In the Linux kernel, the stmmac_tso_xmit() function failed to unmap DMA buffers when a fragment mapping failed, causing the linear part and previously mapped fragments to remain mapped. This also relates to the memory leak weakness CWE-401. The leak of DMA descriptors can exhaust kernel resources, potentially leading to network failure or a kernel panic. The underlying weaknesses are resource and memory leaks as defined by CWE-772 and CWE-401.

Linux kernel users who run the stmmac network driver before the stmmac_tso_xmit() fix. Any kernel version that includes the stmmac driver without the fixed DMA mapping release is affected. The issue is not vendor‑specific beyond the Linux kernel community; it impacts all distributions that ship the affected driver code.

The CVSS score is 5.5, indicating a medium severity. The EPSS score is <1%, suggesting a very low but non‑zero likelihood of exploitation. The vulnerability is not listed in the CISA KEV catalog. Because the bug causes a DMA mapping leak, repeated failures can drain system resources and lead to denial of service. The likely attack vector, inferred from the driver behavior, is sending crafted network traffic that forces a DMA mapping failure during packet transmission, thereby draining the mapping pool. No publicly disclosed exploit exists, but the kernel‑level nature of the defect and the high potential impact warrant careful monitoring.