svn commit: r300612 - head/sys/dev/an

[Sean Bruno]

Author: sbruno
Date: Tue May 24 13:57:23 2016
New Revision: 300612
URL: https://svnweb.freebsd.org/changeset/base/300612

Log:
  Reject ioctl commands for FLSHGCHR and FLSHPCHR if the size is greater
  than sc->areq.  This is a bounds check to ensure we're not just cramming
  arbitrarily sized nonsense into the driver and overflowing the heap.
  
  PR:		209545
  Submitted by:	cturt at hardenedbsd.org
  MFC after:	2 weeks

Modified:
  head/sys/dev/an/if_an.c

Modified: head/sys/dev/an/if_an.c
==============================================================================
--- head/sys/dev/an/if_an.c	Tue May 24 13:57:23 2016	(r300611)
+++ head/sys/dev/an/if_an.c	Tue May 24 13:57:23 2016	(r300612)
@@ -3749,6 +3749,9 @@ flashcard(struct ifnet *ifp, struct airo
 			return ENOBUFS;
 		break;
 	case AIROFLSHGCHR:	/* Get char from aux */
+		if (l_ioctl->len > sizeof(sc->areq)) {
+			return -EINVAL;
+		}
 		AN_UNLOCK(sc);
 		status = copyin(l_ioctl->data, &sc->areq, l_ioctl->len);
 		AN_LOCK(sc);
@@ -3760,6 +3763,9 @@ flashcard(struct ifnet *ifp, struct airo
 		else
 			return -1;
 	case AIROFLSHPCHR:	/* Send char to card. */
+		if (l_ioctl->len > sizeof(sc->areq)) {
+			return -EINVAL;
+		}
 		AN_UNLOCK(sc);
 		status = copyin(l_ioctl->data, &sc->areq, l_ioctl->len);
 		AN_LOCK(sc);