diff mbox series

[net,2/6] can: af_can: fix NULL pointer dereference in can_rx_register()

Message ID 20221107133217.59861-3-mkl@pengutronix.de (mailing list archive)
State Accepted
Commit 8aa59e355949442c408408c2d836e561794c40a1
Delegated to: Netdev Maintainers
Headers show
Series [net,1/6] can: af_can: can_exit(): add missing dev_remove_pack() of canxl_packet | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net
netdev/fixes_present success Fixes tag present in non-next series
netdev/subject_prefix success Link
netdev/cover_letter success Pull request is its own cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers fail 1 blamed authors not CCed: linux@rempel-privat.de; 4 maintainers not CCed: linux@rempel-privat.de socketcan@hartkopp.net pabeni@redhat.com edumazet@google.com
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 8 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Marc Kleine-Budde Nov. 7, 2022, 1:32 p.m. UTC 
From: Zhengchao Shao <shaozhengchao@huawei.com>

It causes NULL pointer dereference when testing as following:
(a) use syscall(__NR_socket, 0x10ul, 3ul, 0) to create netlink socket.
(b) use syscall(__NR_sendmsg, ...) to create bond link device and vxcan
    link device, and bind vxcan device to bond device (can also use
    ifenslave command to bind vxcan device to bond device).
(c) use syscall(__NR_socket, 0x1dul, 3ul, 1) to create CAN socket.
(d) use syscall(__NR_bind, ...) to bind the bond device to CAN socket.

The bond device invokes the can-raw protocol registration interface to
receive CAN packets. However, ml_priv is not allocated to the dev,
dev_rcv_lists is assigned to NULL in can_rx_register(). In this case,
it will occur the NULL pointer dereference issue.

The following is the stack information:
BUG: kernel NULL pointer dereference, address: 0000000000000008
PGD 122a4067 P4D 122a4067 PUD 1223c067 PMD 0
Oops: 0000 [#1] PREEMPT SMP
RIP: 0010:can_rx_register+0x12d/0x1e0
Call Trace:
<TASK>
raw_enable_filters+0x8d/0x120
raw_enable_allfilters+0x3b/0x130
raw_bind+0x118/0x4f0
__sys_bind+0x163/0x1a0
__x64_sys_bind+0x1e/0x30
do_syscall_64+0x35/0x80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
</TASK>

Fixes: 4e096a18867a ("net: introduce CAN specific pointer in the struct net_device")
Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Reviewed-by: Marc Kleine-Budde <mkl@pengutronix.de>
Link: https://lore.kernel.org/all/20221028085650.170470-1-shaozhengchao@huawei.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 net/can/af_can.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/net/can/af_can.c b/net/can/af_can.c
index 5e9e3e1e9825..27dcdcc0b808 100644
--- a/net/can/af_can.c
+++ b/net/can/af_can.c
@@ -450,7 +450,7 @@  int can_rx_register(struct net *net, struct net_device *dev, canid_t can_id,
 
 	/* insert new receiver  (dev,canid,mask) -> (func,data) */
 
-	if (dev && dev->type != ARPHRD_CAN)
+	if (dev && (dev->type != ARPHRD_CAN || !can_get_ml_priv(dev)))
 		return -ENODEV;
 
 	if (dev && !net_eq(net, dev_net(dev)))