can: m_can: m_can_{read_fifo,echo_tx_event}(): shift timestamp to full 32 bits

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: can: m_can: m_can_{read_fifo,echo_tx_event}(): shift timestamp to full 32 bits In commit 1be37d3b0414 ("can: m_can: fix periph RX path: use rx-offload to ensure skbs are sent from softirq context") the RX path for peripheral devices was switched to RX-offload. Received CAN frames are pushed to RX-offload together with a timestamp. RX-offload is designed to handle overflows of the timestamp correctly, if 32 bit timestamps are provided. The timestamps of m_can core are only 16 bits wide. So this patch shifts them to full 32 bit before passing them to RX-offload.

References

• https://git.kernel.org/stable/c/c7333f79888497bfd75dcd02a94eaf836dd1042c
• https://git.kernel.org/stable/c/2a2914a5bd7f38efe55a8372178146de82e0bce9
• https://git.kernel.org/stable/c/4c3333693f07313f5f0145a922f14a7d3c0f4f21