From: Matthew Dillon <dillon@apollo.backplane.com>
Date: Wed, 26 Dec 2018 06:17:25 +0000 (-0800)
Subject: iwm - Fix possible null pointer indirection
X-Git-Tag: v5.7.0~656
X-Git-Url: https://gitweb.dragonflybsd.org/dragonfly.git/commitdiff_plain/a0fed86142b3163a25e72eca99dd978a0fd91ed7

iwm - Fix possible null pointer indirection

* Fix possible null pointer indirection.  No known cases for dfly but
  I would speculate possibly something in the error path could
  trigger a NULL field there.

* Provisional change, may be adjusted in the future.  But harmless.

Taken-from: haiku
Requested-by: waddlespl
---

diff --git a/sys/dev/netif/iwm/if_iwm.c b/sys/dev/netif/iwm/if_iwm.c
index 6f869b181a..309ad6ad62 100644
--- a/sys/dev/netif/iwm/if_iwm.c
+++ b/sys/dev/netif/iwm/if_iwm.c
@@ -1040,7 +1040,8 @@ iwm_reset_rx_ring(struct iwm_softc *sc, struct iwm_rx_ring *ring)
 	 * The hw rx ring index in shared memory must also be cleared,
 	 * otherwise the discrepancy can cause reprocessing chaos.
 	 */
-	memset(sc->rxq.stat, 0, sizeof(*sc->rxq.stat));
+	if (sc->rxq.stat)
+		memset(sc->rxq.stat, 0, sizeof(*sc->rxq.stat));
 }
 
 static void