{"id":"CVE-2026-99284","title":"net: skbuff: propagate shared-frag marker in skb_zerocopy()","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: skbuff: propagate shared-frag marker in skb_zerocopy()\n\nskb_zerocopy() moves frag descriptors from @from into @to and takes a\nreference on each frag, but it does n…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= af2806f8f90a150160be898cd85332459c83c5cb < 1c623e3cbf43f12dd4a72712079bfa247a9b8ba3","Linux >= af2806f8f90a150160be898cd85332459c83c5cb < d7d6ff98d5d1b400f02211f962ac32cc0020aeab","Linux >= af2806f8f90a150160be898cd85332459c83c5cb < 1a9c180cd8435917b7516edfb1c9148032c28773","Linux >= af2806f8f90a150160be898cd85332459c83c5cb < 79dc34beb1fdb3da79753e51e15c68591a2561fe","Linux 3.14"],"published":"2026-11-07","updated":"2026-11-07","sourceUpdated":"2026-11-07T20:40:33.661Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-99284","references":[{"url":"https://git.kernel.org/stable/c/1c623e3cbf43f12dd4a72712079bfa247a9b8ba3"},{"url":"https://git.kernel.org/stable/c/d7d6ff98d5d1b400f02211f962ac32cc0020aeab"},{"url":"https://git.kernel.org/stable/c/1a9c180cd8435917b7516edfb1c9148032c28773"},{"url":"https://git.kernel.org/stable/c/79dc34beb1fdb3da79753e51e15c68591a2561fe"}],"tags":["cve.org"],"ingestedAt":"2026-11-07T21:39:21.706Z","slug":"CVE-2026-99284","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnet: skbuff: propagate shared-frag marker in skb_zerocopy()\n\nskb_zerocopy() moves frag descriptors from @from into @to and takes a\nreference on each frag, but it does not copy skb_shinfo(from)->flags into\nskb_shinfo(to)->flags.  A destination skb holding the same page-cache\nbacked frags as the source therefore reports skb_has_shared_frag() as\nfalse.\n\nThat breaks the invariant relied on by later in-place writers.  ESP input\nchecks skb_has_shared_frag() before deciding whether an uncloned\nnonlinear skb can skip skb_cow_data(); with the marker lost, an skb that\nskb_zerocopy() built for nfnetlink_queue or for an openvswitch upcall is\ndecrypted in place, letting an unprivileged user write into the page\ncache of a root-owned read-only file.\n\nPropagate SKBFL_SHARED_FRAG when frag descriptors are copied, as done for\nthe other frag-transfer helpers.\n\n## Affected\n\n- `Linux >= af2806f8f90a150160be898cd85332459c83c5cb < 1c623e3cbf43f12dd4a72712079bfa247a9b8ba3`\n- `Linux >= af2806f8f90a150160be898cd85332459c83c5cb < d7d6ff98d5d1b400f02211f962ac32cc0020aeab`\n- `Linux >= af2806f8f90a150160be898cd85332459c83c5cb < 1a9c180cd8435917b7516edfb1c9148032c28773`\n- `Linux >= af2806f8f90a150160be898cd85332459c83c5cb < 79dc34beb1fdb3da79753e51e15c68591a2561fe`\n- `Linux 3.14`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}