{"id":"CVE-2026-98627","title":"bpf: Preserve packet pointer class displacement in regsafe()","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Preserve packet pointer class displacement in regsafe()\n\nregsafe() maps packet pointer IDs between states and checks that each\ncurrent register range is a subset o…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 022ac075088366b62e130da5e1b200bc93a47191 < 091b40845bd3cf96791171ca95113e9184ccb596","Linux >= 022ac075088366b62e130da5e1b200bc93a47191 < fd16449a9b3b31a8f18944c2f0e29e4e218ca2cf","Linux 7.1"],"published":"2026-10-18","updated":"2026-10-18","sourceUpdated":"2026-10-18T15:19:48.952Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98627","references":[{"url":"https://git.kernel.org/stable/c/091b40845bd3cf96791171ca95113e9184ccb596"},{"url":"https://git.kernel.org/stable/c/fd16449a9b3b31a8f18944c2f0e29e4e218ca2cf"}],"tags":["cve.org"],"ingestedAt":"2026-10-18T15:45:12.236Z","slug":"CVE-2026-98627","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Preserve packet pointer class displacement in regsafe()\n\nregsafe() maps packet pointer IDs between states and checks that each\ncurrent register range is a subset of the corresponding explored\nregister range. It does not, however, preserve the displacement between\nregisters that share a packet pointer ID.\n\nThis is unsound because packet range is shared by ID. A bounds check on\none class member updates every member, and a later access can consume the\nrange through another member. Commit 022ac0750883 (\"bpf: use reg->var_off\ninstead of reg->off for pointers\") folded the fixed pointer offset into\nr64 and removed the old off equality check, so two individually narrower\nregisters can prune even when their displacement has changed. The\nexplored path can then license an out-of-bounds packet access on the\npruned path.\n\nRequire matching range bases for packet pointers with an ID. Together\nwith the existing ID mapping, this preserves the displacement between\nmembers of each packet-pointer class without adding per-ID state.\nPacket pointers without an ID remain unaffected.\n\n## Affected\n\n- `Linux >= 022ac075088366b62e130da5e1b200bc93a47191 < 091b40845bd3cf96791171ca95113e9184ccb596`\n- `Linux >= 022ac075088366b62e130da5e1b200bc93a47191 < fd16449a9b3b31a8f18944c2f0e29e4e218ca2cf`\n- `Linux 7.1`\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":[]}