FreeBSD: vfsops: use setgen for error case

Fix from openzfs#12844 (comment) Reviewed-by: Brian Behlendorf <[email protected]> Reviewed-by: Alexander Motin <[email protected]> Reviewed-by: Ryan Moeller <[email protected]> Signed-off-by: Ahelenia Ziemiańska <[email protected]> Closes openzfs#12905
truenas · Jan 18, 2022 · c3620a3 · c3620a3
1 parent a0c70ee
commit c3620a3
Showing 1 changed file with 7 additions and 1 deletion.
diff --git a/module/os/freebsd/zfs/zfs_vfsops.c b/module/os/freebsd/zfs/zfs_vfsops.c
@@ -1823,6 +1823,7 @@ zfs_fhtovp(vfs_t *vfsp, fid_t *fidp, int flags, vnode_t **vpp)
 	vnode_t		*dvp;
 	uint64_t	object = 0;
 	uint64_t	fid_gen = 0;
+	uint64_t	setgen = 0;
 	uint64_t	gen_mask;
 	uint64_t	zp_gen;
 	int 		i, err;
@@ -1838,7 +1839,6 @@ zfs_fhtovp(vfs_t *vfsp, fid_t *fidp, int flags, vnode_t **vpp)
 	if (zfsvfs->z_parent == zfsvfs && fidp->fid_len == LONG_FID_LEN) {
 		zfid_long_t	*zlfid = (zfid_long_t *)fidp;
 		uint64_t	objsetid = 0;
-		uint64_t	setgen = 0;
 
 		for (i = 0; i < sizeof (zlfid->zf_setid); i++)
 			objsetid |= ((uint64_t)zlfid->zf_setid[i]) << (8 * i);
@@ -1867,6 +1867,12 @@ zfs_fhtovp(vfs_t *vfsp, fid_t *fidp, int flags, vnode_t **vpp)
 		return (SET_ERROR(EINVAL));
 	}
 
+	if (fidp->fid_len == LONG_FID_LEN && (fid_gen > 1 || setgen != 0)) {
+		dprintf("snapdir fid: fid_gen (%llu) and setgen (%llu)\n",
+		    (u_longlong_t)fid_gen, (u_longlong_t)setgen);
+		return (SET_ERROR(EINVAL));
+	}
+
 	/*
 	 * A zero fid_gen means we are in .zfs or the .zfs/snapshot
 	 * directory tree. If the object == zfsvfs->z_shares_dir, then