Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Content-Type: text/plain; charset="UTF-8"
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
MIME-Version: 1.0
From:   Ben Hutchings <ben@decadent.org.uk>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
CC:     akpm@linux-foundation.org,
        "Tomas Bortoli" <tomasbortoli@gmail.com>,
        "Latchesar Ionkov" <lucho@ionkov.net>,
        "Ron Minnich" <rminnich@sandia.gov>,
        syzbot+65c6b72f284a39d416b4@syzkaller.appspotmail.com,
        "Jun Piao" <piaojun@huawei.com>,
        "Dominique Martinet" <dominique.martinet@cea.fr>,
        "Eric Van Hensbergen" <ericvh@gmail.com>,
        "Yiwen Jiang" <jiangyiwen@huawei.com>
Date:   Sun, 09 Dec 2018 21:50:33 +0000
Message-ID: <lsq.1544392233.892356241@decadent.org.uk>
Subject: [PATCH 3.16 127/328] net/9p/client.c: version pointer uninitialized
In-Reply-To: <lsq.1544392232.713909046@decadent.org.uk>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

3.16.62-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Tomas Bortoli <tomasbortoli@gmail.com>

commit 7913690dcc5e18e235769fd87c34143072f5dbea upstream.

The p9_client_version() does not initialize the version pointer. If the
call to p9pdu_readf() returns an error and version has not been allocated
in p9pdu_readf(), then the program will jump to the "error" label and will
try to free the version pointer. If version is not initialized, free()
will be called with uninitialized, garbage data and will provoke a crash.

Link: http://lkml.kernel.org/r/20180709222943.19503-1-tomasbortoli@gmail.com
Signed-off-by: Tomas Bortoli <tomasbortoli@gmail.com>
Reported-by: syzbot+65c6b72f284a39d416b4@syzkaller.appspotmail.com
Reviewed-by: Jun Piao <piaojun@huawei.com>
Reviewed-by: Yiwen Jiang <jiangyiwen@huawei.com>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@sandia.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
 net/9p/client.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -938,7 +938,7 @@ static int p9_client_version(struct p9_c
 {
 	int err = 0;
 	struct p9_req_t *req;
-	char *version;
+	char *version = NULL;
 	int msize;
 
 	p9_debug(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",