[PATCH 3.16 131/328] 9p: fix multiple NULL-pointer-dereferences

Ben Hutchings
2018-12-09T22:14:24Z

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) &&