# CVE-2026-45940: net: stmmac: fix oops when split header is enabled CVE-2026-45940 is fixed in 16 products on 1 platform, first by DEBIAN-CVE-2026-45940, released May 27, 2026. It is not reported as exploited. Patch Radar priority: High. - Web page: https://patchblox.com/security/cve/CVE-2026-45940 - Priority: High - CVSS: 7.0 (Moderate) - EPSS: 0.0018 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: May 27, 2026 - Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45940 ## Description 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. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | dtb-aarch64 opensuse-leap 16.0 | 6.12.0-160000.36.1 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 | | Linux | kernel-64kb opensuse-leap 16.0 | 6.12.0-160000.36.1 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 | | Linux | kernel-64kb sles 15.7 | 6.4.0-150700.53.63.1 | [SUSE-SU-2026:2722-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2722-1.md) | Jul 1, 2026 | | Linux | kernel-64kb sles 16.0 | 6.12.0-160000.36.1 | [SUSE-SU-2026:22835-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22835-1.md) | Jul 21, 2026 | | Linux | kernel-azure opensuse-leap 16.0 | 6.12.0-160000.36.1 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 | | Linux | kernel-azure sles 15.7 | 6.4.0-150700.53.63.1 | [SUSE-SU-2026:2722-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2722-1.md) | Jul 1, 2026 | | Linux | kernel-azure sles 16.0 | 6.12.0-160000.36.1 | [SUSE-SU-2026:22835-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22835-1.md) | Jul 21, 2026 | | Linux | kernel-default opensuse-leap 16.0 | 6.12.0-160000.36.1 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 | | Linux | kernel-default sles 15.7 | 6.4.0-150700.53.63.1 | [SUSE-SU-2026:2722-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2722-1.md) | Jul 1, 2026 | | Linux | kernel-default sles 16.0 | 6.12.0-160000.36.1 | [SUSE-SU-2026:22835-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22835-1.md) | Jul 21, 2026 | | Linux | kernel-default-base opensuse-leap 16.0 | 6.12.0-160000.36.1.160000.2.17 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 | | Linux | kernel-default-base sles 15.7 | 6.4.0-150700.53.63.1.150700.17.37.1 | [SUSE-SU-2026:2722-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2722-1.md) | Jul 1, 2026 | | Linux | kernel-default-base sles 16.0 | 6.12.0-160000.36.1.160000.2.17 | [SUSE-SU-2026:22835-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22835-1.md) | Jul 21, 2026 | | Linux | kernel-docs opensuse-leap 16.0 | 6.12.0-160000.36.1 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 | | Linux | kernel-docs sles 15.7 | 6.4.0-150700.53.63.1 | [SUSE-SU-2026:2722-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2722-1.md) | Jul 1, 2026 | | Linux | kernel-docs sles 16.0 | 6.12.0-160000.36.1 | [SUSE-SU-2026:22835-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22835-1.md) | Jul 21, 2026 | | Linux | kernel-kvmsmall opensuse-leap 16.0 | 6.12.0-160000.36.1 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 | | Linux | kernel-kvmsmall sles 16.0 | 6.12.0-160000.36.1 | [SUSE-SU-2026:22835-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22835-1.md) | Jul 21, 2026 | | Linux | kernel-livepatch-SLE15-SP7-RT_Update_17 sles 15.7 | 1-150700.1.3.1 | [SUSE-SU-2026:2799-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2799-1.md) | Jul 8, 2026 | | Linux | kernel-livepatch-SLE15-SP7_Update_17 sles 15.7 | 1-150700.15.3.1 | [SUSE-SU-2026:2722-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2722-1.md) | Jul 1, 2026 | | Linux | kernel-obs-build opensuse-leap 16.0 | 6.12.0-160000.36.1 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 | | Linux | kernel-obs-build sles 15.7 | 6.4.0-150700.53.63.1 | [SUSE-SU-2026:2722-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2722-1.md) | Jul 1, 2026 | | Linux | kernel-obs-qa opensuse-leap 16.0 | 6.12.0-160000.36.1 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 | | Linux | kernel-obs-qa sles 16.0 | 6.12.0-160000.36.1 | [SUSE-SU-2026:22835-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22835-1.md) | Jul 21, 2026 | | Linux | kernel-rt opensuse-leap 16.0 | 6.12.0-160000.36.1 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 | | Linux | kernel-source opensuse-leap 16.0 | 6.12.0-160000.36.1 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 | | Linux | kernel-source sles 15.7 | 6.4.0-150700.53.63.1 | [SUSE-SU-2026:2722-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2722-1.md) | Jul 1, 2026 | | Linux | kernel-source sles 16.0 | 6.12.0-160000.36.1 | [SUSE-SU-2026:22835-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22835-1.md) | Jul 21, 2026 | | Linux | kernel-syms opensuse-leap 16.0 | 6.12.0-160000.36.1 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 | | Linux | kernel-syms sles 15.7 | 6.4.0-150700.53.63.1 | [SUSE-SU-2026:2722-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2722-1.md) | Jul 1, 2026 | | Linux | kernel-syms sles 16.0 | 6.12.0-160000.36.1 | [SUSE-SU-2026:22835-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22835-1.md) | Jul 21, 2026 | | Linux | kernel-zfcpdump opensuse-leap 16.0 | 6.12.0-160000.36.1 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 | | Linux | kernel-zfcpdump sles 15.7 | 6.4.0-150700.53.63.1 | [SUSE-SU-2026:2722-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2722-1.md) | Jul 1, 2026 | | Linux | kernel-zfcpdump sles 16.0 | 6.12.0-160000.36.1 | [SUSE-SU-2026:22835-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22835-1.md) | Jul 21, 2026 | | Linux | linux Debian 13.5 (trixie) | 6.12.115-2 | [DEBIAN-CVE-2026-45940](https://patchblox.com/security/data/fix/linux/debian-cve-2026-45940.md) | May 27, 2026 | | Linux | linux Debian 14 | 6.18.14-1 | [DEBIAN-CVE-2026-45940](https://patchblox.com/security/data/fix/linux/debian-cve-2026-45940.md) | May 27, 2026 | --- Data as of 2026-11-08T06:59:42Z UTC. 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