{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-72220", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-09T03:40:39.913Z", "datePublished": "2026-08-15T05:54:13.800Z", "dateUpdated": "2026-08-17T05:41:41.598Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T05:41:41.598Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsunrpc: harden rq_procinfo lifecycle to prevent double-free\n\nThe svc_release_rqst() function executes the callback inside\nrqstp->rq_procinfo->pc_release. However, if a worker thread begins\nprocessing a new request and encounters an early error path (e.g.,\nunsupported protocol, short frame, or bad auth) before a valid\nrq_procinfo is installed, a stale release hook can be re-triggered\nagainst reused state from the previous RPC, resulting in a double-free\nor use-after-free vulnerability.\n\nHarden the lifecycle of rq_procinfo by:\n1. Ensuring svc_release_rqst() always clears rq_procinfo after the\n optional pc_release() call, regardless of whether the hook exists.\n2. Explicitly clearing rq_procinfo at request entry in svc_process()\n before any early decode or drop paths.\n3. Ensuring svc_process_bc() does the same at backchannel entry.\n\nThis guarantees that error flows will not encounter a non-NULL stale\nrq_procinfo pointer when there is nothing to release." } ], "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 - The flaw is in server-side SUNRPC request handling reached from remote RPC over TCP/UDP/RDMA transports used by nfsd and lockd (svc_recv→svc_handle_xprt→svc_process), exploitable by sending crafted ONC/RPC packets to listening NFS/NLM ports.\nAC:L - An attacker controls the RPC sequence and timing (valid request then malformed/short/bad-auth/bad-prog packet on the same pooled worker) to reliably re-trigger a stale pc_release without depending on uncontrollable layout or victim state.\nPR:N - Trigger paths include pre-authentication failures (garbage credentials, unknown program/version, short frames) that still call svc_release_rqst; stale rq_procinfo can be left by any prior RPC on the same worker, so no attacker credentials are required.\nUI:N - Exploitation requires only network RPC traffic to an already-running NFS/NLM server; no end-user actions such as mounting a share or opening files are needed beyond normal server exposure.\nS:U - Impact is kernel heap corruption and privilege escalation within the host kernel context; it does not inherently cross a VM, container, or IOMMU security boundary to another authority.\nC:H - The bug is an explicit double-free/use-after-free of per-request NFS release state (e.g. nfsd4_release_compoundargs kfree/vfree chains and fh_put paths), enabling arbitrary kernel memory disclosure when exploited.\nI:H - Re-invoking pc_release on reused svc_rqst buffers corrupts heap metadata and object lifetimes, providing a standard kernel double-free/UAF primitive suitable for arbitrary write and code execution.\nA:H - Repeated or mistimed pc_release calls can immediately panic the kernel via SLUB double-free detection, oops, or wedged nfsd worker threads, causing complete loss of availability on NFS-serving systems." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/sunrpc/svc.c" ], "versions": [ { "version": "d9adbb6e10bf7d4223d3d521ede1b2052903bc5e", "lessThan": "66014ab165cb01bfef5836939412a8ef98d5d5ff", "status": "affected", "versionType": "git" }, { "version": "d9adbb6e10bf7d4223d3d521ede1b2052903bc5e", "lessThan": "31ba490c02d476a5e4f90b8845932ac9db8aa71b", "status": "affected", "versionType": "git" }, { "version": "d9adbb6e10bf7d4223d3d521ede1b2052903bc5e", "lessThan": "18d216788bef06332ff8901670ecf1ed8f6eb614", "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/svc.c" ], "versions": [ { "version": "6.18", "status": "affected" }, { "version": "0", "lessThan": "6.18", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.40", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.5", "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": "6.18", "versionEndExcluding": "6.18.40" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.18", "versionEndExcluding": "7.1.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.18", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/66014ab165cb01bfef5836939412a8ef98d5d5ff" }, { "url": "https://git.kernel.org/stable/c/31ba490c02d476a5e4f90b8845932ac9db8aa71b" }, { "url": "https://git.kernel.org/stable/c/18d216788bef06332ff8901670ecf1ed8f6eb614" } ], "title": "sunrpc: harden rq_procinfo lifecycle to prevent double-free", "x_generator": { "engine": "bippy-1.2.0" } } } }