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| author | Amir Goldstein <amir73il@gmail.com> | 2022-01-20 23:53:05 +0200 |
|---|---|---|
| committer | Jan Kara <jack@suse.cz> | 2022-01-24 14:17:02 +0100 |
| commit | 29044dae2e746949ad4b9cbdbfb248994d1dcdb4 (patch) | |
| tree | f7480a05b92c6d395836774ed3a52fb4bb5a3404 /fs/configfs | |
| parent | a37d9a17f099072fe4d3a9048b0321978707a918 (diff) | |
| download | lwn-29044dae2e746949ad4b9cbdbfb248994d1dcdb4.tar.gz lwn-29044dae2e746949ad4b9cbdbfb248994d1dcdb4.zip | |
fsnotify: fix fsnotify hooks in pseudo filesystems
Commit 49246466a989 ("fsnotify: move fsnotify_nameremove() hook out of
d_delete()") moved the fsnotify delete hook before d_delete() so fsnotify
will have access to a positive dentry.
This allowed a race where opening the deleted file via cached dentry
is now possible after receiving the IN_DELETE event.
To fix the regression in pseudo filesystems, convert d_delete() calls
to d_drop() (see commit 46c46f8df9aa ("devpts_pty_kill(): don't bother
with d_delete()") and move the fsnotify hook after d_drop().
Add a missing fsnotify_unlink() hook in nfsdfs that was found during
the audit of fsnotify hooks in pseudo filesystems.
Note that the fsnotify hooks in simple_recursive_removal() follow
d_invalidate(), so they require no change.
Link: https://lore.kernel.org/r/20220120215305.282577-2-amir73il@gmail.com
Reported-by: Ivan Delalande <colona@arista.com>
Link: https://lore.kernel.org/linux-fsdevel/YeNyzoDM5hP5LtGW@visor/
Fixes: 49246466a989 ("fsnotify: move fsnotify_nameremove() hook out of d_delete()")
Cc: stable@vger.kernel.org # v5.3+
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Diffstat (limited to 'fs/configfs')
| -rw-r--r-- | fs/configfs/dir.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c index 1466b5d01cbb..d3cd2a94d1e8 100644 --- a/fs/configfs/dir.c +++ b/fs/configfs/dir.c @@ -1780,8 +1780,8 @@ void configfs_unregister_group(struct config_group *group) configfs_detach_group(&group->cg_item); d_inode(dentry)->i_flags |= S_DEAD; dont_mount(dentry); + d_drop(dentry); fsnotify_rmdir(d_inode(parent), dentry); - d_delete(dentry); inode_unlock(d_inode(parent)); dput(dentry); @@ -1922,10 +1922,10 @@ void configfs_unregister_subsystem(struct configfs_subsystem *subsys) configfs_detach_group(&group->cg_item); d_inode(dentry)->i_flags |= S_DEAD; dont_mount(dentry); - fsnotify_rmdir(d_inode(root), dentry); inode_unlock(d_inode(dentry)); - d_delete(dentry); + d_drop(dentry); + fsnotify_rmdir(d_inode(root), dentry); inode_unlock(d_inode(root)); |