{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-89548", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.723Z", "datePublished": "2026-09-11T19:44:23.298Z", "dateUpdated": "2026-10-19T08:48:41.057Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:48:41.057Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nSUNRPC: always drain cache_cleaner before destroying a cache_detail\n\nsunrpc_destroy_cache_detail() only cancels the global cache_cleaner\ndelayed_work when cache_list is empty. During per-netns teardown\ncache_list is never empty because init_net's caches remain registered,\nso the cancel never fires. After unlink, the caller proceeds to\ncache_destroy_net() which kfrees the cache_detail while cache_clean()\nmay still hold a dangling pointer to it. The result is a\nuse-after-free: cache_dequeue() takes cd->queue_lock on freed memory,\nand cache_put() dereferences cd->cache_put as a function pointer from\nfreed slab.\n\nDrop the list_empty guard so that cancel_delayed_work_sync() always\nruns, ensuring any in-flight cache_clean() completes before the\ncache_detail is freed. Re-arm the cleaner afterwards if other caches\nare still registered." } ], "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 - sunrpc_destroy_cache_detail() runs from per-netns teardown (sunrpc_exit_net, nfsd_net_exit, gss_svc_shutdown_net) when a local task creates and destroys a network namespace; remote NFS/RPC traffic populates caches but never frees cache_detail.\nAC:L - The attacker controls both sides of the race: unshare of a user+net ns queues cache_cleaner at delay 0, writes expired entries via /proc/net/rpc/*/channel (ip_map_parse even calls cache_flush()), and drops the netns so destroy kfree()s cache_detail while cache_clean() still holds it.\nPR:L - Unprivileged users can create a user+network namespace (unshare -Urn). /proc/net/rpc cache files inherit userns-root ownership from proc_net_ns_init, so the attacker can populate and destroy those caches without init-namespace root.\nUI:N - The attacker creates the namespace, writes the cache channel, and tears the netns down from their own processes; no victim mount, file open, or other interaction is required.\nS:U - The use-after-free corrupts host kernel heap (struct cache_detail) within the same kernel security authority and is not a VM escape, IOMMU bypass, or other cross-boundary impact.\nC:H - cache_clean() calls cache_dequeue() and cache_put() on a kfree'd cache_detail; per kernel UAF guidance, reclaim of that slab object yields an arbitrary kernel read primitive.\nI:H - cache_put() invokes cd->cache_put from the freed slab as a function pointer, and cache_dequeue() takes cd->queue_lock on freed memory, giving a control-flow hijack/write primitive.\nA:H - Use-after-free of cache_detail (spinlock on freed queue_lock and an indirect call through freed cache_put) causes a kernel oops or panic even when not fully exploited for code execution." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/sunrpc/cache.c" ], "versions": [ { "version": "820f9442e711a81749e70c40f149fc54c4ce0ca8", "lessThan": "dec787a15c96a5665e9ffc61b429a6a4ab26e6b9", "status": "affected", "versionType": "git" }, { "version": "820f9442e711a81749e70c40f149fc54c4ce0ca8", "lessThan": "5eea874a696201c31e7c2d7badbfa0d90e9961b5", "status": "affected", "versionType": "git" }, { "version": "820f9442e711a81749e70c40f149fc54c4ce0ca8", "lessThan": "cf239de7fdcc8336259b01ea4bcf650dadad1040", "status": "affected", "versionType": "git" }, { "version": "820f9442e711a81749e70c40f149fc54c4ce0ca8", "lessThan": "6d74ecc2be120a0c300b224b7649fe93c0453714", "status": "affected", "versionType": "git" }, { "version": "820f9442e711a81749e70c40f149fc54c4ce0ca8", "lessThan": "9d44836f60c8c29bcdb1471fd9202387c642a890", "status": "affected", "versionType": "git" }, { "version": "820f9442e711a81749e70c40f149fc54c4ce0ca8", "lessThan": "2e861ce2aaa468351a6a47c4cbb4971ebb740c7b", "status": "affected", "versionType": "git" }, { "version": "820f9442e711a81749e70c40f149fc54c4ce0ca8", "lessThan": "3d60fdf951143d6ef4e352e2f8eb852286701726", "status": "affected", "versionType": "git" }, { "version": "820f9442e711a81749e70c40f149fc54c4ce0ca8", "lessThan": "f42d0fda0c67695db6bc704b04b7c10240805377", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/sunrpc/cache.c" ], "versions": [ { "version": "3.4", "status": "affected" }, { "version": "0", "lessThan": "3.4", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.270", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.221", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.188", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.157", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.109", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.50", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.4", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "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": "3.4", "versionEndExcluding": "5.10.270" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.4", "versionEndExcluding": "5.15.221" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.4", "versionEndExcluding": "6.1.188" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.4", "versionEndExcluding": "6.6.157" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.4", "versionEndExcluding": "6.12.109" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.4", "versionEndExcluding": "6.18.50" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.4", "versionEndExcluding": "7.2.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.4", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/dec787a15c96a5665e9ffc61b429a6a4ab26e6b9" }, { "url": "https://git.kernel.org/stable/c/5eea874a696201c31e7c2d7badbfa0d90e9961b5" }, { "url": "https://git.kernel.org/stable/c/cf239de7fdcc8336259b01ea4bcf650dadad1040" }, { "url": "https://git.kernel.org/stable/c/6d74ecc2be120a0c300b224b7649fe93c0453714" }, { "url": "https://git.kernel.org/stable/c/9d44836f60c8c29bcdb1471fd9202387c642a890" }, { "url": "https://git.kernel.org/stable/c/2e861ce2aaa468351a6a47c4cbb4971ebb740c7b" }, { "url": "https://git.kernel.org/stable/c/3d60fdf951143d6ef4e352e2f8eb852286701726" }, { "url": "https://git.kernel.org/stable/c/f42d0fda0c67695db6bc704b04b7c10240805377" } ], "title": "SUNRPC: always drain cache_cleaner before destroying a cache_detail", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2026-89548", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2026-10-16T19:23:39.938577Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:26:42.819Z" } } ] } }