# CVE-2026-97953: net: stmmac: fix TX descriptor availability check for TSO traffic CVE-2026-97953 is fixed in 37 products on 1 platform, first by DEBIAN-CVE-2026-97953, released September 29, 2026. It is not reported as exploited. Patch Radar priority: High. - Web page: https://patchblox.com/security/cve/CVE-2026-97953 - Priority: High - CVSS: 7.8 (Moderate) - EPSS: 0.0041 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Sep 25, 2026 - Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-97953 ## 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. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | kernel-uek ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-core ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-core ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-core ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-core ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-devel ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-devel ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-core ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-core ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-deprecated ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-deprecated ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-desktop ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-desktop ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-extra ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-extra ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-extra-netfilter ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-extra-netfilter ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-usb ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-usb ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-wireless ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-wireless ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-devel ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-devel ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-doc ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-doc ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-core ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-core ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-deprecated ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-deprecated ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-desktop ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-desktop ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-extra ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-extra ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-extra-netfilter ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-extra-netfilter ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-usb ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-usb ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-wireless ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-wireless ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-tools ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-tools ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-core ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-core ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-devel ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-devel ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-core ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-core ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-deprecated ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-deprecated ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-desktop ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-desktop ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-extra ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-extra ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-extra-netfilter ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-extra-netfilter ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-usb ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-usb ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-wireless ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-wireless ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | linux Debian 13.5 (trixie) | 6.12.111-1 | [DEBIAN-CVE-2026-97953](https://patchblox.com/security/data/fix/linux/debian-cve-2026-97953.md) | Sep 29, 2026 | | Linux | linux Debian 14 | 7.2.7-1 | [DEBIAN-CVE-2026-97953](https://patchblox.com/security/data/fix/linux/debian-cve-2026-97953.md) | Sep 29, 2026 | | Linux | linux-6.12 Debian 12.15 (bookworm) | 6.12.111-1~deb12u1 | [DEBIAN-CVE-2026-97953](https://patchblox.com/security/data/fix/linux/debian-cve-2026-97953.md) | Sep 29, 2026 | --- Data as of 2026-11-09T01:18:40Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.