{"id":"CVE-2026-98626","summary":"bpf: Restrict CO-RE poisoning to relocatable instructions","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Restrict CO-RE poisoning to relocatable instructions\n\nCO-RE relocation records can name any instruction offset. When a\nrelocation cannot be resolved, bpf_core_patch_insn() currently poisons its\ntarget before checking whether that instruction is a valid relocation\ntarget. Malformed metadata can therefore replace jumps, calls, exits,\nregister-source arithmetic, or non-immediate loads instead of failing at\nthe relocation step.\n\nHandle poisoning only after the instruction has passed the same class and\noperand-form checks used for a resolved relocation. Route invalid forms\nthrough the existing diagnostic and return a hard error. Keep poisoning\nsupported instructions, including both halves of a plain ldimm64, so an\nunresolved relocation in dead code remains valid.\n\nExtend bpf_core_poison_insn() to poison both halves of ldimm64, and return\nits status directly from each validated instruction case. This avoids\nrouting the success path through a common label and leaves the helper free\nto report errors.\n\nThe shared relocation code applies this restriction to both libbpf and\nin-kernel CO-RE.","modified":"2026-10-20T02:30:27.109413849Z","published":"2026-10-18T15:19:47.832Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98626.json"},"references":[{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"},{"type":"WEB","url":"https://git.kernel.org/stable/c/2d7d04357c41aa49a5ac658fcc207439f2ad6456"},{"type":"WEB","url":"https://git.kernel.org/stable/c/394ae398337c5f87e567f6cd63b937fc2b2f6ddc"},{"type":"WEB","url":"https://git.kernel.org/stable/c/8e4cbcca1e0a2fc5e6c8edb68e0cf5f2587f9319"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a0b79cdfcf34b53c85bac2d3cf022fc1342eeca0"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a8c47e62d9aea2d47a09e06c1682c59c21b92449"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d3219c229d16900cef936adad28633c98946e432"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f2a24101e89dd0804e717da7c1bd6af513698aa2"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98626.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98626"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"d7a252708dbc950ca2064310217e8b9f85846e2f"},{"fixed":"a8c47e62d9aea2d47a09e06c1682c59c21b92449"},{"fixed":"d3219c229d16900cef936adad28633c98946e432"},{"fixed":"a0b79cdfcf34b53c85bac2d3cf022fc1342eeca0"},{"fixed":"f2a24101e89dd0804e717da7c1bd6af513698aa2"},{"fixed":"2d7d04357c41aa49a5ac658fcc207439f2ad6456"},{"fixed":"8e4cbcca1e0a2fc5e6c8edb68e0cf5f2587f9319"},{"fixed":"394ae398337c5f87e567f6cd63b937fc2b2f6ddc"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98626.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.6.0"},{"fixed":"5.15.222"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.189"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.158"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.112"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.55"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.9"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98626.json"}}],"schema_version":"1.9.0"}