On Wed, Oct 14, 2020 at 2:40 PM Andrii Nakryiko <andrii@xxxxxxxxxx> wrote: > > Fix data race in prepend_path() with re-reading mnt->mnt_ns twice without > holding the lock. is_mounted() does check for NULL, but is_anon_ns(mnt->mnt_ns) > might re-read the pointer again which could be NULL already, if in between > reads one of kern_unmount()/kern_unmount_array()/umount_tree() sets mnt->mnt_ns > to NULL. This seems like the obviously correct fix, so I think I'll just apply it directly. Al? Holler if you have any issues with this.. Linus