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| author | Amir Goldstein <amir73il@gmail.com> | 2024-04-16 21:14:52 +0300 |
|---|---|---|
| committer | Jan Kara <jack@suse.cz> | 2024-04-17 15:06:50 +0200 |
| commit | 795bb82d12a16a4cee42845b0e4c7e3276574e5d (patch) | |
| tree | e82347600c4058d7e4c08ca42d7afd9af065405a /fs/notify | |
| parent | a5e57b4d370c6d320e5bfb0c919fe00aee29e039 (diff) | |
| download | lwn-795bb82d12a16a4cee42845b0e4c7e3276574e5d.tar.gz lwn-795bb82d12a16a4cee42845b0e4c7e3276574e5d.zip | |
fsnotify: fix UAF from FS_ERROR event on a shutting down filesystem
Protect against use after free when filesystem calls fsnotify_sb_error()
during fs shutdown.
Move freeing of sb->s_fsnotify_info to destroy_super_work(), because it
may be accessed from fs shutdown context.
Reported-by: syzbot+5e3f9b2a67b45f16d4e6@syzkaller.appspotmail.com
Suggested-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/linux-fsdevel/20240416173211.4lnmgctyo4jn5fha@quack3/
Fixes: 07a3b8d0bf72 ("fsnotify: lazy attach fsnotify_sb_info state to sb")
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Message-Id: <20240416181452.567070-1-amir73il@gmail.com>
Diffstat (limited to 'fs/notify')
| -rw-r--r-- | fs/notify/fsnotify.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c index 2ae965ef37e8..ff69ae24c4e8 100644 --- a/fs/notify/fsnotify.c +++ b/fs/notify/fsnotify.c @@ -103,7 +103,11 @@ void fsnotify_sb_delete(struct super_block *sb) WARN_ON(fsnotify_sb_has_priority_watchers(sb, FSNOTIFY_PRIO_CONTENT)); WARN_ON(fsnotify_sb_has_priority_watchers(sb, FSNOTIFY_PRIO_PRE_CONTENT)); - kfree(sbinfo); +} + +void fsnotify_sb_free(struct super_block *sb) +{ + kfree(sb->s_fsnotify_info); } /* |