We may fail to pin one of the marks in fsnotify_prepare_user_wait() when
dropping the srcu read lock, resulting in use after free at the next
iteration.
Solution is to store both marks in iter_info instead of just the one we'll
be sending the event for.
Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
Fixes: 9385a84d7e1f ("fsnotify: Pass fsnotify_iter_info into handle_event handler")
Cc: <stable@xxxxxxxxxxxxxxx> # v4.12
---
fs/notify/fsnotify.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
index 0c4583b61717..48ec61f4c4d5 100644
--- a/fs/notify/fsnotify.c
+++ b/fs/notify/fsnotify.c
@@ -336,6 +336,9 @@ int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_is,
vfsmount_group = vfsmount_mark->group;
}
+ iter_info.inode_mark = inode_mark;
+ iter_info.vfsmount_mark = vfsmount_mark;
+
if (inode_group && vfsmount_group) {
int cmp = fsnotify_compare_groups(inode_group,
vfsmount_group);
@@ -348,9 +351,6 @@ int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_is,
}
}
- iter_info.inode_mark = inode_mark;
- iter_info.vfsmount_mark = vfsmount_mark;
-
ret = send_to_group(to_tell, inode_mark, vfsmount_mark, mask,
data, data_is, cookie, file_name,
&iter_info);
--
2.5.5
