{"id":"CVE-2026-98626","title":"bpf: Restrict CO-RE poisoning to relocatable instructions","summary":"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_patc…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= d7a252708dbc950ca2064310217e8b9f85846e2f < a8c47e62d9aea2d47a09e06c1682c59c21b92449","Linux >= d7a252708dbc950ca2064310217e8b9f85846e2f < d3219c229d16900cef936adad28633c98946e432","Linux >= d7a252708dbc950ca2064310217e8b9f85846e2f < a0b79cdfcf34b53c85bac2d3cf022fc1342eeca0","Linux >= d7a252708dbc950ca2064310217e8b9f85846e2f < f2a24101e89dd0804e717da7c1bd6af513698aa2","Linux >= d7a252708dbc950ca2064310217e8b9f85846e2f < 2d7d04357c41aa49a5ac658fcc207439f2ad6456","Linux >= d7a252708dbc950ca2064310217e8b9f85846e2f < 8e4cbcca1e0a2fc5e6c8edb68e0cf5f2587f9319","Linux >= d7a252708dbc950ca2064310217e8b9f85846e2f < 394ae398337c5f87e567f6cd63b937fc2b2f6ddc","Linux 5.6"],"published":"2026-10-18","updated":"2026-10-18","sourceUpdated":"2026-10-18T15:19:47.832Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98626","references":[{"url":"https://git.kernel.org/stable/c/a8c47e62d9aea2d47a09e06c1682c59c21b92449"},{"url":"https://git.kernel.org/stable/c/d3219c229d16900cef936adad28633c98946e432"},{"url":"https://git.kernel.org/stable/c/a0b79cdfcf34b53c85bac2d3cf022fc1342eeca0"},{"url":"https://git.kernel.org/stable/c/f2a24101e89dd0804e717da7c1bd6af513698aa2"},{"url":"https://git.kernel.org/stable/c/2d7d04357c41aa49a5ac658fcc207439f2ad6456"},{"url":"https://git.kernel.org/stable/c/8e4cbcca1e0a2fc5e6c8edb68e0cf5f2587f9319"},{"url":"https://git.kernel.org/stable/c/394ae398337c5f87e567f6cd63b937fc2b2f6ddc"}],"tags":["cve.org"],"ingestedAt":"2026-10-18T15:45:12.237Z","slug":"CVE-2026-98626","body":"## Overview\n\nIn 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.\n\n## Affected\n\n- `Linux >= d7a252708dbc950ca2064310217e8b9f85846e2f < a8c47e62d9aea2d47a09e06c1682c59c21b92449`\n- `Linux >= d7a252708dbc950ca2064310217e8b9f85846e2f < d3219c229d16900cef936adad28633c98946e432`\n- `Linux >= d7a252708dbc950ca2064310217e8b9f85846e2f < a0b79cdfcf34b53c85bac2d3cf022fc1342eeca0`\n- `Linux >= d7a252708dbc950ca2064310217e8b9f85846e2f < f2a24101e89dd0804e717da7c1bd6af513698aa2`\n- `Linux >= d7a252708dbc950ca2064310217e8b9f85846e2f < 2d7d04357c41aa49a5ac658fcc207439f2ad6456`\n- `Linux >= d7a252708dbc950ca2064310217e8b9f85846e2f < 8e4cbcca1e0a2fc5e6c8edb68e0cf5f2587f9319`\n- `Linux >= d7a252708dbc950ca2064310217e8b9f85846e2f < 394ae398337c5f87e567f6cd63b937fc2b2f6ddc`\n- `Linux 5.6`\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":[]}