public inbox for [email protected]
 help / color / mirror / Atom feed
From: Stefan Roesch <[email protected]>
To: <[email protected]>, <[email protected]>,
	<[email protected]>, <[email protected]>,
	<[email protected]>
Cc: <[email protected]>, <[email protected]>, <[email protected]>,
	<[email protected]>, <[email protected]>, <[email protected]>,
	Christoph Hellwig <[email protected]>,
	Christian Brauner <[email protected]>
Subject: [PATCH v9 08/14] fs: add __remove_file_privs() with flags parameter
Date: Thu, 16 Jun 2022 14:22:15 -0700	[thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>

This adds the function __remove_file_privs, which allows the caller to
pass the kiocb flags parameter.

No intended functional changes in this patch.

Signed-off-by: Stefan Roesch <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Reviewed-by: Christian Brauner (Microsoft) <[email protected]>
---
 fs/inode.c | 57 +++++++++++++++++++++++++++++++++++-------------------
 1 file changed, 37 insertions(+), 20 deletions(-)

diff --git a/fs/inode.c b/fs/inode.c
index bd4da9c5207e..a2e18379c8a6 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -2010,36 +2010,43 @@ static int __remove_privs(struct user_namespace *mnt_userns,
 	return notify_change(mnt_userns, dentry, &newattrs, NULL);
 }
 
-/*
- * Remove special file priviledges (suid, capabilities) when file is written
- * to or truncated.
- */
-int file_remove_privs(struct file *file)
+static int __file_remove_privs(struct file *file, unsigned int flags)
 {
 	struct dentry *dentry = file_dentry(file);
 	struct inode *inode = file_inode(file);
+	int error;
 	int kill;
-	int error = 0;
 
-	/*
-	 * Fast path for nothing security related.
-	 * As well for non-regular files, e.g. blkdev inodes.
-	 * For example, blkdev_write_iter() might get here
-	 * trying to remove privs which it is not allowed to.
-	 */
 	if (IS_NOSEC(inode) || !S_ISREG(inode->i_mode))
 		return 0;
 
 	kill = dentry_needs_remove_privs(dentry);
-	if (kill < 0)
+	if (kill <= 0)
 		return kill;
-	if (kill)
-		error = __remove_privs(file_mnt_user_ns(file), dentry, kill);
+
+	if (flags & IOCB_NOWAIT)
+		return -EAGAIN;
+
+	error = __remove_privs(file_mnt_user_ns(file), dentry, kill);
 	if (!error)
 		inode_has_no_xattr(inode);
 
 	return error;
 }
+
+/**
+ * file_remove_privs - remove special file privileges (suid, capabilities)
+ * @file: file to remove privileges from
+ *
+ * When file is modified by a write or truncation ensure that special
+ * file privileges are removed.
+ *
+ * Return: 0 on success, negative errno on failure.
+ */
+int file_remove_privs(struct file *file)
+{
+	return __file_remove_privs(file, 0);
+}
 EXPORT_SYMBOL(file_remove_privs);
 
 /**
@@ -2090,18 +2097,28 @@ int file_update_time(struct file *file)
 }
 EXPORT_SYMBOL(file_update_time);
 
-/* Caller must hold the file's inode lock */
+/**
+ * file_modified - handle mandated vfs changes when modifying a file
+ * @file: file that was modified
+ *
+ * When file has been modified ensure that special
+ * file privileges are removed and time settings are updated.
+ *
+ * Context: Caller must hold the file's inode lock.
+ *
+ * Return: 0 on success, negative errno on failure.
+ */
 int file_modified(struct file *file)
 {
-	int err;
+	int ret;
 
 	/*
 	 * Clear the security bits if the process is not being run by root.
 	 * This keeps people from modifying setuid and setgid binaries.
 	 */
-	err = file_remove_privs(file);
-	if (err)
-		return err;
+	ret = __file_remove_privs(file, 0);
+	if (ret)
+		return ret;
 
 	if (unlikely(file->f_mode & FMODE_NOCMTIME))
 		return 0;
-- 
2.30.2




  parent reply	other threads:[~2022-06-16 21:38 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-06-16 21:22 [PATCH v9 00/14] io-uring/xfs: support async buffered writes Stefan Roesch
2022-06-16 21:22 ` [PATCH v9 01/14] mm: Move starting of background writeback into the main balancing loop Stefan Roesch
2022-06-16 21:22 ` [PATCH v9 02/14] mm: Move updates of dirty_exceeded into one place Stefan Roesch
2022-06-16 21:22 ` [PATCH v9 03/14] mm: Add balance_dirty_pages_ratelimited_flags() function Stefan Roesch
2022-06-16 21:22 ` [PATCH v9 04/14] iomap: Add flags parameter to iomap_page_create() Stefan Roesch
2022-06-16 21:22 ` [PATCH v9 05/14] iomap: Add async buffered write support Stefan Roesch
2022-06-16 21:22 ` [PATCH v9 06/14] iomap: Return -EAGAIN from iomap_write_iter() Stefan Roesch
2022-06-16 21:22 ` [PATCH v9 07/14] fs: Add check for async buffered writes to generic_write_checks Stefan Roesch
2022-06-16 21:22 ` Stefan Roesch [this message]
2022-06-16 21:22 ` [PATCH v9 09/14] fs: Split off inode_needs_update_time and __file_update_time Stefan Roesch
2022-06-16 21:22 ` [PATCH v9 10/14] fs: Add async write file modification handling Stefan Roesch
2022-06-16 21:22 ` [PATCH v9 11/14] io_uring: Add support for async buffered writes Stefan Roesch
2022-06-16 21:22 ` [PATCH v9 12/14] io_uring: Add tracepoint for short writes Stefan Roesch
2022-06-16 21:22 ` [PATCH v9 13/14] xfs: Specify lockmode when calling xfs_ilock_for_iomap() Stefan Roesch
2022-06-16 21:22 ` [PATCH v9 14/14] xfs: Add async buffered write support Stefan Roesch
2022-06-22 17:41 ` [PATCH v9 00/14] io-uring/xfs: support async buffered writes Jens Axboe
     [not found]   ` <[email protected]>
2022-06-22 19:37     ` Jens Axboe
2022-06-22 21:24   ` Jan Kara
2022-06-22 22:27 ` Jens Axboe
2022-06-23  0:29   ` Darrick J. Wong
2022-06-23  0:50     ` Jens Axboe

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox