From: Tilman Schmidt <tilman@imap.cc>
Date: Sun, 7 Jun 2009 09:09:24 +0000 (+0000)
Subject: isdn: prevent NULL ptr Oops in capi_cmsg2str()
X-Git-Tag: v3.0~8655^2~188
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=7d31acda9f8eaa27e2fd232712f7e1f3e9a79bdb;p=platform%2Fkernel%2Flinux-amlogic.git

isdn: prevent NULL ptr Oops in capi_cmsg2str()

The dereferencing of the private pointer cmsg->m in capi_cmsg2str() may
cause an Oops in case of an error, which is particularly inconvenient
as that function is typically used to format an error message. Add a
NULL pointer check to avoid this.

Impact: error handling improvement
Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/drivers/isdn/capi/capiutil.c b/drivers/isdn/capi/capiutil.c
index c7c2902..16f2e46 100644
--- a/drivers/isdn/capi/capiutil.c
+++ b/drivers/isdn/capi/capiutil.c
@@ -989,6 +989,8 @@ _cdebbuf *capi_cmsg2str(_cmsg * cmsg)
 {
 	_cdebbuf *cdb;
 
+	if (!cmsg->m)
+		return NULL;	/* no message */
 	cdb = cdebbuf_alloc();
 	if (!cdb)
 		return NULL;