fanotify: fix copy_event_to_user() fid error clean up

[ Upstream commit f644bc449b37cc32d3ce7b36a88073873aa21bd5 ]

Ensure that clean up is performed on the allocated file descriptor and
struct file object in the event that an error is encountered while copying
fid info objects. Currently, we return directly to the caller when an error
is experienced in the fid info copying helper, which isn't ideal given that
the listener process could be left with a dangling file descriptor in their
fdtable.

Fixes: 5e469c830fdb ("fanotify: copy event fid info to user")
Fixes: 44d705b0370b ("fanotify: report name info for FAN_DIR_MODIFY event")
Link: https://lore.kernel.org/linux-fsdevel/YMKv1U7tNPK955ho@google.com/T/#m15361cd6399dad4396aad650de25dbf6b312288e
Link: https://lore.kernel.org/r/1ef8ae9100101eb1a91763c516c2e9a3a3b112bd.1623376346.git.repnop@google.com
Signed-off-by: Matthew Bobrowski <repnop@google.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index dcab112e1f0012073456c56b52b1ce4ac261d9a4..086b6bacbad176819cc0950a2f2bc0499eed49ec 100644 (file)
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -378,7 +378,7 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,
                                        info_type, fanotify_info_name(info),
                                        info->name_len, buf, count);
                if (ret < 0)
-                       return ret;
+                       goto out_close_fd;
 
                buf += ret;
                count -= ret;
@@ -426,7 +426,7 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,
                                        fanotify_event_object_fh(event),
                                        info_type, dot, dot_len, buf, count);
                if (ret < 0)
-                       return ret;
+                       goto out_close_fd;
 
                buf += ret;
                count -= ret;