CVE-2026-64525

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-64525", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.794Z", "datePublished": "2026-07-25T09:20:49.256Z", "dateUpdated": "2026-10-30T12:27:58.969Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-30T12:27:58.969Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: move policy_bydst RCU sync from per-netns .exit to .pre_exit\n\nThe struct pernet_operations docstring in include/net/net_namespace.h\nexplicitly warns against blocking RCU primitives in .exit handlers:\n\n Exit methods using blocking RCU primitives, such as\n synchronize_rcu(), should be implemented via exit_batch.\n [...]\n Please, avoid synchronize_rcu() at all, where it's possible.\n\n Note that a combination of pre_exit() and exit() can\n be used, since a synchronize_rcu() is guaranteed between\n the calls.\n\nxfrm_policy_fini() violates this: it calls synchronize_rcu() before\nfreeing the policy_bydst hash tables (so no RCU reader is mid-\ntraversal at free time), but runs from xfrm_net_ops.exit -- once per\nnamespace -- so a cleanup_net() of N namespaces pays N full RCU\ngrace periods serially.\n\nUse the documented pre_exit/exit split. Move the policy flush (and\nthe workqueue drains it depends on) into a new .pre_exit handler;\nxfrm_policy_fini() then runs in .exit and frees the hash tables\nafter the synchronize_rcu_expedited() that cleanup_net() guarantees\nbetween the two phases. Providing O(1) RCU grace periods per batch\ninstead of O(N).\n\nObserved on Linux 6.18 with a workload doing unshare(CLONE_NEWNET)\nat ~13/sec sustained: cleanup_net() and the netns_wq rescuer kthread\nboth stuck in xfrm_policy_fini()'s synchronize_rcu(), >300k struct\nnet accumulated in the cleanup queue, Percpu in /proc/meminfo climbed\nto 130+ GB on 256-CPU hosts, and memcg OOMs followed. setup_net and\n__put_net counts were balanced, ruling out a refcount leak."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/xfrm/xfrm_policy.c"], "versions": [{"version": "438b1f668ad58f46ce699bb48e4698a7839e3f9e", "lessThan": "bca6386dc08750fc7cdcbc7683473748ba3114b9", "status": "affected", "versionType": "git"}, {"version": "3733fce2871c9bca9dd18a1a23b1432ea215a094", "lessThan": "91cc13978ab0bc6f669139f53e7e613a860d10e0", "status": "affected", "versionType": "git"}, {"version": "069daad4f2ae9c5c108131995529d5f02392c446", "lessThan": "d14ae8ef88c2c6590e107db61b6adce148cec7b3", "status": "affected", "versionType": "git"}, {"version": "069daad4f2ae9c5c108131995529d5f02392c446", "lessThan": "3e52417318473782012b236d0325bf7d2266a597", "status": "affected", "versionType": "git"}, {"version": "b2faee12538b5b008eaef65a4201eb29cb5cefb3", "status": "affected", "versionType": "git"}, {"version": "b66920a3348c0f63ba18365248fa21fbf0b3a937", "status": "affected", "versionType": "git"}, {"version": "33a3149dd81a1e2f52b80ee1e0fc380b39f3d028", "status": "affected", "versionType": "git"}, {"version": "6.12.83", "lessThan": "6.12.93", "status": "affected", "versionType": "semver"}, {"version": "6.18.24", "lessThan": "6.18.35", "status": "affected", "versionType": "semver"}, {"version": "6.1.191", "lessThan": "6.2", "status": "affected", "versionType": "semver"}, {"version": "6.6.136", "lessThan": "6.7", "status": "affected", "versionType": "semver"}, {"version": "6.19.14", "lessThan": "6.20", "status": "affected", "versionType": "semver"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/xfrm/xfrm_policy.c"], "versions": [{"version": "7.0", "status": "affected"}, {"version": "0", "lessThan": "7.0", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.93", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.35", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.0.12", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1", "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": "6.12.83", "versionEndExcluding": "6.12.93"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.18.24", "versionEndExcluding": "6.18.35"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.0", "versionEndExcluding": "7.0.12"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.0", "versionEndExcluding": "7.1"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1.191"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6.136"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19.14"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/bca6386dc08750fc7cdcbc7683473748ba3114b9"}, {"url": "https://git.kernel.org/stable/c/91cc13978ab0bc6f669139f53e7e613a860d10e0"}, {"url": "https://git.kernel.org/stable/c/d14ae8ef88c2c6590e107db61b6adce148cec7b3"}, {"url": "https://git.kernel.org/stable/c/3e52417318473782012b236d0325bf7d2266a597"}], "title": "xfrm: move policy_bydst RCU sync from per-netns .exit to .pre_exit", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["net/xfrm/xfrm_policy.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "bca6386dc08750fc7cdcbc7683473748ba3114b9", "status": "affected", "version": "438b1f668ad58f46ce699bb48e4698a7839e3f9e", "versionType": "git"}, {"lessThan": "91cc13978ab0bc6f669139f53e7e613a860d10e0", "status": "affected", "version": "3733fce2871c9bca9dd18a1a23b1432ea215a094", "versionType": "git"}, {"lessThan": "d14ae8ef88c2c6590e107db61b6adce148cec7b3", "status": "affected", "version": "069daad4f2ae9c5c108131995529d5f02392c446", "versionType": "git"}, {"lessThan": "3e52417318473782012b236d0325bf7d2266a597", "status": "affected", "version": "069daad4f2ae9c5c108131995529d5f02392c446", "versionType": "git"}, {"status": "affected", "version": "b2faee12538b5b008eaef65a4201eb29cb5cefb3", "versionType": "git"}, {"status": "affected", "version": "b66920a3348c0f63ba18365248fa21fbf0b3a937", "versionType": "git"}, {"status": "affected", "version": "33a3149dd81a1e2f52b80ee1e0fc380b39f3d028", "versionType": "git"}, {"lessThan": "6.12.93", "status": "affected", "version": "6.12.83", "versionType": "semver"}, {"lessThan": "6.18.35", "status": "affected", "version": "6.18.24", "versionType": "semver"}, {"lessThan": "6.2", "status": "affected", "version": "6.1.191", "versionType": "semver"}, {"lessThan": "6.7", "status": "affected", "version": "6.6.136", "versionType": "semver"}, {"lessThan": "6.20", "status": "affected", "version": "6.19.14", "versionType": "semver"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["net/xfrm/xfrm_policy.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "7.0"}, {"lessThan": "7.0", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.93", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.35", "versionType": "semver"}, {"lessThanOrEqual": "7.0.*", "status": "unaffected", "version": "7.0.12", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.1", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: move policy_bydst RCU sync from per-netns .exit to .pre_exit\n\nThe struct pernet_operations docstring in include/net/net_namespace.h\nexplicitly warns against blocking RCU primitives in .exit handlers:\n\n Exit methods using blocking RCU primitives, such as\n synchronize_rcu(), should be implemented via exit_batch.\n [...]\n Please, avoid synchronize_rcu() at all, where it's possible.\n\n Note that a combination of pre_exit() and exit() can\n be used, since a synchronize_rcu() is guaranteed between\n the calls.\n\nxfrm_policy_fini() violates this: it calls synchronize_rcu() before\nfreeing the policy_bydst hash tables (so no RCU reader is mid-\ntraversal at free time), but runs from xfrm_net_ops.exit -- once per\nnamespace -- so a cleanup_net() of N namespaces pays N full RCU\ngrace periods serially.\n\nUse the documented pre_exit/exit split. Move the policy flush (and\nthe workqueue drains it depends on) into a new .pre_exit handler;\nxfrm_policy_fini() then runs in .exit and frees the hash tables\nafter the synchronize_rcu_expedited() that cleanup_net() guarantees\nbetween the two phases. Providing O(1) RCU grace periods per batch\ninstead of O(N).\n\nObserved on Linux 6.18 with a workload doing unshare(CLONE_NEWNET)\nat ~13/sec sustained: cleanup_net() and the netns_wq rescuer kthread\nboth stuck in xfrm_policy_fini()'s synchronize_rcu(), >300k struct\nnet accumulated in the cleanup queue, Percpu in /proc/meminfo climbed\nto 130+ GB on 256-CPU hosts, and memcg OOMs followed. setup_net and\n__put_net counts were balanced, ruling out a refcount leak."}], "id": "CVE-2026-64525", "lastModified": "2026-11-03T18:15:39.353", "metrics": {}, "published": "2026-07-25T10:17:38.830", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/3e52417318473782012b236d0325bf7d2266a597"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/91cc13978ab0bc6f669139f53e7e613a860d10e0"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/bca6386dc08750fc7cdcbc7683473748ba3114b9"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/d14ae8ef88c2c6590e107db61b6adce148cec7b3"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Awaiting Analysis"}

{"bugzilla": {"description": "kernel: xfrm: move policy_bydst RCU sync from per-netns .exit to .pre_exit", "id": "2507136", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2507136"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.0", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-821", "details": ["A flaw was found in the Linux kernel's `xfrm` (IPSec framework) component. An issue with improper RCU (Read-Copy-Update) synchronization in the `xfrm_policy_fini()` function, specifically the serial execution of `synchronize_rcu()` for each network namespace during cleanup, can lead to a Denial of Service (DoS). Under specific workloads involving frequent network namespace creation and destruction, this can cause system processes to become unresponsive, accumulate cleanup tasks, and consume excessive memory, ultimately leading to Out-Of-Memory (OOM) conditions."], "name": "CVE-2026-64525", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "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-2026-64525\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-64525\nhttps://lore.kernel.org/linux-cve-announce/2026072533-CVE-2026-64525-b7fd@gregkh/T"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[438b1f668ad58f46ce699bb48e4698a7839e3f9e,bca6386dc08750fc7cdcbc7683473748ba3114b9)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[3733fce2871c9bca9dd18a1a23b1432ea215a094,91cc13978ab0bc6f669139f53e7e613a860d10e0)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[069daad4f2ae9c5c108131995529d5f02392c446,d14ae8ef88c2c6590e107db61b6adce148cec7b3)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[069daad4f2ae9c5c108131995529d5f02392c446,3e52417318473782012b236d0325bf7d2266a597)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "b66920a3348c0f63ba18365248fa21fbf0b3a937"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "33a3149dd81a1e2f52b80ee1e0fc380b39f3d028"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[6.12.83,6.12.93)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[6.18.24,6.18.35)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[6.6.136,6.7)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[6.19.14,6.20)"}}], "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": "7.0"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,7.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.93,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.35,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.0.12,7.1.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,*]"}}], "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": "2026-07-25T23:45:03.753034+00:00", "updated": "2026-08-05T00:15:04.507749+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}