On 04.06.21 18:11, Greg Kurz wrote:

As soon as fuse_dentry_automount() does up_write(&sb->s_umount), the
superblock can theoretically be killed. If this happens before the
submount was added to the &fc->mounts list, fuse_mount_remove() later
crashes in list_del_init() because it assumes the submount to be
already there.

Add the submount before dropping sb->s_umount to fix the inconsistency.
It is okay to nest fc->killsb under sb->s_umount, we already do this
on the ->kill_sb() path.

Signed-off-by: Greg Kurz <redacted>
---
  fs/fuse/dir.c | 8 ++++----
  1 file changed, 4 insertions(+), 4 deletions(-)

Reviewed-by: Max Reitz <redacted>