5.10-stable review patch. If anyone has any objections, please let me know.
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From: Gabriel Krisman Bertazi krisman@collabora.com
[ 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@collabora.com Suggested-by: Amir Goldstein amir73il@gmail.com Signed-off-by: Gabriel Krisman Bertazi krisman@collabora.com Reviewed-by: Amir Goldstein amir73il@gmail.com Reviewed-by: Jan Kara jack@suse.cz Signed-off-by: Jan Kara jack@suse.cz Signed-off-by: Chuck Lever chuck.lever@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 87d984e0cdc0c..8cd7d5d6955a0 100644 --- a/fs/nfsd/filecache.c +++ b/fs/nfsd/filecache.c @@ -601,6 +601,9 @@ 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 *