{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64300","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-07-19T15:36:31.778Z","datePublished":"2026-07-25T08:49:36.372Z","dateUpdated":"2026-08-17T04:52:58.194Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-17T04:52:58.194Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nperf/aux: Fix page UAF in map_range()\n\nmap_range() reads rb->aux_pages[], rb->aux_nr_pages and rb->aux_pgoff via\nperf_mmap_to_page() while holding only event->mmap_mutex. Those fields are\nserialized by rb->aux_mutex, and mmap_mutex is per event.\n\nThus, two events sharing one rb via PERF_EVENT_IOC_SET_OUTPUT can race\nrb_alloc_aux() with map_range(), leading to a page-UAF scenario as follows:\n\n  CPU 0                           CPU 1\n  =====                           =====\n  rb_alloc_aux()                  map_range()\n  [1]: allocate rb->aux_pages[0]\n  [2]: rb->aux_nr_pages++\n                                  [3]: perf_mmap_to_page()\n                                         returns rb->aux_pages[0]\n                                  [4]: map it as VM_PFNMAP\n  [5]: rb->aux_pgoff = 1\n\n  munmap the page\n  [6]: free rb->aux_pages[0]\n\nPages mapped as VM_PFNMAP have no refcount protection, so CPU 1 holds a\nmapping to a freed physical frame.\n\nFix this by taking rb->aux_mutex across the page walk in map_range()."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - Exploitation uses local perf_event_open(), ioctl(), mmap(), and munmap() operations; no network or physical path reaches map_range().\nAC:L - The attacker controls both racing mappings and the freeing munmap(), can enlarge the AUX allocation window, and can retry without depending on victim-controlled conditions.\nPR:L - An ordinary unprivileged user can create task-scoped AUX events such as Intel PT with exclude_kernel enabled under the upstream default perf_event_paranoid setting.\nUI:N - The attacking process independently creates the events, races the mappings, frees the AUX buffer, and accesses the stale mapping without victim action.\nS:U - Exploitation compromises the host kernel from local userspace but does not inherently cross a separate virtualization or IOMMU security authority.\nC:H - The persistent VM_PFNMAP alias exposes whichever kernel allocation reuses the freed physical frame, enabling disclosure of sensitive kernel memory.\nI:H - The stale page is mapped at offset zero, where pfn_mkwrite permits writes, enabling corruption of a reused kernel page and potential control-flow hijacking.\nA:H - Writing through the stale PFN can corrupt arbitrary kernel-owned page contents and cause an oops, panic, or complete system compromise."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/events/core.c"],"versions":[{"version":"b709eb872e19a19607bbb6d2975bc264d59735cf","lessThan":"c8b7e113f7b61eef2f017e6329c27c2331058c5a","status":"affected","versionType":"git"},{"version":"b709eb872e19a19607bbb6d2975bc264d59735cf","lessThan":"0cff05bd2186020f8706233e261016d149cc24db","status":"affected","versionType":"git"},{"version":"b709eb872e19a19607bbb6d2975bc264d59735cf","lessThan":"5948aaf64f81f217a25dcc2bf6c0779bca19566c","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/events/core.c"],"versions":[{"version":"6.14","status":"affected"},{"version":"0","lessThan":"6.14","status":"unaffected","versionType":"semver"},{"version":"6.18.39","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.1.4","lessThanOrEqual":"7.1.*","status":"unaffected","versionType":"semver"},{"version":"7.2","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14","versionEndExcluding":"6.18.39"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14","versionEndExcluding":"7.1.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14","versionEndExcluding":"7.2"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/c8b7e113f7b61eef2f017e6329c27c2331058c5a"},{"url":"https://git.kernel.org/stable/c/0cff05bd2186020f8706233e261016d149cc24db"},{"url":"https://git.kernel.org/stable/c/5948aaf64f81f217a25dcc2bf6c0779bca19566c"}],"title":"perf/aux: Fix page UAF in map_range()","x_generator":{"engine":"bippy-1.2.0"}}}}