[PATCH 5.15 176/690] fsnotify: Protect fsnotify_handle_inode_event from no-inode events

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



5.15-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx>

[ Upstream commit 24dca90590509a7a6cbe0650100c90c5b8a3468a ]

FAN_FS_ERROR allows events without inodes - i.e. for file system-wide
errors.  Even though fsnotify_handle_inode_event is not currently used
by fanotify, this patch protects other backends from cases where neither
inode or dir are provided.  Also document the constraints of the
interface (inode and dir cannot be both NULL).

Link: https://lore.kernel.org/r/20211025192746.66445-12-krisman@xxxxxxxxxxxxx
Suggested-by: Amir Goldstein <amir73il@xxxxxxxxx>
Signed-off-by: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx>
Reviewed-by: Amir Goldstein <amir73il@xxxxxxxxx>
Reviewed-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
 fs/nfsd/filecache.c              | 3 +++
 fs/notify/fsnotify.c             | 3 +++
 include/linux/fsnotify_backend.h | 1 +
 3 files changed, 7 insertions(+)

diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index 1e8c31ed6c7c4..fbc0628c599af 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -595,6 +595,9 @@ nfsd_file_fsnotify_handle_event(struct fsnotify_mark *mark, u32 mask,
 				struct inode *inode, struct inode *dir,
 				const struct qstr *name, u32 cookie)
 {
+	if (WARN_ON_ONCE(!inode))
+		return 0;
+
 	trace_nfsd_file_fsnotify_handle_event(inode, mask);
 
 	/* Should be no marks on non-regular files */
diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
index fde3a1115a170..4034ca566f95c 100644
--- a/fs/notify/fsnotify.c
+++ b/fs/notify/fsnotify.c
@@ -252,6 +252,9 @@ static int fsnotify_handle_inode_event(struct fsnotify_group *group,
 	if (WARN_ON_ONCE(!ops->handle_inode_event))
 		return 0;
 
+	if (WARN_ON_ONCE(!inode && !dir))
+		return 0;
+
 	if ((inode_mark->mask & FS_EXCL_UNLINK) &&
 	    path && d_unlinked(path->dentry))
 		return 0;
diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
index 035438fe4a435..b71dc788018e4 100644
--- a/include/linux/fsnotify_backend.h
+++ b/include/linux/fsnotify_backend.h
@@ -136,6 +136,7 @@ struct mem_cgroup;
  * @dir:	optional directory associated with event -
  *		if @file_name is not NULL, this is the directory that
  *		@file_name is relative to.
+ *		Either @inode or @dir must be non-NULL.
  * @file_name:	optional file name associated with event
  * @cookie:	inotify rename cookie
  *
-- 
2.43.0







[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux