diff options
| author | Konstantin Belousov <kib@FreeBSD.org> | 2026-05-16 22:16:45 +0000 |
|---|---|---|
| committer | Konstantin Belousov <kib@FreeBSD.org> | 2026-05-17 19:44:06 +0000 |
| commit | 7bdf2b5d5fbabfc8749c4ff6e618c3e843b14de0 (patch) | |
| tree | c8c769e95e2cd2938027ec30b53de540887bdc1c | |
| parent | 363ea40c765424b3cbd9b96790235af030fcc8ff (diff) | |
nullfs: do not allow to mount a vnode over itself
This causes recursion in VFS that is not worth handling.
PR: 275570
Reported by: Alex S <iwtcex@gmail.com>
Reviewed by: markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D57043
| -rw-r--r-- | sys/fs/nullfs/null_vfsops.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/sys/fs/nullfs/null_vfsops.c b/sys/fs/nullfs/null_vfsops.c index c3eec727aeea..0ec4f9c87297 100644 --- a/sys/fs/nullfs/null_vfsops.c +++ b/sys/fs/nullfs/null_vfsops.c @@ -152,6 +152,14 @@ nullfs_mount(struct mount *mp) lowerrootvp = ndp->ni_vp; /* + * Do not allow to mount a vnode over itself. + */ + if (mp->mnt_vnodecovered == lowerrootvp) { + vput(lowerrootvp); + return (EDEADLK); + } + + /* * Check multi null mount to avoid `lock against myself' panic. */ if (null_is_nullfs_vnode(mp->mnt_vnodecovered)) { |