svn commit: r353757 - head/stand/libsa/zfs

[Toomas Soome]

Author: tsoome
Date: Sat Oct 19 08:08:06 2019
New Revision: 353757
URL: https://svnweb.freebsd.org/changeset/base/353757

Log:
  loader: zfs_fmtdev can crash when pool discovery did fail and we have no spa
  
  When zfs probe did fail and no spa was created, but zfs_fmtdev() is called,
  we will crash while dereferencing spa (NULL pointer dereference).
  
  MFC after:	1 week

Modified:
  head/stand/libsa/zfs/zfs.c

Modified: head/stand/libsa/zfs/zfs.c
==============================================================================
--- head/stand/libsa/zfs/zfs.c	Sat Oct 19 07:53:20 2019	(r353756)
+++ head/stand/libsa/zfs/zfs.c	Sat Oct 19 08:08:06 2019	(r353757)
@@ -769,11 +769,16 @@ zfs_fmtdev(void *vdev)
 	if (dev->dd.d_dev->dv_type != DEVT_ZFS)
 		return (buf);
 
-	if (dev->pool_guid == 0) {
-		spa = STAILQ_FIRST(&zfs_pools);
+	/* Do we have any pools? */
+	spa = STAILQ_FIRST(&zfs_pools);
+	if (spa == NULL)
+		return (buf);
+
+	if (dev->pool_guid == 0)
 		dev->pool_guid = spa->spa_guid;
-	} else
+	else
 		spa = spa_find_by_guid(dev->pool_guid);
+
 	if (spa == NULL) {
 		printf("ZFS: can't find pool by guid\n");
 		return (buf);