An issue was discovered in can_can_gw_rcv in net/can/gw.c in the Linux kernel through 4.19.13. The CAN frame modification rules allow bitwise logical operations that can be also applied to the can_dlc field. Because of a missing check, the CAN drivers may write arbitrary content beyond the data registers in the CAN controller's I/O memory when processing can-gw manipulated outgoing frames. This is related to cgw_csum_xor_rel. Users with CAP_NET_ADMIN can exploit this vulnerability to cause a system crash (general protection fault).
Created kernel tracking bugs for this issue:
Affects: fedora-all [bug 1663730]