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| author | Konstantin Belousov <kib@FreeBSD.org> | 2019-02-08 08:17:31 +0000 |
|---|---|---|
| committer | Konstantin Belousov <kib@FreeBSD.org> | 2019-02-08 08:17:31 +0000 |
| commit | 25728e8411704dc40ac2e46d79d8b44f0ae76f82 (patch) | |
| tree | 0eecb0d5cfbf3e68ba948cefdd9b58207e2b58c8 /sys/fs/nullfs | |
| parent | 930cc2dbef3d6493d5f7bd71a24386ad51c6884a (diff) | |
| download | src-25728e8411704dc40ac2e46d79d8b44f0ae76f82.tar.gz src-25728e8411704dc40ac2e46d79d8b44f0ae76f82.zip | |
Before using VTONULL(), check that the covered vnode belongs to nullfs.
Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Notes
Notes:
svn path=/head/; revision=343898
Diffstat (limited to 'sys/fs/nullfs')
| -rw-r--r-- | sys/fs/nullfs/null_vfsops.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/sys/fs/nullfs/null_vfsops.c b/sys/fs/nullfs/null_vfsops.c index d68d02991034..fdb5e9e7e7e0 100644 --- a/sys/fs/nullfs/null_vfsops.c +++ b/sys/fs/nullfs/null_vfsops.c @@ -145,10 +145,13 @@ nullfs_mount(struct mount *mp) /* * Check multi null mount to avoid `lock against myself' panic. */ - if (lowerrootvp == VTONULL(mp->mnt_vnodecovered)->null_lowervp) { - NULLFSDEBUG("nullfs_mount: multi null mount?\n"); - vput(lowerrootvp); - return (EDEADLK); + if (mp->mnt_vnodecovered->v_op == &null_vnodeops) { + nn = VTONULL(mp->mnt_vnodecovered); + if (nn == NULL || lowerrootvp == nn->null_lowervp) { + NULLFSDEBUG("nullfs_mount: multi null mount?\n"); + vput(lowerrootvp); + return (EDEADLK); + } } xmp = (struct null_mount *) malloc(sizeof(struct null_mount), |