CVE-2026-97953net: stmmac: fix TX descriptor availability check for TSO traffic
- 7.0HighCVSS base score
- 0.40%Exploitation in 30 daysEPSS · top 65% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: net: stmmac: fix TX descriptor availability check for TSO traffic stmmac_tso_xmit() estimates the number of free TX descriptors required by a TSO skb as: (skb->len - proto_hdr_len) / TSO_MAX_BUFF_SIZE + 1 which assumes the payload is split into TSO_MAX_BUFF_SIZE chunks. This underestimates the descriptors actually consumed by stmmac_tso_allocator(), since each fragment is mapped individually and so it needs at least one descriptor regardless of its size. Moreover, one descriptor is used for the L2/L3/L4 headers and, when the MSS changes, one more is consumed for the MSS context descriptor. For a highly fragmented TSO skb the check can therefore pass even when the ring has too few free slots. stmmac_tso_allocator() then writes past the available descriptors, overwriting descriptors still owned by the DMA engine, corrupting the TX ring. Add stmmac_tso_get_num_desc() to compute the exact number of descriptors needed for the header, the linear payload and each fragment, plus the MSS context descriptor when required, and use it in the availability check.
Timeline
ID reserved
By Linux
Published
- 26 days later
· 26 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High7.0 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H |
| NVDNVD · Received | 3.1 | High7.0 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H |
- EPSS (exploitation in 30 days)
- 0.40% · top 65% of all CVEs (15 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.0.
Affected products
- affected f748be531d7012c456b97f66091d86b3675c5fef – < 09c30547da2c45bb79f7d3adffc860af332c2d42
- affected f748be531d7012c456b97f66091d86b3675c5fef – < ffa6d2481bc1c87f822ecd626561484e4ee24cef
- affected f748be531d7012c456b97f66091d86b3675c5fef – < c28175220f808c867d5618de8ecc6dbcc815c773
- affected f748be531d7012c456b97f66091d86b3675c5fef – < 65820fc743eae322f7f94f6a64d07861211d4b21
- affected f748be531d7012c456b97f66091d86b3675c5fef – < 5e38d732ec67a5b1f9a56e6c73add480c4b6030a
- affected 4.7
- unaffected < 4.7
- unaffected 6.6.160 – ≤ 6.6.*
- unaffected 6.12.111 – ≤ 6.12.*
- unaffected 6.18.53 – ≤ 6.18.*
- unaffected 7.2.7 – ≤ 7.2.*
- unaffected 7.3 – ≤ *
References
References5
- https://git.kernel.org/stable/c/09c30547da2c45bb79f7d3adffc860af332c2d42 (opens in a new tab)
- https://git.kernel.org/stable/c/ffa6d2481bc1c87f822ecd626561484e4ee24cef (opens in a new tab)
- https://git.kernel.org/stable/c/c28175220f808c867d5618de8ecc6dbcc815c773 (opens in a new tab)
- https://git.kernel.org/stable/c/65820fc743eae322f7f94f6a64d07861211d4b21 (opens in a new tab)
- https://git.kernel.org/stable/c/5e38d732ec67a5b1f9a56e6c73add480c4b6030a (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-86807 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-97953)Record last updated .