linux-kernel - [PATCH] mISDN: prevent possible NULL pointer dereference

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <1455725996-10538-1-git-send-email-a.s.protopopov@gmail.com>
Date:	Wed, 17 Feb 2016 11:19:56 -0500
From:	Anton Protopopov <a.s.protopopov@...il.com>
To:	Karsten Keil <isdn@...ux-pingi.de>, netdev@...r.kernel.org,
	linux-kernel@...r.kernel.org
Cc:	Anton Protopopov <a.s.protopopov@...il.com>
Subject: [PATCH] mISDN: prevent possible NULL pointer dereference

A return value of the bchannel_get_rxbuf() function is compared with the
positive ENOMEM value instead of the negative -ENOMEM value to detect a
memory allocation problem. Thus, after a possible memory allocation
failure the bc->bch.rx_skb will be NULL which will lead to a NULL
pointer dereference.

Signed-off-by: Anton Protopopov <a.s.protopopov@...il.com>
---
 drivers/isdn/hardware/mISDN/netjet.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/isdn/hardware/mISDN/netjet.c b/drivers/isdn/hardware/mISDN/netjet.c
index 8e29447..afde4ed 100644
--- a/drivers/isdn/hardware/mISDN/netjet.c
+++ b/drivers/isdn/hardware/mISDN/netjet.c
@@ -392,7 +392,7 @@ read_dma(struct tiger_ch *bc, u32 idx, int cnt)
 	}
 	stat = bchannel_get_rxbuf(&bc->bch, cnt);
 	/* only transparent use the count here, HDLC overun is detected later */
-	if (stat == ENOMEM) {
+	if (stat == -ENOMEM) {
 		pr_warning("%s.B%d: No memory for %d bytes\n",
 			   card->name, bc->bch.nr, cnt);
 		return;
-- 
2.6.5