{"id":"CVE-2026-98655","title":"perf: Require kernel access for text poke events","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nperf: Require kernel access for text poke events\n\nPerf events with exclude_kernel=1 can be opened without kernel perf\naccess. However, exclude_kernel does not suppress …","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= e17d43b93e544f5016c0251d2074c15568d5d963 < 8473f44db9f710ea6f8cafb22f2e3ba6cb8ca9a7","Linux >= e17d43b93e544f5016c0251d2074c15568d5d963 < e506333d1b9f42f1e402acebf1283af3c44a3809","Linux >= e17d43b93e544f5016c0251d2074c15568d5d963 < 677d0b51ac1a0db55d768c4c6399210b3de0795b","Linux >= e17d43b93e544f5016c0251d2074c15568d5d963 < 357e8a77a501d96c9517f01f4a211eed5e9c9184","Linux 5.9"],"published":"2026-10-18","updated":"2026-10-18","sourceUpdated":"2026-10-18T15:44:05.722Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98655","references":[{"url":"https://git.kernel.org/stable/c/8473f44db9f710ea6f8cafb22f2e3ba6cb8ca9a7"},{"url":"https://git.kernel.org/stable/c/e506333d1b9f42f1e402acebf1283af3c44a3809"},{"url":"https://git.kernel.org/stable/c/677d0b51ac1a0db55d768c4c6399210b3de0795b"},{"url":"https://git.kernel.org/stable/c/357e8a77a501d96c9517f01f4a211eed5e9c9184"}],"tags":["cve.org"],"ingestedAt":"2026-10-18T16:47:32.537Z","slug":"CVE-2026-98655","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nperf: Require kernel access for text poke events\n\nPerf events with exclude_kernel=1 can be opened without kernel perf\naccess. However, exclude_kernel does not suppress text-poke sideband\nrecords. Every PERF_RECORD_TEXT_POKE is marked PERF_RECORD_MISC_KERNEL\nand contains a raw kernel instruction address.\n\nAn unprivileged task can therefore open and mmap a task-local software\nevent with text_poke=1. Both opening a count-only tracepoint event and\nconfiguring UDP GRO for ESP-in-UDP cause updates to inline static calls;\nthe observer receives the relocated addresses of the modified instructions.\nFor a known kernel image, any such address reveals the runtime kernel\ntext base despite KASLR.\n\nCall perf_allow_kernel() whenever attr.text_poke is set, regardless of\nexclude_kernel. Events that neither monitor kernel execution nor request\ntext-poke records retain their existing permissions.\n\n## Affected\n\n- `Linux >= e17d43b93e544f5016c0251d2074c15568d5d963 < 8473f44db9f710ea6f8cafb22f2e3ba6cb8ca9a7`\n- `Linux >= e17d43b93e544f5016c0251d2074c15568d5d963 < e506333d1b9f42f1e402acebf1283af3c44a3809`\n- `Linux >= e17d43b93e544f5016c0251d2074c15568d5d963 < 677d0b51ac1a0db55d768c4c6399210b3de0795b`\n- `Linux >= e17d43b93e544f5016c0251d2074c15568d5d963 < 357e8a77a501d96c9517f01f4a211eed5e9c9184`\n- `Linux 5.9`\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":[]}