[46/88] dlci: validate the net device in dlci_del()

Steven Rostedt
2013-08-13T15:58:55Z

[-- Attachment #1: 0046-dlci-validate-the-net-device-in-dlci_del.patch --]
[-- Type: text/plain, Size: 1918 bytes --]

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

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

From: Zefan Li <lizefan@huawei.com>

[ Upstream commit 578a1310f2592ba90c5674bca21c1dbd1adf3f0a ]

We triggered an oops while running trinity with 3.4 kernel:

BUG: unable to handle kernel paging request at 0000000100000d07
IP: [<ffffffffa0109738>] dlci_ioctl+0xd8/0x2d4 [dlci]
PGD 640c0d067 PUD 0
Oops: 0000 [#1] PREEMPT SMP
CPU 3
...
Pid: 7302, comm: trinity-child3 Not tainted 3.4.24.09+ 40 Huawei Technologies Co., Ltd. Tecal RH2285 /BC11BTSA
RIP: 0010:[<ffffffffa0109738>] [<ffffffffa0109738>] dlci_ioctl+0xd8/0x2d4 [dlci]
...
Call Trace:
[<ffffffff8137c5c3>] sock_ioctl+0x153/0x280
[<ffffffff81195494>] do_vfs_ioctl+0xa4/0x5e0
[<ffffffff8118354a>] ? fget_light+0x3ea/0x490
[<ffffffff81195a1f>] sys_ioctl+0x4f/0x80
[<ffffffff81478b69>] system_call_fastpath+0x16/0x1b
...

It's because the net device is not a dlci device.

Reported-by: Li Jinyue <lijinyue@huawei.com>
Signed-off-by: Li Zefan <lizefan@huawei.com>
Cc: stable@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
drivers/net/wan/dlci.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/drivers/net/wan/dlci.c b/drivers/net/wan/dlci.c
index 1f6e053..6a8a382 100644
--- a/drivers/net/wan/dlci.c
+++ b/drivers/net/wan/dlci.c
@@ -384,6 +384,7 @@ static int dlci_del(struct dlci_add *dlci)
struct frad_local *flp;
struct net_device *master, *slave;
int err;
+ bool found = false;

rtnl_lock();

@@ -394,6 +395,17 @@ static int dlci_del(struct dlci_add *dlci)
goto out;
}

+ list_for_each_entry(dlp, &dlci_devs, list) {
+ if (dlp->master == master) {
+ found = true;
+ break;
+ }
+ }
+ if (!found) {
+ err = -ENODEV;
+ goto out;
+ }
+
if (netif_running(master)) {
err = -EBUSY;
goto out;
--
1.7.10.4