CVE-2026-45940
MediumCVSS 5.5Exploitation Probability (EPSS)
Low risk10th percentile - higher than 10% of all known CVEs
Summary
A vulnerability has been identified and resolved in the Linux kernel. The issue affects GMAC4, where in rare cases, with split header enabled, the hardware does not fill buf2 of the first descriptor with payload, leading to incorrect length calculations for buf2 of the second descriptor.
Risk Assessment
This vulnerability may lead to kernel crashes, resulting in system instability and potential service downtime. Organizations should be aware of the risks associated with improper data processing in the network.
Recommendation
It is recommended to update the Linux kernel to the latest version to mitigate this vulnerability and to monitor the system for any abnormal network handling behaviors.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: net: stmmac: fix oops when split header is enabled For GMAC4, when split header is enabled, in some rare cases, the hardware does not fill buf2 of the first descriptor with payload. Thus we cannot assume buf2 is always fully filled if it is not the last descriptor. Otherwise, the length of buf2 of the second descriptor will be calculated wrong and cause an oops: Unable to handle kernel paging request at virtual address ffff00019246bfc0 ... x2 : 0000000000000040 x1 : ffff00019246bfc0 x0 : ffff00009246c000 Call trace: dcache_inval_poc+0x28/0x58 (P) dma_direct_sync_single_for_cpu+0x38/0x6c __dma_sync_single_for_cpu+0x34/0x6c stmmac_napi_poll_rx+0x8f0/0xb60 __napi_poll.constprop.0+0x30/0x144 net_rx_action+0x160/0x274 handle_softirqs+0x1b8/0x1fc ... To fix this, the PL bit-field in RDES3 register is used for all descriptors, whether it is the last descriptor or not.