[PATCH 3.18 14/29] 9p: fix multiple NULL-pointer-dereferences

From: Greg Kroah-Hartman
Date: Fri Sep 07 2018 - 17:44:00 EST


3.18-stable review patch. If anyone has any objections, please let me know.

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

From: Tomas Bortoli <tomasbortoli@xxxxxxxxx>

commit 10aa14527f458e9867cf3d2cc6b8cb0f6704448b upstream.

Added checks to prevent GPFs from raising.

Link: http://lkml.kernel.org/r/20180727110558.5479-1-tomasbortoli@xxxxxxxxx
Signed-off-by: Tomas Bortoli <tomasbortoli@xxxxxxxxx>
Reported-by: syzbot+1a262da37d3bead15c39@xxxxxxxxxxxxxxxxxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Dominique Martinet <dominique.martinet@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
net/9p/trans_fd.c | 5 ++++-
net/9p/trans_rdma.c | 3 +++
net/9p/trans_virtio.c | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)

--- 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
@@ -617,6 +617,9 @@ 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) &&