svn commit: r317092 - head/sys/boot/zfs

[Toomas Soome]

Author: tsoome
Date: Tue Apr 18 15:43:47 2017
New Revision: 317092
URL: https://svnweb.freebsd.org/changeset/base/317092

Log:
  loader: zfs reader vdev_probe should check for minimum device size
  
  The smallest device we can have in the pool is 64MB, since we are trying to
  walk all four labels to find the most up to date uberblock, this limit will
  also give us good method to check if we even should attempt to probe.
  
  Enforcing the check also will make sure we are not getting wrapped while
  calculating the label offset.
  
  Also, after label check, we should verify if we actually got any UB or not.
  
  PR:		218473
  Reported by:	Masachika ISHIZUKA
  Reviewed by:	allanjude
  Differential Revision:	https://reviews.freebsd.org/D10381

Modified:
  head/sys/boot/zfs/zfsimpl.c

Modified: head/sys/boot/zfs/zfsimpl.c
==============================================================================
--- head/sys/boot/zfs/zfsimpl.c	Tue Apr 18 15:36:13 2017	(r317091)
+++ head/sys/boot/zfs/zfsimpl.c	Tue Apr 18 15:43:47 2017	(r317092)
@@ -929,7 +929,7 @@ vdev_probe(vdev_phys_read_t *_read, void
 {
 	vdev_t vtmp;
 	vdev_phys_t *vdev_label = (vdev_phys_t *) zap_scratch;
-	vdev_phys_t *tmp_label = zfs_alloc(sizeof(vdev_phys_t));
+	vdev_phys_t *tmp_label;
 	spa_t *spa;
 	vdev_t *vdev, *top_vdev, *pool_vdev;
 	off_t off;
@@ -957,6 +957,12 @@ vdev_probe(vdev_phys_read_t *_read, void
 	psize = P2ALIGN(ldi_get_size(read_priv),
 	    (uint64_t)sizeof (vdev_label_t));
 
+	/* Test for minimum pool size. */
+	if (psize < SPA_MINDEVSIZE)
+		return (EIO);
+
+	tmp_label = zfs_alloc(sizeof(vdev_phys_t));
+
 	for (l = 0; l < VDEV_LABELS; l++) {
 		off = vdev_label_offset(psize, l,
 		    offsetof(vdev_label_t, vl_vdev_phys));
@@ -988,6 +994,9 @@ vdev_probe(vdev_phys_read_t *_read, void
 
 	zfs_free(tmp_label, sizeof (vdev_phys_t));
 
+	if (best_txg == 0)
+		return (EIO);
+
 	if (vdev_label->vp_nvlist[0] != NV_ENCODE_XDR)
 		return (EIO);