CVE-2022-49863

In the Linux kernel, the following vulnerability has been resolved:

can: afcan: fix NULL pointer dereference in canrx_register()

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(__NRsocket, 0x1dul, 3ul, 1) to create CAN socket. (d) use syscall(NRbind, ...) to bind the bond device to CAN socket.

The bond device invokes the can-raw protocol registration interface to receive CAN packets. However, mlpriv is not allocated to the dev, devrcvlists is assigned to NULL in canrx_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:canrxregister+0x12d/0x1e0 Call Trace: <TASK> rawenablefilters+0x8d/0x120 rawenableallfilters+0x3b/0x130 raw_bind+0x118/0x4f0 __sys_bind+0x163/0x1a0 __x64sysbind+0x1e/0x30 dosyscall64+0x35/0x80 entrySYSCALL64afterhwframe+0x63/0xcd </TASK>