+0x75/0x470 mm/slab.c:2593
 cache_alloc_refill+0x27f/0x380 mm/slab.c:2965
 ____cache_alloc mm/slab.c:3048 [inline]
 ____cache_alloc mm/slab.c:3031 [inline]
 slab_alloc_node mm/slab.c:3249 [inline]
 kmem_cache_alloc_node_trace+0x49c/0x5b0 mm/slab.c:3617
 __do_kmalloc_node mm/slab.c:3639 [inline]
 __kmalloc_node_track_caller+0x38/0x60 mm/slab.c:3654
 kmalloc_reserve net/core/skbuff.c:354 [inline]
 __alloc_skb+0xde/0x340 net/core/skbuff.c:426
 skb_copy+0x137/0x2f0 net/core/skbuff.c:1586
 mac80211_hwsim_tx_frame_no_nl.isra.0+0xb17/0x1330 drivers/net/wireless/mac80211_hwsim.c:1565
 mac80211_hwsim_tx+0x574/0x12e0 drivers/net/wireless/mac80211_hwsim.c:1669
 drv_tx net/mac80211/driver-ops.h:35 [inline]
 ieee80211_tx_frags+0x552/0x970 net/mac80211/tx.c:1714
 __ieee80211_tx+0x145/0x4c0 net/mac80211/tx.c:1768
 ieee80211_tx+0x325/0x420 net/mac80211/tx.c:1948
 ieee80211_xmit+0x339/0x420 net/mac80211/tx.c:2040
 __ieee80211_subif_start_xmit+0x7ce/0xdc0 net/mac80211/tx.c:4248
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1338 [inline]
 free_pcp_prepare+0x374/0x870 mm/page_alloc.c:1389
 free_unref_page_prepare mm/page_alloc.c:3309 [inline]
 free_unref_page+0x19/0x690 mm/page_alloc.c:3388
 slab_destroy mm/slab.c:1627 [inline]
 slabs_destroy+0x89/0xc0 mm/slab.c:1647
 cache_flusharray mm/slab.c:3418 [inline]
 ___cache_free+0x4cc/0x610 mm/slab.c:3480
 qlink_free mm/kasan/quarantine.c:146 [inline]
 qlist_free_all+0x4e/0x110 mm/kasan/quarantine.c:165
 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:272
 __kasan_slab_alloc+0x97/0xb0 mm/kasan/common.c:444
 kasan_slab_alloc include/linux/kasan.h:259 [inline]
 slab_post_alloc_hook mm/slab.h:519 [inline]
 slab_alloc mm/slab.c:3323 [inline]
 kmem_cache_alloc+0x1bc/0x560 mm/slab.c:3507
 sock_alloc_inode+0x18/0x1c0 net/socket.c:303
 alloc_inode+0x61/0x230 fs/inode.c:235
 new_inode_pseudo+0x14/0xe0 fs/inode.c:944
 sock_alloc+0x3c/0x260 net/socket.c:626
 __sock_create+0xb9/0x790 net/socket.c:1428
 sock_create net/socket.c:1515 [inline]
 __sys_socket+0xef/0x200 net/socket.c:1557
 __do_sys_socket net/socket.c:1566 [inline]
 __se_sys_socket net/socket.c:1564 [inline]
 __x64_sys_socket+0x6f/0xb0 net/socket.c:1564
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80

Memory state around the buggy address:
 ffff888023e06780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888023e06800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888023e06880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                    ^
 ffff888023e06900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888023e06980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at [email protected].

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [syzbot] KASAN: use-after-free Write in io_queue_worker_create
  2021-12-06  6:43 [syzbot] KASAN: use-after-free Write in io_queue_worker_create syzbot
@ 2021-12-06 17:28 ` Jens Axboe
  2021-12-10  5:21 ` syzbot
  1 sibling, 0 replies; 7+ messages in thread
From: Jens Axboe @ 2021-12-06 17:28 UTC (permalink / raw)
  To: syzbot, asml.silence, io-uring, linux-kernel, syzkaller-bugs

On 12/5/21 11:43 PM, syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    944207047ca4 Merge tag 'usb-5.16-rc4' of git://git.kernel...
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=13ebd129b00000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=171728a464c05f2b
> dashboard link: https://syzkaller.appspot.com/bug?extid=b60c982cb0efc5e05a47
> compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> 
> Unfortunately, I don't have any reproducer for this issue yet.
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: [email protected]
> 
> ==================================================================
> BUG: KASAN: use-after-free in instrument_atomic_write include/linux/instrumented.h:86 [inline]
> BUG: KASAN: use-after-free in clear_bit_unlock include/asm-generic/bitops/instrumented-lock.h:25 [inline]
> BUG: KASAN: use-after-free in io_queue_worker_create+0x453/0x4e0 fs/io-wq.c:363
> Write of size 8 at addr ffff888023e068d8 by task kworker/3:4/13798

Looks like a spurious clear that can race with the task_work already ran and
the worker got dropped. Both handlers do clear it, so I think we just need:

diff --git a/fs/io-wq.c b/fs/io-wq.c
index 50cf9f92da36..35da9d90df76 100644
--- a/fs/io-wq.c
+++ b/fs/io-wq.c
@@ -359,10 +359,8 @@ static bool io_queue_worker_create(struct io_worker *worker,
 
 	init_task_work(&worker->create_work, func);
 	worker->create_index = acct->index;
-	if (!task_work_add(wq->task, &worker->create_work, TWA_SIGNAL)) {
-		clear_bit_unlock(0, &worker->create_state);
+	if (!task_work_add(wq->task, &worker->create_work, TWA_SIGNAL))
 		return true;
-	}
 	clear_bit_unlock(0, &worker->create_state);
 fail_release:
 	io_worker_release(worker);

-- 
Jens Axboe


^ permalink raw reply related	[flat|nested] 7+ messages in thread

* Re: [syzbot] KASAN: use-after-free Write in io_queue_worker_create
  2021-12-06  6:43 [syzbot] KASAN: use-after-free Write in io_queue_worker_create syzbot
  2021-12-06 17:28 ` Jens Axboe
@ 2021-12-10  5:21 ` syzbot
  2021-12-10  5:26   ` Jens Axboe
  1 sibling, 1 reply; 7+ messages in thread
From: syzbot @ 2021-12-10  5:21 UTC (permalink / raw)
  To: asml.silence, axboe, io-uring, linux-kernel, syzkaller-bugs

syzbot has found a reproducer for the following issue on:

HEAD commit:    c741e49150db Merge tag 'for-linus' of git://git.kernel.org..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=125600bab00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=221ffc09e39ebbd1
dashboard link: https://syzkaller.appspot.com/bug?extid=b60c982cb0efc5e05a47
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1686906db00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1539a9b9b00000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email protected]

==================================================================
BUG: KASAN: use-after-free in instrument_atomic_write include/linux/instrumented.h:86 [inline]
BUG: KASAN: use-after-free in clear_bit_unlock include/asm-generic/bitops/instrumented-lock.h:25 [inline]
BUG: KASAN: use-after-free in io_queue_worker_create+0x453/0x4e0 fs/io-wq.c:363
Write of size 8 at addr ffff88806e6920d8 by task kworker/1:1/25

CPU: 1 PID: 25 Comm: kworker/1:1 Not tainted 5.16.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events io_workqueue_create
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 print_address_description.constprop.0.cold+0x8d/0x320 mm/kasan/report.c:247
 __kasan_report mm/kasan/report.c:433 [inline]
 kasan_report.cold+0x83/0xdf mm/kasan/report.c:450
 check_region_inline mm/kasan/generic.c:183 [inline]
 kasan_check_range+0x13d/0x180 mm/kasan/generic.c:189
 instrument_atomic_write include/linux/instrumented.h:86 [inline]
 clear_bit_unlock include/asm-generic/bitops/instrumented-lock.h:25 [inline]
 io_queue_worker_create+0x453/0x4e0 fs/io-wq.c:363
 io_workqueue_create+0x9e/0xe0 fs/io-wq.c:780
 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298
 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445
 kthread+0x405/0x4f0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>

Allocated by task 4385:
 kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 ____kasan_kmalloc mm/kasan/common.c:513 [inline]
 ____kasan_kmalloc mm/kasan/common.c:472 [inline]
 __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:522
 kmalloc_node include/linux/slab.h:608 [inline]
 kzalloc_node include/linux/slab.h:735 [inline]
 create_io_worker+0x108/0x630 fs/io-wq.c:792
 create_worker_cb+0x202/0x270 fs/io-wq.c:329
 task_work_run+0xdd/0x1a0 kernel/task_work.c:164
 tracehook_notify_signal include/linux/tracehook.h:214 [inline]
 handle_signal_work kernel/entry/common.c:146 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
 exit_to_user_mode_prepare+0x256/0x290 kernel/entry/common.c:207
 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
 syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300
 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Freed by task 4385:
 kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38
 kasan_set_track+0x21/0x30 mm/kasan/common.c:46
 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370
 ____kasan_slab_free mm/kasan/common.c:366 [inline]
 ____kasan_slab_free mm/kasan/common.c:328 [inline]
 __kasan_slab_free+0xff/0x130 mm/kasan/common.c:374
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:1723 [inline]
 slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1749
 slab_free mm/slub.c:3513 [inline]
 kfree+0xf6/0x560 mm/slub.c:4561
 create_worker_cont+0x3fb/0x550 fs/io-wq.c:766
 task_work_run+0xdd/0x1a0 kernel/task_work.c:164
 tracehook_notify_signal include/linux/tracehook.h:214 [inline]
 handle_signal_work kernel/entry/common.c:146 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
 exit_to_user_mode_prepare+0x256/0x290 kernel/entry/common.c:207
 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
 syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300
 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Last potentially related work creation:
 kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38
 __kasan_record_aux_stack+0xf5/0x120 mm/kasan/generic.c:348
 task_work_add+0x3a/0x190 kernel/task_work.c:38
 io_queue_worker_create+0x3ee/0x4e0 fs/io-wq.c:362
 io_workqueue_create+0x9e/0xe0 fs/io-wq.c:780
 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298
 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445
 kthread+0x405/0x4f0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

Second to last potentially related work creation:
 kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38
 __kasan_record_aux_stack+0xf5/0x120 mm/kasan/generic.c:348
 insert_work+0x48/0x370 kernel/workqueue.c:1354
 __queue_work+0x5ca/0xee0 kernel/workqueue.c:1520
 queue_work_on+0xee/0x110 kernel/workqueue.c:1547
 queue_work include/linux/workqueue.h:502 [inline]
 schedule_work include/linux/workqueue.h:563 [inline]
 create_worker_cont+0x44b/0x550 fs/io-wq.c:772
 task_work_run+0xdd/0x1a0 kernel/task_work.c:164
 tracehook_notify_signal include/linux/tracehook.h:214 [inline]
 handle_signal_work kernel/entry/common.c:146 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
 exit_to_user_mode_prepare+0x256/0x290 kernel/entry/common.c:207
 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
 syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300
 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae

The buggy address belongs to the object at ffff88806e692000
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 216 bytes inside of
 512-byte region [ffff88806e692000, ffff88806e692200)
The buggy address belongs to the page:
page:ffffea0001b9a400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x6e690
head:ffffea0001b9a400 order:2 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 0000000000000000 dead000000000122 ffff888010c41c80
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 4385, ts 49566988561, free_ts 10514971018
 prep_new_page mm/page_alloc.c:2418 [inline]
 get_page_from_freelist+0xa72/0x2f50 mm/page_alloc.c:4149
 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5369
 __alloc_pages_node include/linux/gfp.h:570 [inline]
 alloc_slab_page mm/slub.c:1795 [inline]
 allocate_slab mm/slub.c:1930 [inline]
 new_slab+0xab/0x4a0 mm/slub.c:1993
 ___slab_alloc+0x918/0xfe0 mm/slub.c:3022
 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3109
 slab_alloc_node mm/slub.c:3200 [inline]
 kmem_cache_alloc_node_trace+0x116/0x310 mm/slub.c:3284
 kmalloc_node include/linux/slab.h:608 [inline]
 kzalloc_node include/linux/slab.h:735 [inline]
 create_io_worker+0x108/0x630 fs/io-wq.c:792
 create_worker_cb+0x202/0x270 fs/io-wq.c:329
 task_work_run+0xdd/0x1a0 kernel/task_work.c:164
 tracehook_notify_signal include/linux/tracehook.h:214 [inline]
 handle_signal_work kernel/entry/common.c:146 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
 exit_to_user_mode_prepare+0x256/0x290 kernel/entry/common.c:207
 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
 syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300
 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1338 [inline]
 free_pcp_prepare+0x374/0x870 mm/page_alloc.c:1389
 free_unref_page_prepare mm/page_alloc.c:3309 [inline]
 free_unref_page+0x19/0x690 mm/page_alloc.c:3388
 free_contig_range+0xa8/0xf0 mm/page_alloc.c:9271
 destroy_args+0xa8/0x646 mm/debug_vm_pgtable.c:1016
 debug_vm_pgtable+0x2984/0x2a16 mm/debug_vm_pgtable.c:1330
 do_one_initcall+0x103/0x650 init/main.c:1297
 do_initcall_level init/main.c:1370 [inline]
 do_initcalls init/main.c:1386 [inline]
 do_basic_setup init/main.c:1405 [inline]
 kernel_init_freeable+0x6b1/0x73a init/main.c:1610
 kernel_init+0x1a/0x1d0 init/main.c:1499
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

Memory state around the buggy address:
 ffff88806e691f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88806e692000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88806e692080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                    ^
 ffff88806e692100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88806e692180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [syzbot] KASAN: use-after-free Write in io_queue_worker_create
  2021-12-10  5:21 ` syzbot
@ 2021-12-10  5:26   ` Jens Axboe
  2021-12-10 11:00     ` syzbot
  0 siblings, 1 reply; 7+ messages in thread
From: Jens Axboe @ 2021-12-10  5:26 UTC (permalink / raw)
  To: syzbot, asml.silence, io-uring, linux-kernel, syzkaller-bugs

On 12/9/21 10:21 PM, syzbot wrote:
> syzbot has found a reproducer for the following issue on:
> 
> HEAD commit:    c741e49150db Merge tag 'for-linus' of git://git.kernel.org..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=125600bab00000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=221ffc09e39ebbd1
> dashboard link: https://syzkaller.appspot.com/bug?extid=b60c982cb0efc5e05a47
> compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1686906db00000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1539a9b9b00000
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: [email protected]

#syz test git://git.kernel.dk/linux-block io_uring-5.16

-- 
Jens Axboe


^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [syzbot] KASAN: use-after-free Write in io_queue_worker_create
  2021-12-10  5:26   ` Jens Axboe
@ 2021-12-10 11:00     ` syzbot
  2021-12-10 15:33       ` Jens Axboe
  0 siblings, 1 reply; 7+ messages in thread
From: syzbot @ 2021-12-10 11:00 UTC (permalink / raw)
  To: asml.silence, axboe, io-uring, linux-kernel, syzkaller-bugs

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
INFO: task hung in io_wq_put_and_exit

INFO: task syz-executor.2:8594 blocked for more than 143 seconds.
      Not tainted 5.16.0-rc1-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.2  state:D stack:26928 pid: 8594 ppid:  3894 flags:0x00024004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:4972 [inline]
 __schedule+0xa9a/0x4940 kernel/sched/core.c:6253
 schedule+0xd2/0x260 kernel/sched/core.c:6326
 schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1857
 do_wait_for_common kernel/sched/completion.c:85 [inline]
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion+0x174/0x270 kernel/sched/completion.c:138
 io_wq_exit_workers fs/io-wq.c:1222 [inline]
 io_wq_put_and_exit+0x33a/0xb70 fs/io-wq.c:1257
 io_uring_clean_tctx fs/io_uring.c:9803 [inline]
 io_uring_cancel_generic+0x622/0x695 fs/io_uring.c:9886
 io_uring_files_cancel include/linux/io_uring.h:16 [inline]
 do_exit+0x60c/0x2b40 kernel/exit.c:787
 do_group_exit+0x125/0x310 kernel/exit.c:929
 get_signal+0x47d/0x2220 kernel/signal.c:2830
 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:868
 handle_signal_work kernel/entry/common.c:148 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
 exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:207
 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
 syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300
 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fe940cbfb49
RSP: 002b:00007fe940435218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fe940dd2f68 RCX: 00007fe940cbfb49
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fe940dd2f68
RBP: 00007fe940dd2f60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe940dd2f6c
R13: 00007ffc1b1af90f R14: 00007fe940435300 R15: 0000000000022000
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8bb83a60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458
2 locks held by getty/3278:
 #0: ffff888023517098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:252
 #1: ffffc90002b962e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xcf0/0x1230 drivers/tty/n_tty.c:2113
2 locks held by kworker/u4:8/4544:
 #0: ffff8880b9d39a98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2b/0x120 kernel/sched/core.c:478
 #1: ffffc900038bfdb0 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2273

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.16.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
 watchdog+0xc1d/0xf50 kernel/hung_task.c:295
 kthread+0x405/0x4f0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4355 Comm: kworker/u4:7 Not tainted 5.16.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: phy12 ieee80211_iface_work
RIP: 0010:mark_lock+0x27/0x17b0 kernel/locking/lockdep.c:4566
Code: 00 00 90 41 57 41 56 41 55 41 54 41 89 d4 48 ba 00 00 00 00 00 fc ff df 55 53 48 81 ec 18 01 00 00 48 8d 5c 24 38 48 89 3c 24 <48> c7 44 24 38 b3 8a b5 41 48 c1 eb 03 48 c7 44 24 40 e0 66 37 8b
RSP: 0018:ffffc90002dbf380 EFLAGS: 00000082
RAX: 0000000000000004 RBX: ffffc90002dbf3b8 RCX: 1ffffffff1b228f1
RDX: dffffc0000000000 RSI: ffff88801d8fe160 RDI: ffff88801d8fd700
RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000001
R10: ffffffff817e2bc8 R11: 0000000000000000 R12: 0000000000000002
R13: dffffc0000000000 R14: ffff88801d8fe160 R15: 000000000003d510
FS:  0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055de5437a600 CR3: 000000000b88e000 CR4: 0000000000350ee0
Call Trace:
 <TASK>
 mark_held_locks+0x9f/0xe0 kernel/locking/lockdep.c:4206
 __trace_hardirqs_on_caller kernel/locking/lockdep.c:4224 [inline]
 lockdep_hardirqs_on_prepare kernel/locking/lockdep.c:4292 [inline]
 lockdep_hardirqs_on_prepare+0x135/0x400 kernel/locking/lockdep.c:4244
 trace_hardirqs_on+0x5b/0x1c0 kernel/trace/trace_preemptirq.c:49
 ___slab_alloc+0xc41/0xfe0 mm/slub.c:2978
 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3109
 slab_alloc_node mm/slub.c:3200 [inline]
 slab_alloc mm/slub.c:3242 [inline]
 __kmalloc+0x2fb/0x340 mm/slub.c:4419
 kmalloc include/linux/slab.h:595 [inline]
 kzalloc include/linux/slab.h:724 [inline]
 cfg80211_inform_single_bss_frame_data+0x302/0xee0 net/wireless/scan.c:2397
 cfg80211_inform_bss_frame_data+0xa7/0xb50 net/wireless/scan.c:2458
 ieee80211_bss_info_update+0x35b/0xb30 net/mac80211/scan.c:190
 ieee80211_rx_bss_info net/mac80211/ibss.c:1119 [inline]
 ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1610 [inline]
 ieee80211_ibss_rx_queued_mgmt+0x19cf/0x3130 net/mac80211/ibss.c:1639
 ieee80211_iface_process_skb net/mac80211/iface.c:1466 [inline]
 ieee80211_iface_work+0xa65/0xd00 net/mac80211/iface.c:1520
 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298
 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445
 kthread+0x405/0x4f0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
----------------
Code disassembly (best guess):
   0:	00 00                	add    %al,(%rax)
   2:	90                   	nop
   3:	41 57                	push   %r15
   5:	41 56                	push   %r14
   7:	41 55                	push   %r13
   9:	41 54                	push   %r12
   b:	41 89 d4             	mov    %edx,%r12d
   e:	48 ba 00 00 00 00 00 	movabs $0xdffffc0000000000,%rdx
  15:	fc ff df
  18:	55                   	push   %rbp
  19:	53                   	push   %rbx
  1a:	48 81 ec 18 01 00 00 	sub    $0x118,%rsp
  21:	48 8d 5c 24 38       	lea    0x38(%rsp),%rbx
  26:	48 89 3c 24          	mov    %rdi,(%rsp)
* 2a:	48 c7 44 24 38 b3 8a 	movq   $0x41b58ab3,0x38(%rsp) <-- trapping instruction
  31:	b5 41
  33:	48 c1 eb 03          	shr    $0x3,%rbx
  37:	48 c7 44 24 40 e0 66 	movq   $0xffffffff8b3766e0,0x40(%rsp)
  3e:	37 8b


Tested on:

commit:         02a3f9f3 io_uring: ensure task_work gets run as part o..
git tree:       git://git.kernel.dk/linux-block io_uring-5.16
console output: https://syzkaller.appspot.com/x/log.txt?x=1037614db00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=6d3b8fd1977c1e73
dashboard link: https://syzkaller.appspot.com/bug?extid=b60c982cb0efc5e05a47
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2


^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [syzbot] KASAN: use-after-free Write in io_queue_worker_create
  2021-12-10 11:00     ` syzbot
@ 2021-12-10 15:33       ` Jens Axboe
  2021-12-10 16:15         ` syzbot
  0 siblings, 1 reply; 7+ messages in thread
From: Jens Axboe @ 2021-12-10 15:33 UTC (permalink / raw)
  To: syzbot, asml.silence, io-uring, linux-kernel, syzkaller-bugs

On 12/10/21 4:00 AM, syzbot wrote:
> Hello,
> 
> syzbot has tested the proposed patch but the reproducer is still triggering an issue:
> INFO: task hung in io_wq_put_and_exit
> 
> INFO: task syz-executor.2:8594 blocked for more than 143 seconds.
>       Not tainted 5.16.0-rc1-syzkaller #0
> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> task:syz-executor.2  state:D stack:26928 pid: 8594 ppid:  3894 flags:0x00024004
> Call Trace:
>  <TASK>
>  context_switch kernel/sched/core.c:4972 [inline]
>  __schedule+0xa9a/0x4940 kernel/sched/core.c:6253
>  schedule+0xd2/0x260 kernel/sched/core.c:6326
>  schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1857
>  do_wait_for_common kernel/sched/completion.c:85 [inline]
>  __wait_for_common kernel/sched/completion.c:106 [inline]
>  wait_for_common kernel/sched/completion.c:117 [inline]
>  wait_for_completion+0x174/0x270 kernel/sched/completion.c:138
>  io_wq_exit_workers fs/io-wq.c:1222 [inline]
>  io_wq_put_and_exit+0x33a/0xb70 fs/io-wq.c:1257
>  io_uring_clean_tctx fs/io_uring.c:9803 [inline]
>  io_uring_cancel_generic+0x622/0x695 fs/io_uring.c:9886
>  io_uring_files_cancel include/linux/io_uring.h:16 [inline]
>  do_exit+0x60c/0x2b40 kernel/exit.c:787
>  do_group_exit+0x125/0x310 kernel/exit.c:929
>  get_signal+0x47d/0x2220 kernel/signal.c:2830
>  arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:868
>  handle_signal_work kernel/entry/common.c:148 [inline]
>  exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
>  exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:207
>  __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
>  syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300
>  do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
>  entry_SYSCALL_64_after_hwframe+0x44/0xae
> RIP: 0033:0x7fe940cbfb49
> RSP: 002b:00007fe940435218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
> RAX: fffffffffffffe00 RBX: 00007fe940dd2f68 RCX: 00007fe940cbfb49
> RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fe940dd2f68
> RBP: 00007fe940dd2f60 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe940dd2f6c
> R13: 00007ffc1b1af90f R14: 00007fe940435300 R15: 0000000000022000
>  </TASK>

#syz test git://git.kernel.dk/linux-block io_uring-5.16

-- 
Jens Axboe


^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [syzbot] KASAN: use-after-free Write in io_queue_worker_create
  2021-12-10 15:33       ` Jens Axboe
@ 2021-12-10 16:15         ` syzbot
  0 siblings, 0 replies; 7+ messages in thread
From: syzbot @ 2021-12-10 16:15 UTC (permalink / raw)
  To: asml.silence, axboe, io-uring, linux-kernel, syzkaller-bugs

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: [email protected]

Tested on:

commit:         263568d1 io-wq: check for wq exit after adding new wor..
git tree:       git://git.kernel.dk/linux-block io_uring-5.16
kernel config:  https://syzkaller.appspot.com/x/.config?x=6c3ab72998e7f1a4
dashboard link: https://syzkaller.appspot.com/bug?extid=b60c982cb0efc5e05a47
compiler:       Debian clang version 11.0.1-2, GNU ld (GNU Binutils for Debian) 2.35.2

Note: testing is done by a robot and is best-effort only.

^ permalink raw reply	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2021-12-10 16:15 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2021-12-06  6:43 [syzbot] KASAN: use-after-free Write in io_queue_worker_create syzbot
2021-12-06 17:28 ` Jens Axboe
2021-12-10  5:21 ` syzbot
2021-12-10  5:26   ` Jens Axboe
2021-12-10 11:00     ` syzbot
2021-12-10 15:33       ` Jens Axboe
2021-12-10 16:15         ` syzbot

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