[src/trunk]: src/sys/net80211 Update the pointer after m_pullup, otherwise po...

[maxv <maxv%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/bb5eaca21db8
branches:  trunk
changeset: 358066:bb5eaca21db8
user:      maxv <maxv%NetBSD.org@localhost>
date:      Sun Dec 10 08:48:15 2017 +0000

description:
Update the pointer after m_pullup, otherwise possible use-after-free.

diffstat:

 sys/net80211/ieee80211_input.c |  6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diffs (27 lines):

diff -r 5ea52ed0807e -r bb5eaca21db8 sys/net80211/ieee80211_input.c
--- a/sys/net80211/ieee80211_input.c    Sun Dec 10 05:36:25 2017 +0000
+++ b/sys/net80211/ieee80211_input.c    Sun Dec 10 08:48:15 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ieee80211_input.c,v 1.89 2017/09/26 07:42:06 knakahara Exp $   */
+/*     $NetBSD: ieee80211_input.c,v 1.90 2017/12/10 08:48:15 maxv Exp $        */
 /*-
  * Copyright (c) 2001 Atsushi Onoe
  * Copyright (c) 2002-2005 Sam Leffler, Errno Consulting
@@ -36,7 +36,7 @@
 __FBSDID("$FreeBSD: src/sys/net80211/ieee80211_input.c,v 1.81 2005/08/10 16:22:29 sam Exp $");
 #endif
 #ifdef __NetBSD__
-__KERNEL_RCSID(0, "$NetBSD: ieee80211_input.c,v 1.89 2017/09/26 07:42:06 knakahara Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ieee80211_input.c,v 1.90 2017/12/10 08:48:15 maxv Exp $");
 #endif
 
 #ifdef _KERNEL_OPT
@@ -358,6 +358,8 @@
                        ic->ic_stats.is_rx_tooshort++;
                        goto out;               /* XXX */
                }
+               wh = mtod(m, struct ieee80211_frame *);
+
                switch (ic->ic_opmode) {
                case IEEE80211_M_STA:
                        if (dir != IEEE80211_FC1_DIR_FROMDS) {