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,
        syzbot+1a262da37d3bead15c39@syzkaller.appspotmail.com,
        "Tomas Bortoli" <tomasbortoli@gmail.com>,
        "Dominique Martinet" <dominique.martinet@cea.fr>
Date:   Sun, 09 Dec 2018 21:50:33 +0000
Message-ID: <lsq.1544392233.602900197@decadent.org.uk>
Subject: [PATCH 3.16 131/328] 9p: fix multiple NULL-pointer-dereferences
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 10aa14527f458e9867cf3d2cc6b8cb0f6704448b upstream.

Added checks to prevent GPFs from raising.

Link: http://lkml.kernel.org/r/20180727110558.5479-1-tomasbortoli@gmail.com
Signed-off-by: Tomas Bortoli <tomasbortoli@gmail.com>
Reported-by: syzbot+1a262da37d3bead15c39@syzkaller.appspotmail.com
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
[bwh: Backported to 3.16:
 - Drop changes in trans_xen.c
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
--- a/net/9p/trans_fd.c
+++ b/net/9p/trans_fd.c
@@ -934,7 +934,7 @@ p9_fd_create_tcp(struct p9_client *clien
 	if (err < 0)
 		return err;
 
-	if (valid_ipaddr4(addr) < 0)
+	if (addr == NULL || valid_ipaddr4(addr) < 0)
 		return -EINVAL;
 
 	csocket = NULL;
@@ -982,6 +982,9 @@ p9_fd_create_unix(struct p9_client *clie
 
 	csocket = NULL;
 
+	if (addr == NULL)
+		return -EINVAL;
+
 	if (strlen(addr) >= UNIX_PATH_MAX) {
 		pr_err("%s (%d): address too long: %s\n",
 		       __func__, task_pid_nr(current), addr);
--- a/net/9p/trans_rdma.c
+++ b/net/9p/trans_rdma.c
@@ -623,6 +623,9 @@ rdma_create_trans(struct p9_client *clie
 	struct ib_qp_init_attr qp_attr;
 	struct ib_device_attr devattr;
 
+	if (addr == NULL)
+		return -EINVAL;
+
 	/* Parse the transport specific mount options */
 	err = parse_opts(args, &opts);
 	if (err < 0)
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -622,6 +622,9 @@ p9_virtio_create(struct p9_client *clien
 	int ret = -ENOENT;
 	int found = 0;
 
+	if (devname == NULL)
+		return -EINVAL;
+
 	mutex_lock(&virtio_9p_lock);
 	list_for_each_entry(chan, &virtio_chan_list, chan_list) {
 		if (!strncmp(devname, chan->tag, chan->tag_len) &&