{ "schema_version": "1.6.1", "id": "RPI-CVE-2026-64300", "modified": "2026-10-09T11:39:44Z", "upstream": [ "CVE-2026-64300" ], "published": "2026-07-25T08:51:45Z", "summary": "perf/aux: Fix page UAF in map_range()", "details": "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().", "severity": [ { "type": "CVSS_V3", "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H" } ], "affected": [ { "package": { "ecosystem": "Raspberry Pi OS:13", "name": "linux" }, "versions": [ "1:6.18.29-1+rpt1", "1:6.18.33-1+rpt1", "1:6.18.34-1+rpt1" ], "ecosystem_specific": { "binaries": [ { "binary_name": "linux-image-6.18.29+rpt-rpi-2712", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.29+rpt-rpi-v6", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.29+rpt-rpi-v7", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.29+rpt-rpi-v8", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.29+rpt-rpi-v8-rt", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-2712", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-v6", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-v7", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-v8", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-v8-rt", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-2712", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-v6", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-v7", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-v8", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-v8-rt", "binary_version": "1:6.18.34-1+rpt1" } ] }, "database_specific": { "per_version": { "1:6.18.29-1+rpt1": { "linux_commit": "66318c5b5cd8145a662303af12ed39ac07eb27cc", "upstream_version": "6.18.29", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.18.39" }, "1:6.18.33-1+rpt1": { "linux_commit": "95b85bebbedcaedfa7ca79116ed38b7376fba412", "upstream_version": "6.18.33", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.18.39" }, "1:6.18.34-1+rpt1": { "linux_commit": "c8c7494100e99ee05b11aaa4f0588a223a63d1af", "upstream_version": "6.18.34", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.18.39" } } } } ], "references": [ { "type": "ADVISORY", "url": "https://www.cve.org/CVERecord?id=CVE-2026-64300" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/c8b7e113f7b61eef2f017e6329c27c2331058c5a" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/0cff05bd2186020f8706233e261016d149cc24db" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/5948aaf64f81f217a25dcc2bf6c0779bca19566c" } ], "database_specific": { "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git", "upstream_modified": "2026-08-17T05:24:08Z", "severity": { "source": "kernel CNA", "cvss_v3_score": 7.8, "cvss_v3_severity": "High", "scenario": "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." } } }