[src/trunk]: src/sys/dev/pci Null out sbuf->m on failure to avoid double-free...

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

details:   https://anonhg.NetBSD.org/src/rev/dab2eed27b4a
branches:  trunk
changeset: 825735:dab2eed27b4a
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Sat Jul 29 01:54:56 2017 +0000

description:
Null out sbuf->m on failure to avoid double-free later.

>From Ilja Van Sprundel.

Also null out sbuf->map out of paranoia.

diffstat:

 sys/dev/pci/if_ipw.c |  8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)

diffs (44 lines):

diff -r 6b8f175d6f88 -r dab2eed27b4a sys/dev/pci/if_ipw.c
--- a/sys/dev/pci/if_ipw.c      Sat Jul 29 01:47:48 2017 +0000
+++ b/sys/dev/pci/if_ipw.c      Sat Jul 29 01:54:56 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_ipw.c,v 1.64 2017/05/23 02:19:14 ozaki-r Exp $      */
+/*     $NetBSD: if_ipw.c,v 1.65 2017/07/29 01:54:56 riastradh Exp $    */
 /*     FreeBSD: src/sys/dev/ipw/if_ipw.c,v 1.15 2005/11/13 17:17:40 damien Exp         */
 
 /*-
@@ -29,7 +29,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_ipw.c,v 1.64 2017/05/23 02:19:14 ozaki-r Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_ipw.c,v 1.65 2017/07/29 01:54:56 riastradh Exp $");
 
 /*-
  * Intel(R) PRO/Wireless 2100 MiniPCI driver
@@ -607,6 +607,7 @@
                MCLGET(sbuf->m, M_DONTWAIT);
                if (!(sbuf->m->m_flags & M_EXT)) {
                        m_freem(sbuf->m);
+                       sbuf->m = NULL;
                        aprint_error_dev(sc->sc_dev, "could not allocate rx mbuf cluster\n");
                        error = ENOMEM;
                        goto fail;
@@ -619,6 +620,7 @@
                if (error != 0) {
                        aprint_error_dev(sc->sc_dev, "could not create rxbuf dma map\n");
                        m_freem(sbuf->m);
+                       sbuf->m = NULL;
                        goto fail;
                }
 
@@ -626,7 +628,9 @@
                    sbuf->m, BUS_DMA_READ | BUS_DMA_NOWAIT);
                if (error != 0) {
                        bus_dmamap_destroy(sc->sc_dmat, sbuf->map);
+                       sbuf->map = NULL;
                        m_freem(sbuf->m);
+                       sbuf->m = NULL;
                        aprint_error_dev(sc->sc_dev, "could not map rxbuf dma memory\n");
                        goto fail;
                }