The Linux kernel's stmmac network driver had a vulnerability due to the RX path conversion to zero-copy, which omitted restoring NET_IP_ALIGN in the RX DMA offset. This omission caused IP headers to be misaligned on architectures like ARM32 where NET_IP_ALIGN equals 2. Misaligned IP headers cause fatal alignment exceptions and kernel panics when processing packets such as ICMP echo requests. The fix restores NET_IP_ALIGN in the RX offset, correcting the alignment and preventing the kernel panic. Previous attempts to fix alignment caused packet corruption and were reverted, but the current fix accounts properly for buffer sizes.

On affected systems, particularly ARM32 architectures, receiving certain network packets (e.g., ICMP echo requests) causes kernel panics due to alignment exceptions. This results in denial of service as the kernel crashes and restarts. There is no impact on confidentiality or integrity reported, only availability due to system crashes.

A fix is available that restores NET_IP_ALIGN in the RX DMA offset in the stmmac driver, correcting packet header alignment. Applying the official Linux kernel update that includes this fix will resolve the issue. No additional mitigation is required beyond applying the patch.