{"id":"CVE-2026-99158","state":"PUBLISHED","title":"ring-buffer: Fix false warning in ring_buffer_map_get_reader()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nring-buffer: Fix false warning in ring_buffer_map_get_reader()\n\nThe mmap reader can warn when it catches up with a writer that is still\ncommitting events. rb_get_reader_page() returns NULL in this case, but\nring_buffer_map_get_reader() treats that result as an error.\n\nThe initial rb_per_cpu_empty() check filters out an empty buffer, but it\ndoes not guarantee that the next reader page has committed data. Writers\ndo not take reader_lock and can advance commit_page before publishing the\ncommitted length on the new page. rb_get_reader_page() can swap to that\npage, catch up with the writer and return NULL.\n\nHandle NULL through the existing no-data exit without warning. Remove the\ncaller's reader_page == commit_page check as well, since the reader-page\nhelper already handles that case. The existing metadata update and return\npath remain in place.","publishedAt":"2026-10-28T10:35:11.848Z","updatedAt":"2026-10-30T12:42:24.782Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"117c39200d9d760cbd5944bb89efb7b9c51965aa","status":"affected","lessThan":"32751946f9b3e502e3d6e42d98b343473112f887","versionType":"git"},{"version":"117c39200d9d760cbd5944bb89efb7b9c51965aa","status":"affected","lessThan":"029770f5badedc0f0ff85fc45e24785cbbee4a67","versionType":"git"},{"version":"117c39200d9d760cbd5944bb89efb7b9c51965aa","status":"affected","lessThan":"68e6ab180cfb6dfa79652f41ed7899a6d4cf5438","versionType":"git"},{"version":"117c39200d9d760cbd5944bb89efb7b9c51965aa","status":"affected","lessThan":"89bab1dba8a0167ef0d819e0f55b6bafa038e87f","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/trace/ring_buffer.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.10","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.10","versionType":"semver"},{"version":"6.12.115","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.59","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.13","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/trace/ring_buffer.c"]}],"references":["https://git.kernel.org/stable/c/32751946f9b3e502e3d6e42d98b343473112f887","https://git.kernel.org/stable/c/029770f5badedc0f0ff85fc45e24785cbbee4a67","https://git.kernel.org/stable/c/68e6ab180cfb6dfa79652f41ed7899a6d4cf5438","https://git.kernel.org/stable/c/89bab1dba8a0167ef0d819e0f55b6bafa038e87f"],"weaknesses":[],"ingestedAt":"2026-10-30T13:02:04.640Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/99xxx/CVE-2026-99158.json","commit":"cb14bf1b43b0c9f05f7f40eae2246263fd430780","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-99158","state":"PUBLISHED","datePublished":"2026-10-28T10:35:11.848Z","dateUpdated":"2026-10-30T12:42:24.782Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:25:14.397Z"},"containers":{"cna":{"title":"ring-buffer: Fix false warning in ring_buffer_map_get_reader()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nring-buffer: Fix false warning in ring_buffer_map_get_reader()\n\nThe mmap reader can warn when it catches up with a writer that is still\ncommitting events. rb_get_reader_page() returns NULL in this case, but\nring_buffer_map_get_reader() treats that result as an error.\n\nThe initial rb_per_cpu_empty() check filters out an empty buffer, but it\ndoes not guarantee that the next reader page has committed data. Writers\ndo not take reader_lock and can advance commit_page before publishing the\ncommitted length on the new page. rb_get_reader_page() can swap to that\npage, catch up with the writer and return NULL.\n\nHandle NULL through the existing no-data exit without warning. Remove the\ncaller's reader_page == commit_page check as well, since the reader-page\nhelper already handles that case. The existing metadata update and return\npath remain in place."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"117c39200d9d760cbd5944bb89efb7b9c51965aa","status":"affected","lessThan":"32751946f9b3e502e3d6e42d98b343473112f887","versionType":"git"},{"version":"117c39200d9d760cbd5944bb89efb7b9c51965aa","status":"affected","lessThan":"029770f5badedc0f0ff85fc45e24785cbbee4a67","versionType":"git"},{"version":"117c39200d9d760cbd5944bb89efb7b9c51965aa","status":"affected","lessThan":"68e6ab180cfb6dfa79652f41ed7899a6d4cf5438","versionType":"git"},{"version":"117c39200d9d760cbd5944bb89efb7b9c51965aa","status":"affected","lessThan":"89bab1dba8a0167ef0d819e0f55b6bafa038e87f","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/trace/ring_buffer.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.10","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.10","versionType":"semver"},{"version":"6.12.115","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.59","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.13","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/trace/ring_buffer.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/32751946f9b3e502e3d6e42d98b343473112f887"},{"url":"https://git.kernel.org/stable/c/029770f5badedc0f0ff85fc45e24785cbbee4a67"},{"url":"https://git.kernel.org/stable/c/68e6ab180cfb6dfa79652f41ed7899a6d4cf5438"},{"url":"https://git.kernel.org/stable/c/89bab1dba8a0167ef0d819e0f55b6bafa038e87f"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-30T12:42:24.782Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.10","versionEndExcluding":"6.12.115"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.10","versionEndExcluding":"6.18.59"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.10","versionEndExcluding":"7.2.13"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.10","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}