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. An
unprivileged user can trigger a system crash (general protection fault).

 tyhicks> The original CVE description that states that an unprivileged user
  can trigger a system crash is incorrect. Only the root user, from the init
  namespace, can trigger the system crash. Therefore, we'll prioritize this
  issue as negligible.