{"id":"CVE-2026-90051","title":"In the Linux kernel, the following vulnerability has been resolved:\n\ntcp: reject non zerocopy devmem tx\n\nDevmem tcp tx doesn't work without zero-copy, however it's not currently\nenforced if NETIF_F_SG isn't present","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\ntcp: reject non zerocopy devmem tx\n\nDevmem tcp tx doesn't work without zero-copy, however it's not currently\nenforced if NETIF_F_SG isn't present. In this case, tcp_sen…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","vendor":"Linux","product":"Linux","affected":["Linux >= bd61848900bff597764238f3a8ec67c815cd316e < 2151b2bcf6fcec52665f606eed20da068447f0b7","Linux >= bd61848900bff597764238f3a8ec67c815cd316e < b04326c7927af7048fd4e730f5770cca350d0a60","Linux >= bd61848900bff597764238f3a8ec67c815cd316e < 125755776bc6d4dd53eaf551c87e3d460625d638","Linux 6.16"],"published":"2026-09-17","updated":"2026-09-18","sourceUpdated":"2026-09-18T18:17:39.777","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-90051","references":[{"url":"https://git.kernel.org/stable/c/125755776bc6d4dd53eaf551c87e3d460625d638","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/2151b2bcf6fcec52665f606eed20da068447f0b7","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/b04326c7927af7048fd4e730f5770cca350d0a60","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"epss":0.00162,"epssPercentile":0.05782,"ingestedAt":"2026-09-17T16:21:47.904Z","slug":"CVE-2026-90051","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\ntcp: reject non zerocopy devmem tx\n\nDevmem tcp tx doesn't work without zero-copy, however it's not currently\nenforced if NETIF_F_SG isn't present. In this case, tcp_sendmsg_locked()\nwill try the copy path and try to copy data from an iovec which consists\nof offsets into the dma-buf and would normally fail. Moreover,\nd9c56501c72fd (\"net: tcp: block mixing readable and unreadable frags\")\nrelies on that and assumes that the devmem binding is present IFF we're\nusing the zero-copy path, which can be used to mix net-iov and pages in\na single skb, and break invariants. Let's reject devmem tx without\nzero-copy.\n\nNote, the parameter check the patch is modifying is too loose, we can\ncreate an io_uring request with dmabuf_id and all ZC flags, but which\nwon't have the binding. We replace it with stricter validation.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":207093,"id":"CVE-2026-90051","ts":1789757331234,"field":"cvss","old":null,"new":"7.8"},{"seq":207092,"id":"CVE-2026-90051","ts":1789757331234,"field":"severity","old":"none","new":"high"}]}