{"id":"CVE-2026-99284","summary":"net: skbuff: propagate shared-frag marker in skb_zerocopy()","details":"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 not copy skb_shinfo(from)-\u003eflags into\nskb_shinfo(to)-\u003eflags.  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.","modified":"2026-11-10T12:12:12.842414678Z","published":"2026-11-07T20:40:33.661Z","related":["ALSA-2026:93412","ALSA-2026:93413","ALSA-2026:93436"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/99xxx/CVE-2026-99284.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/1a9c180cd8435917b7516edfb1c9148032c28773"},{"type":"WEB","url":"https://git.kernel.org/stable/c/1c623e3cbf43f12dd4a72712079bfa247a9b8ba3"},{"type":"WEB","url":"https://git.kernel.org/stable/c/79dc34beb1fdb3da79753e51e15c68591a2561fe"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d7d6ff98d5d1b400f02211f962ac32cc0020aeab"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/99xxx/CVE-2026-99284.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-99284"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"af2806f8f90a150160be898cd85332459c83c5cb"},{"fixed":"1c623e3cbf43f12dd4a72712079bfa247a9b8ba3"},{"fixed":"d7d6ff98d5d1b400f02211f962ac32cc0020aeab"},{"fixed":"1a9c180cd8435917b7516edfb1c9148032c28773"},{"fixed":"79dc34beb1fdb3da79753e51e15c68591a2561fe"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-99284.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.14.0"},{"fixed":"6.18.61"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.15"}]},{"type":"ECOSYSTEM","events":[{"introduced":"7.3.0"},{"fixed":"7.3.2"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-99284.json"}}],"schema_version":"1.9.2"}