{"id":"CVE-2026-89643","state":"PUBLISHED","title":"audit: avoid dropping live tree ref on fsnotify rule autoremove","description":"In the Linux kernel, the following vulnerability has been resolved:\n\naudit: avoid dropping live tree ref on fsnotify rule autoremove\n\naudit_del_rule() is used for both netlink deletion templates and internal\nfsnotify autoremove.  The former passes a parsed template which owns a\ntemporary tree reference; the latter passes the installed entry itself.\n\nThe unconditional audit_put_tree() at the end of audit_del_rule() assumes\nthe template case.  For mixed AUDIT_DIR plus AUDIT_EXE rules, an fsnotify\nautoremove event therefore drops the installed rule's live tree reference.\nRepeating this across rules sharing the same tree can free the tree while\nanother rule still references it, and a later autoremove dereferences the\nfreed pathname while comparing rules.\n\nMove the temporary-tree put to audit_rule_change(), the caller that owns\ndeletion templates.  Keep it in the AUDIT_DEL_RULE cleanup so both\nsuccessful deletion and -ENOENT still release the parser-owned tree.\n\n[PM: dropped unnecessary comment for line length reasons]","publishedAt":"2026-09-11T19:45:35.523Z","updatedAt":"2026-10-19T08:50:15.077Z","severity":{"score":9.8,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"34d99af52ad40bd498ba66970579a5bc1fb1a3bc","status":"affected","lessThan":"9cac21f8eb82675ed19fb955b8bbb9dd14cc3d58","versionType":"git"},{"version":"34d99af52ad40bd498ba66970579a5bc1fb1a3bc","status":"affected","lessThan":"b322cc7adcd2e6ec1594d187533a126506ab545c","versionType":"git"},{"version":"34d99af52ad40bd498ba66970579a5bc1fb1a3bc","status":"affected","lessThan":"695c85dc345a4e0292739f004c261bedef3f27e6","versionType":"git"},{"version":"34d99af52ad40bd498ba66970579a5bc1fb1a3bc","status":"affected","lessThan":"01b0ec8c397be65ff710777c97017ca1de56ef8e","versionType":"git"},{"version":"34d99af52ad40bd498ba66970579a5bc1fb1a3bc","status":"affected","lessThan":"cf37b61b5420fd4600fe78cf8c24da6e4d9bfe28","versionType":"git"},{"version":"34d99af52ad40bd498ba66970579a5bc1fb1a3bc","status":"affected","lessThan":"636a99bab36ba27515363d325866c0273ac83b3e","versionType":"git"},{"version":"34d99af52ad40bd498ba66970579a5bc1fb1a3bc","status":"affected","lessThan":"583cf579b32d99e3fe4e9c8ecc4d852e3708fbec","versionType":"git"},{"version":"34d99af52ad40bd498ba66970579a5bc1fb1a3bc","status":"affected","lessThan":"783f0f0974c156aca630f4ffff248671082a098d","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/auditfilter.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.3","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.3","versionType":"semver"},{"version":"5.10.270","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.221","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.188","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.157","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.109","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.50","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.4","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/auditfilter.c"]}],"references":["https://git.kernel.org/stable/c/9cac21f8eb82675ed19fb955b8bbb9dd14cc3d58","https://git.kernel.org/stable/c/b322cc7adcd2e6ec1594d187533a126506ab545c","https://git.kernel.org/stable/c/695c85dc345a4e0292739f004c261bedef3f27e6","https://git.kernel.org/stable/c/01b0ec8c397be65ff710777c97017ca1de56ef8e","https://git.kernel.org/stable/c/cf37b61b5420fd4600fe78cf8c24da6e4d9bfe28","https://git.kernel.org/stable/c/636a99bab36ba27515363d325866c0273ac83b3e","https://git.kernel.org/stable/c/583cf579b32d99e3fe4e9c8ecc4d852e3708fbec","https://git.kernel.org/stable/c/783f0f0974c156aca630f4ffff248671082a098d"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:26.108Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/89xxx/CVE-2026-89643.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-89643","state":"PUBLISHED","datePublished":"2026-09-11T19:45:35.523Z","dateUpdated":"2026-10-19T08:50:15.077Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-11T19:38:34.741Z"},"containers":{"cna":{"title":"audit: avoid dropping live tree ref on fsnotify rule autoremove","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\naudit: avoid dropping live tree ref on fsnotify rule autoremove\n\naudit_del_rule() is used for both netlink deletion templates and internal\nfsnotify autoremove.  The former passes a parsed template which owns a\ntemporary tree reference; the latter passes the installed entry itself.\n\nThe unconditional audit_put_tree() at the end of audit_del_rule() assumes\nthe template case.  For mixed AUDIT_DIR plus AUDIT_EXE rules, an fsnotify\nautoremove event therefore drops the installed rule's live tree reference.\nRepeating this across rules sharing the same tree can free the tree while\nanother rule still references it, and a later autoremove dereferences the\nfreed pathname while comparing rules.\n\nMove the temporary-tree put to audit_rule_change(), the caller that owns\ndeletion templates.  Keep it in the AUDIT_DEL_RULE cleanup so both\nsuccessful deletion and -ENOENT still release the parser-owned tree.\n\n[PM: dropped unnecessary comment for line length reasons]"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"34d99af52ad40bd498ba66970579a5bc1fb1a3bc","status":"affected","lessThan":"9cac21f8eb82675ed19fb955b8bbb9dd14cc3d58","versionType":"git"},{"version":"34d99af52ad40bd498ba66970579a5bc1fb1a3bc","status":"affected","lessThan":"b322cc7adcd2e6ec1594d187533a126506ab545c","versionType":"git"},{"version":"34d99af52ad40bd498ba66970579a5bc1fb1a3bc","status":"affected","lessThan":"695c85dc345a4e0292739f004c261bedef3f27e6","versionType":"git"},{"version":"34d99af52ad40bd498ba66970579a5bc1fb1a3bc","status":"affected","lessThan":"01b0ec8c397be65ff710777c97017ca1de56ef8e","versionType":"git"},{"version":"34d99af52ad40bd498ba66970579a5bc1fb1a3bc","status":"affected","lessThan":"cf37b61b5420fd4600fe78cf8c24da6e4d9bfe28","versionType":"git"},{"version":"34d99af52ad40bd498ba66970579a5bc1fb1a3bc","status":"affected","lessThan":"636a99bab36ba27515363d325866c0273ac83b3e","versionType":"git"},{"version":"34d99af52ad40bd498ba66970579a5bc1fb1a3bc","status":"affected","lessThan":"583cf579b32d99e3fe4e9c8ecc4d852e3708fbec","versionType":"git"},{"version":"34d99af52ad40bd498ba66970579a5bc1fb1a3bc","status":"affected","lessThan":"783f0f0974c156aca630f4ffff248671082a098d","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/auditfilter.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.3","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.3","versionType":"semver"},{"version":"5.10.270","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.221","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.188","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.157","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.109","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.50","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.4","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/auditfilter.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/9cac21f8eb82675ed19fb955b8bbb9dd14cc3d58"},{"url":"https://git.kernel.org/stable/c/b322cc7adcd2e6ec1594d187533a126506ab545c"},{"url":"https://git.kernel.org/stable/c/695c85dc345a4e0292739f004c261bedef3f27e6"},{"url":"https://git.kernel.org/stable/c/01b0ec8c397be65ff710777c97017ca1de56ef8e"},{"url":"https://git.kernel.org/stable/c/cf37b61b5420fd4600fe78cf8c24da6e4d9bfe28"},{"url":"https://git.kernel.org/stable/c/636a99bab36ba27515363d325866c0273ac83b3e"},{"url":"https://git.kernel.org/stable/c/583cf579b32d99e3fe4e9c8ecc4d852e3708fbec"},{"url":"https://git.kernel.org/stable/c/783f0f0974c156aca630f4ffff248671082a098d"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":9.8,"baseSeverity":"CRITICAL"},"scenarios":[{"lang":"en","value":"AV:N - audit_autoremove_mark_rule() runs from fsnotify FS_MOVE_SELF/FS_DELETE_SELF/FS_UNMOUNT on the AUDIT_EXE parent directory; nfsd and ksmbd vfs_rename/vfs_rmdir of that directory reach the same path over the network, not only local renameat/rmdir.\nAC:L - Each EXE fsnotify autoremove deterministically extra-puts the live shared audit_tree; the attacker issues sequential directory renames/rmdirs they fully control and needs no race or memory layout beyond their influence.\nPR:N - Triggering requires only renaming or rmdir'ing the parent directory of an audited executable on a local or NFS/SMB-exported path; a remote client needs no local account, CAP_AUDIT_CONTROL, or init-namespace root beyond export write access.\nUI:N - The attacker triggers autoremove with their own rename/rmdir (local or via nfsd/ksmbd); no other user must open files, mount a filesystem, or otherwise interact.\nS:U - The use-after-free corrupts host kernel heap (struct audit_tree) and stays within the same kernel security authority; it is not a VM escape, IOMMU bypass, or other documented cross-boundary impact.\nC:H - Use-after-free of the shared audit_tree lets a later audit_compare_rule() strcmp the freed pathname and remaining rules dereference attacker-reclaimed tree objects, enabling arbitrary kernel reads.\nI:H - The dangling tree is then used in audit_remove_tree_rule() list_del/list_move and prune_one() after extra puts free it, enabling heap spraying, list corruption, arbitrary writes, and control-flow hijack.\nA:H - Dereferencing the freed audit_tree pathname or underflowing its refcount during prune oopses/panics the kernel; the UAF can be triggered repeatedly for denial of service."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T08:50:15.077Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.3","versionEndExcluding":"5.10.270"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.3","versionEndExcluding":"5.15.221"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.3","versionEndExcluding":"6.1.188"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.3","versionEndExcluding":"6.6.157"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.3","versionEndExcluding":"6.12.109"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.3","versionEndExcluding":"6.18.50"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.3","versionEndExcluding":"7.2.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.3","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-89643","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T19:24:59.658694Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-16T19:26:46.069Z"}}]}}}