svn commit: r309891 - head/sys/kern

[Edward Tomasz Napierala]

Author: trasz
Date: Mon Dec 12 15:22:21 2016
New Revision: 309891
URL: https://svnweb.freebsd.org/changeset/base/309891

Log:
  Avoid dereferencing NULL pointers in devtoname().  I've seen it panic,
  called from ufs_print() in DDB.
  
  MFC after:	1 month

Modified:
  head/sys/kern/kern_conf.c

Modified: head/sys/kern/kern_conf.c
==============================================================================
--- head/sys/kern/kern_conf.c	Mon Dec 12 15:17:56 2016	(r309890)
+++ head/sys/kern/kern_conf.c	Mon Dec 12 15:22:21 2016	(r309891)
@@ -1230,6 +1230,9 @@ const char *
 devtoname(struct cdev *dev)
 {
 
+	if (dev == NULL)
+		return (NULL);
+
 	return (dev->si_name);
 }