CVE-2026-64418

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-64418", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.786Z", "datePublished": "2026-07-25T08:50:57.594Z", "dateUpdated": "2026-08-17T04:55:17.788Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T04:55:17.788Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm: shrinker: fix shrinker_info teardown race with expansion\n\nexpand_shrinker_info() iterates all visible memcgs under shrinker_mutex,\nincluding memcgs that have not finished ->css_online() yet.\n\nOnce pn->shrinker_info has been published, teardown must stay serialized\nwith expand_shrinker_info() until that memcg is either fully online or no\nlonger visible to iteration. Today alloc_shrinker_info() breaks that rule\nby dropping shrinker_mutex before freeing a partially initialized\nshrinker_info array, which may cause the following race:\n\nCPU0 CPU1\n==== ====\n\ncss_create\n--> list_add_tail_rcu(&css->sibling, &parent_css->children);\n online_css\n --> mem_cgroup_css_online\n --> alloc_shrinker_info\n --> alloc node0 info\n rcu_assign_pointer(C->node0->shrinker_info, old0)\n alloc node1 info -> FAIL -> goto err\n mutex_unlock(shrinker_mutex)\n\n shrinker_alloc()\n --> shrinker_memcg_alloc\n --> mutex_lock(shrinker_mutex)\n expand_shrinker_info\n --> mem_cgroup_iter see the memcg\n expand_one_shrinker_info\n --> old0 = C->node0->shrinker_info\n memcpy(new->unit, old0->unit, ...);\n\n free_shrinker_info\n --> kvfree(old0);\n\n /* double free !! */\n kvfree_rcu(old0, rcu);\n\nThe same problem exists later in mem_cgroup_css_online(). If\nalloc_shrinker_info() succeeds but a subsequent objcg allocation fails,\nthe free_objcg -> free_shrinker_info() unwind path tears down the already\npublished pn->shrinker_info arrays without shrinker_mutex. The\nexpand_one_shrinker_info() can race with that teardown in the same way,\nleading to use-after-free or double-free of the old shrinker_info.\n\nFix this by serializing shrinker_info teardown with shrinker_mutex, and by\nkeeping alloc_shrinker_info() error cleanup inside the locked section."}], "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 - The vulnerable path is reachable through local cgroup mkdir operations raced against memcg-aware shrinker allocation, such as mounting new tmpfs instances.\nAC:L - An attacker can repeatedly create cgroups, induce allocation pressure, and concurrently allocate shrinkers, controlling both sides of the race and widening it through repetition.\nPR:L - An unprivileged user with a delegated cgroup v2 subtree can create memory cgroups, while user namespaces provide the capability needed to mount user-namespace-enabled filesystems.\nUI:N - Exploitation requires no action by another user once the attacker can execute the concurrent local operations.\nS:U - The corruption occurs within the kernel and represents ordinary local privilege escalation within the same security authority.\nC:H - The use-after-free and delayed double-free permit heap reuse and manipulation of dangling shrinker unit pointers, potentially enabling arbitrary kernel-memory disclosure.\nI:H - The dangling pointers, atomic operations on freed units, and double-free can provide arbitrary kernel-memory corruption and control-flow hijacking.\nA:H - The use-after-free or double-free can directly cause a kernel oops, panic, or other system-wide failure."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["mm/shrinker.c"], "versions": [{"version": "307bececcd1205bcb67a3c0d53a69db237ccc9d4", "lessThan": "b9a280a9a454ed514636351d53fe2a233dc5054b", "status": "affected", "versionType": "git"}, {"version": "307bececcd1205bcb67a3c0d53a69db237ccc9d4", "lessThan": "6465ff3ce65131c774a312d450abe10f4b9f3875", "status": "affected", "versionType": "git"}, {"version": "307bececcd1205bcb67a3c0d53a69db237ccc9d4", "lessThan": "284c267f013e45d8c89d9fb9373105dc8e6c0947", "status": "affected", "versionType": "git"}, {"version": "307bececcd1205bcb67a3c0d53a69db237ccc9d4", "lessThan": "65476d31d8056e859c48580f82295ce159196ffe", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["mm/shrinker.c"], "versions": [{"version": "6.7", "status": "affected"}, {"version": "0", "lessThan": "6.7", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.96", "lessThanOrEqual": "6.12.*", "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": "6.7", "versionEndExcluding": "6.12.96"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.18.39"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "7.1.4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "7.2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/b9a280a9a454ed514636351d53fe2a233dc5054b"}, {"url": "https://git.kernel.org/stable/c/6465ff3ce65131c774a312d450abe10f4b9f3875"}, {"url": "https://git.kernel.org/stable/c/284c267f013e45d8c89d9fb9373105dc8e6c0947"}, {"url": "https://git.kernel.org/stable/c/65476d31d8056e859c48580f82295ce159196ffe"}], "title": "mm: shrinker: fix shrinker_info teardown race with expansion", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["mm/shrinker.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "b9a280a9a454ed514636351d53fe2a233dc5054b", "status": "affected", "version": "307bececcd1205bcb67a3c0d53a69db237ccc9d4", "versionType": "git"}, {"lessThan": "6465ff3ce65131c774a312d450abe10f4b9f3875", "status": "affected", "version": "307bececcd1205bcb67a3c0d53a69db237ccc9d4", "versionType": "git"}, {"lessThan": "284c267f013e45d8c89d9fb9373105dc8e6c0947", "status": "affected", "version": "307bececcd1205bcb67a3c0d53a69db237ccc9d4", "versionType": "git"}, {"lessThan": "65476d31d8056e859c48580f82295ce159196ffe", "status": "affected", "version": "307bececcd1205bcb67a3c0d53a69db237ccc9d4", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["mm/shrinker.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.7"}, {"lessThan": "6.7", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.96", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.39", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.4", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "38A8100E-2B1A-462F-AEE9-8901B870FEF2", "versionEndExcluding": "6.12.96", "versionStartIncluding": "6.7", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "914AE4BC-3D59-4C5A-9DB5-9CE327B429F7", "versionEndExcluding": "6.18.39", "versionStartIncluding": "6.13", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "6228DDD6-4557-4AA3-9F43-AB995D471E42", "versionEndExcluding": "7.1.4", "versionStartIncluding": "6.19", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.2:rc1:*:*:*:*:*:*", "matchCriteriaId": "5E8B9085-7ADB-4A05-89EF-12949B6A0509", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.2:rc2:*:*:*:*:*:*", "matchCriteriaId": "1FC0D50D-9D58-4947-A197-A5A3FF07E7E3", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm: shrinker: fix shrinker_info teardown race with expansion\n\nexpand_shrinker_info() iterates all visible memcgs under shrinker_mutex,\nincluding memcgs that have not finished ->css_online() yet.\n\nOnce pn->shrinker_info has been published, teardown must stay serialized\nwith expand_shrinker_info() until that memcg is either fully online or no\nlonger visible to iteration. Today alloc_shrinker_info() breaks that rule\nby dropping shrinker_mutex before freeing a partially initialized\nshrinker_info array, which may cause the following race:\n\nCPU0 CPU1\n==== ====\n\ncss_create\n--> list_add_tail_rcu(&css->sibling, &parent_css->children);\n online_css\n --> mem_cgroup_css_online\n --> alloc_shrinker_info\n --> alloc node0 info\n rcu_assign_pointer(C->node0->shrinker_info, old0)\n alloc node1 info -> FAIL -> goto err\n mutex_unlock(shrinker_mutex)\n\n shrinker_alloc()\n --> shrinker_memcg_alloc\n --> mutex_lock(shrinker_mutex)\n expand_shrinker_info\n --> mem_cgroup_iter see the memcg\n expand_one_shrinker_info\n --> old0 = C->node0->shrinker_info\n memcpy(new->unit, old0->unit, ...);\n\n free_shrinker_info\n --> kvfree(old0);\n\n /* double free !! */\n kvfree_rcu(old0, rcu);\n\nThe same problem exists later in mem_cgroup_css_online(). If\nalloc_shrinker_info() succeeds but a subsequent objcg allocation fails,\nthe free_objcg -> free_shrinker_info() unwind path tears down the already\npublished pn->shrinker_info arrays without shrinker_mutex. The\nexpand_one_shrinker_info() can race with that teardown in the same way,\nleading to use-after-free or double-free of the old shrinker_info.\n\nFix this by serializing shrinker_info teardown with shrinker_mutex, and by\nkeeping alloc_shrinker_info() error cleanup inside the locked section."}], "id": "CVE-2026-64418", "lastModified": "2026-09-04T15:24:49.577", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-07-25T10:17:25.727", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/284c267f013e45d8c89d9fb9373105dc8e6c0947"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/6465ff3ce65131c774a312d450abe10f4b9f3875"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/65476d31d8056e859c48580f82295ce159196ffe"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/b9a280a9a454ed514636351d53fe2a233dc5054b"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-362"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"bugzilla": {"description": "kernel: mm: shrinker: fix shrinker_info teardown race with expansion", "id": "2507285", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2507285"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-364", "details": ["A flaw was found in the Linux kernel's memory management (mm) shrinker subsystem. A race condition exists where the `shrinker_info` array can be prematurely freed while still accessible, leading to a use-after-free or double-free vulnerability. This memory corruption can be exploited by a local attacker to cause system instability or a denial of service."], "name": "CVE-2026-64418", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-07-25T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-64418\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-64418\nhttps://lore.kernel.org/linux-cve-announce/2026072533-CVE-2026-64418-4aed@gregkh/T"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[307bececcd1205bcb67a3c0d53a69db237ccc9d4,b9a280a9a454ed514636351d53fe2a233dc5054b)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[307bececcd1205bcb67a3c0d53a69db237ccc9d4,6465ff3ce65131c774a312d450abe10f4b9f3875)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[307bececcd1205bcb67a3c0d53a69db237ccc9d4,284c267f013e45d8c89d9fb9373105dc8e6c0947)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[307bececcd1205bcb67a3c0d53a69db237ccc9d4,65476d31d8056e859c48580f82295ce159196ffe)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "6.7"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,6.7)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.96,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.39,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.1.4,7.2.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.2-rc3,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-07-25T18:30:17.014973+00:00", "updated": "2026-09-04T22:45:04.121184+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}