{"id":"CVE-2026-98655","state":"PUBLISHED","title":"perf: Require kernel access for text poke events","description":"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 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.","publishedAt":"2026-10-18T15:44:05.722Z","updatedAt":"2026-10-30T12:38:27.085Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e17d43b93e544f5016c0251d2074c15568d5d963","status":"affected","lessThan":"4d8fc6290d14aa9e4c3b620fe3e5dc8ba3bea7e3","versionType":"git"},{"version":"e17d43b93e544f5016c0251d2074c15568d5d963","status":"affected","lessThan":"c30886396eb1c0e9fdc4296398dea0db0ab37610","versionType":"git"},{"version":"e17d43b93e544f5016c0251d2074c15568d5d963","status":"affected","lessThan":"0e26d44b7c64b045adebcf5d614140f811f09752","versionType":"git"},{"version":"e17d43b93e544f5016c0251d2074c15568d5d963","status":"affected","lessThan":"8c38cb055f6a9651198780e4e4d5283de4039f79","versionType":"git"},{"version":"e17d43b93e544f5016c0251d2074c15568d5d963","status":"affected","lessThan":"8473f44db9f710ea6f8cafb22f2e3ba6cb8ca9a7","versionType":"git"},{"version":"e17d43b93e544f5016c0251d2074c15568d5d963","status":"affected","lessThan":"e506333d1b9f42f1e402acebf1283af3c44a3809","versionType":"git"},{"version":"e17d43b93e544f5016c0251d2074c15568d5d963","status":"affected","lessThan":"677d0b51ac1a0db55d768c4c6399210b3de0795b","versionType":"git"},{"version":"e17d43b93e544f5016c0251d2074c15568d5d963","status":"affected","lessThan":"357e8a77a501d96c9517f01f4a211eed5e9c9184","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/events/core.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.9","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.9","versionType":"semver"},{"version":"5.10.273","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.224","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.113","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.56","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.10","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/events/core.c"]}],"references":["https://git.kernel.org/stable/c/4d8fc6290d14aa9e4c3b620fe3e5dc8ba3bea7e3","https://git.kernel.org/stable/c/c30886396eb1c0e9fdc4296398dea0db0ab37610","https://git.kernel.org/stable/c/0e26d44b7c64b045adebcf5d614140f811f09752","https://git.kernel.org/stable/c/8c38cb055f6a9651198780e4e4d5283de4039f79","https://git.kernel.org/stable/c/8473f44db9f710ea6f8cafb22f2e3ba6cb8ca9a7","https://git.kernel.org/stable/c/e506333d1b9f42f1e402acebf1283af3c44a3809","https://git.kernel.org/stable/c/677d0b51ac1a0db55d768c4c6399210b3de0795b","https://git.kernel.org/stable/c/357e8a77a501d96c9517f01f4a211eed5e9c9184"],"weaknesses":[],"ingestedAt":"2026-10-30T12:58:04.520Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/98xxx/CVE-2026-98655.json","commit":"1f312381e38164a43607eebab851b151dd16861e","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-98655","state":"PUBLISHED","datePublished":"2026-10-18T15:44:05.722Z","dateUpdated":"2026-10-30T12:38:27.085Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:25:14.362Z"},"containers":{"cna":{"title":"perf: Require kernel access for text poke events","descriptions":[{"lang":"en","value":"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 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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e17d43b93e544f5016c0251d2074c15568d5d963","status":"affected","lessThan":"4d8fc6290d14aa9e4c3b620fe3e5dc8ba3bea7e3","versionType":"git"},{"version":"e17d43b93e544f5016c0251d2074c15568d5d963","status":"affected","lessThan":"c30886396eb1c0e9fdc4296398dea0db0ab37610","versionType":"git"},{"version":"e17d43b93e544f5016c0251d2074c15568d5d963","status":"affected","lessThan":"0e26d44b7c64b045adebcf5d614140f811f09752","versionType":"git"},{"version":"e17d43b93e544f5016c0251d2074c15568d5d963","status":"affected","lessThan":"8c38cb055f6a9651198780e4e4d5283de4039f79","versionType":"git"},{"version":"e17d43b93e544f5016c0251d2074c15568d5d963","status":"affected","lessThan":"8473f44db9f710ea6f8cafb22f2e3ba6cb8ca9a7","versionType":"git"},{"version":"e17d43b93e544f5016c0251d2074c15568d5d963","status":"affected","lessThan":"e506333d1b9f42f1e402acebf1283af3c44a3809","versionType":"git"},{"version":"e17d43b93e544f5016c0251d2074c15568d5d963","status":"affected","lessThan":"677d0b51ac1a0db55d768c4c6399210b3de0795b","versionType":"git"},{"version":"e17d43b93e544f5016c0251d2074c15568d5d963","status":"affected","lessThan":"357e8a77a501d96c9517f01f4a211eed5e9c9184","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/events/core.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.9","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.9","versionType":"semver"},{"version":"5.10.273","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.224","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.113","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.56","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.10","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/events/core.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/4d8fc6290d14aa9e4c3b620fe3e5dc8ba3bea7e3"},{"url":"https://git.kernel.org/stable/c/c30886396eb1c0e9fdc4296398dea0db0ab37610"},{"url":"https://git.kernel.org/stable/c/0e26d44b7c64b045adebcf5d614140f811f09752"},{"url":"https://git.kernel.org/stable/c/8c38cb055f6a9651198780e4e4d5283de4039f79"},{"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"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-30T12:38:27.085Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.9","versionEndExcluding":"5.10.273"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.9","versionEndExcluding":"5.15.224"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.9","versionEndExcluding":"6.1.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.9","versionEndExcluding":"6.6.160"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.9","versionEndExcluding":"6.12.113"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.9","versionEndExcluding":"6.18.56"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.9","versionEndExcluding":"7.2.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.9","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}