{"id":"CVE-2026-97953","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: stmmac: fix TX descriptor availability check for TSO traffic\n\nstmmac_tso_xmit() estimates the number of free TX descriptors required by\na TSO skb as:\n\n\t(skb->len -…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: stmmac: fix TX descriptor availability check for TSO traffic\n\nstmmac_tso_xmit() estimates the number of free TX descriptors required by\na TSO skb as:\n\n\t(skb->len -…","severity":"high","cvss":7,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H","vendor":"Linux","product":"Linux","affected":["Linux >= f748be531d7012c456b97f66091d86b3675c5fef < ffa6d2481bc1c87f822ecd626561484e4ee24cef","Linux >= f748be531d7012c456b97f66091d86b3675c5fef < c28175220f808c867d5618de8ecc6dbcc815c773","Linux >= f748be531d7012c456b97f66091d86b3675c5fef < 65820fc743eae322f7f94f6a64d07861211d4b21","Linux >= f748be531d7012c456b97f66091d86b3675c5fef < 5e38d732ec67a5b1f9a56e6c73add480c4b6030a","Linux 4.7"],"published":"2026-09-25","updated":"2026-09-25","sourceUpdated":"2026-09-25T15:18:02.970","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-97953","references":[{"url":"https://git.kernel.org/stable/c/5e38d732ec67a5b1f9a56e6c73add480c4b6030a","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/65820fc743eae322f7f94f6a64d07861211d4b21","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c28175220f808c867d5618de8ecc6dbcc815c773","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ffa6d2481bc1c87f822ecd626561484e4ee24cef","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-09-25T11:06:38.877Z","slug":"CVE-2026-97953","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnet: stmmac: fix TX descriptor availability check for TSO traffic\n\nstmmac_tso_xmit() estimates the number of free TX descriptors required by\na TSO skb as:\n\n\t(skb->len - proto_hdr_len) / TSO_MAX_BUFF_SIZE + 1\n\nwhich assumes the payload is split into TSO_MAX_BUFF_SIZE chunks. This\nunderestimates the descriptors actually consumed by stmmac_tso_allocator(),\nsince each fragment is mapped individually and so it needs at least one\ndescriptor regardless of its size. Moreover, one descriptor is used for\nthe L2/L3/L4 headers and, when the MSS changes, one more is consumed for\nthe MSS context descriptor.\nFor a highly fragmented TSO skb the check can therefore pass even when the\nring has too few free slots. stmmac_tso_allocator() then writes past the\navailable descriptors, overwriting descriptors still owned by the DMA\nengine, corrupting the TX ring.\nAdd stmmac_tso_get_num_desc() to compute the exact number of descriptors\nneeded for the header, the linear payload and each fragment, plus the MSS\ncontext descriptor when required, and use it in the availability check.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":38.5,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":210942,"id":"CVE-2026-97953","ts":1790349117626,"field":"cvss","old":null,"new":"7"},{"seq":210941,"id":"CVE-2026-97953","ts":1790349117626,"field":"severity","old":"none","new":"high"}]}