{"id":"CVE-2026-45983","state":"PUBLISHED","title":"nfsd: never defer requests during idmap lookup","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: never defer requests during idmap lookup\n\nDuring v4 request compound arg decoding, some ops (e.g. SETATTR)\ncan trigger idmap lookup upcalls. When those upcall responses get\ndelayed beyond the allowed time limit, cache_check() will mark the\nrequest for deferral and cause it to be dropped.\n\nThis prevents nfs4svc_encode_compoundres from being executed, and\nthus the session slot flag NFSD4_SLOT_INUSE never gets cleared.\nSubsequent client requests will fail with NFSERR_JUKEBOX, given\nthat the slot will be marked as in-use, making the SEQUENCE op\nfail.\n\nFix this by making sure that the RQ_USEDEFERRAL flag is always\nclear during nfs4svc_decode_compoundargs(), since no v4 request\nshould ever be deferred.","publishedAt":"2026-05-27T12:18:41.619Z","updatedAt":"2026-05-27T12:18:41.619Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"2f425878b6a71571341dcd3f9e9d1a6f6355da9c","status":"affected","lessThan":"b9abb760db20504240a7147f27934d900cd80b23","versionType":"git"},{"version":"2f425878b6a71571341dcd3f9e9d1a6f6355da9c","status":"affected","lessThan":"3a72c7dedc99b321e0f267e4e999e5baf07c4593","versionType":"git"},{"version":"2f425878b6a71571341dcd3f9e9d1a6f6355da9c","status":"affected","lessThan":"99e17b20fddac19a228d213e00f6b9e1c10daff9","versionType":"git"},{"version":"2f425878b6a71571341dcd3f9e9d1a6f6355da9c","status":"affected","lessThan":"243f71ed873ff3feeb6f9b5cb145d63f7188b4c4","versionType":"git"},{"version":"2f425878b6a71571341dcd3f9e9d1a6f6355da9c","status":"affected","lessThan":"063a6f22478ef929625000a2caf54667725c1dfd","versionType":"git"},{"version":"2f425878b6a71571341dcd3f9e9d1a6f6355da9c","status":"affected","lessThan":"d75ec4504a4340b033b15cad0303988b3089dd93","versionType":"git"},{"version":"2f425878b6a71571341dcd3f9e9d1a6f6355da9c","status":"affected","lessThan":"8dff54fe88c0dcd4c55bff9fc2fa6ca968290826","versionType":"git"},{"version":"2f425878b6a71571341dcd3f9e9d1a6f6355da9c","status":"affected","lessThan":"f9c206cdc4266caad6a9a7f46341420a10f03ccb","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/nfsd/nfs4idmap.c","fs/nfsd/nfs4proc.c","fs/nfsd/nfs4xdr.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.30","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.30","versionType":"semver"},{"version":"5.10.252","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.202","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.165","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.128","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.75","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.14","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.4","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/nfsd/nfs4idmap.c","fs/nfsd/nfs4proc.c","fs/nfsd/nfs4xdr.c"]}],"references":["https://git.kernel.org/stable/c/b9abb760db20504240a7147f27934d900cd80b23","https://git.kernel.org/stable/c/3a72c7dedc99b321e0f267e4e999e5baf07c4593","https://git.kernel.org/stable/c/99e17b20fddac19a228d213e00f6b9e1c10daff9","https://git.kernel.org/stable/c/243f71ed873ff3feeb6f9b5cb145d63f7188b4c4","https://git.kernel.org/stable/c/063a6f22478ef929625000a2caf54667725c1dfd","https://git.kernel.org/stable/c/d75ec4504a4340b033b15cad0303988b3089dd93","https://git.kernel.org/stable/c/8dff54fe88c0dcd4c55bff9fc2fa6ca968290826","https://git.kernel.org/stable/c/f9c206cdc4266caad6a9a7f46341420a10f03ccb"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/45xxx/CVE-2026-45983.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-45983","state":"PUBLISHED","datePublished":"2026-05-27T12:18:41.619Z","dateUpdated":"2026-05-27T12:18:41.619Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-05-13T15:03:33.090Z"},"containers":{"cna":{"title":"nfsd: never defer requests during idmap lookup","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: never defer requests during idmap lookup\n\nDuring v4 request compound arg decoding, some ops (e.g. SETATTR)\ncan trigger idmap lookup upcalls. When those upcall responses get\ndelayed beyond the allowed time limit, cache_check() will mark the\nrequest for deferral and cause it to be dropped.\n\nThis prevents nfs4svc_encode_compoundres from being executed, and\nthus the session slot flag NFSD4_SLOT_INUSE never gets cleared.\nSubsequent client requests will fail with NFSERR_JUKEBOX, given\nthat the slot will be marked as in-use, making the SEQUENCE op\nfail.\n\nFix this by making sure that the RQ_USEDEFERRAL flag is always\nclear during nfs4svc_decode_compoundargs(), since no v4 request\nshould ever be deferred."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"2f425878b6a71571341dcd3f9e9d1a6f6355da9c","status":"affected","lessThan":"b9abb760db20504240a7147f27934d900cd80b23","versionType":"git"},{"version":"2f425878b6a71571341dcd3f9e9d1a6f6355da9c","status":"affected","lessThan":"3a72c7dedc99b321e0f267e4e999e5baf07c4593","versionType":"git"},{"version":"2f425878b6a71571341dcd3f9e9d1a6f6355da9c","status":"affected","lessThan":"99e17b20fddac19a228d213e00f6b9e1c10daff9","versionType":"git"},{"version":"2f425878b6a71571341dcd3f9e9d1a6f6355da9c","status":"affected","lessThan":"243f71ed873ff3feeb6f9b5cb145d63f7188b4c4","versionType":"git"},{"version":"2f425878b6a71571341dcd3f9e9d1a6f6355da9c","status":"affected","lessThan":"063a6f22478ef929625000a2caf54667725c1dfd","versionType":"git"},{"version":"2f425878b6a71571341dcd3f9e9d1a6f6355da9c","status":"affected","lessThan":"d75ec4504a4340b033b15cad0303988b3089dd93","versionType":"git"},{"version":"2f425878b6a71571341dcd3f9e9d1a6f6355da9c","status":"affected","lessThan":"8dff54fe88c0dcd4c55bff9fc2fa6ca968290826","versionType":"git"},{"version":"2f425878b6a71571341dcd3f9e9d1a6f6355da9c","status":"affected","lessThan":"f9c206cdc4266caad6a9a7f46341420a10f03ccb","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/nfsd/nfs4idmap.c","fs/nfsd/nfs4proc.c","fs/nfsd/nfs4xdr.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.30","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.30","versionType":"semver"},{"version":"5.10.252","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.202","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.165","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.128","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.75","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.14","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.4","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/nfsd/nfs4idmap.c","fs/nfsd/nfs4proc.c","fs/nfsd/nfs4xdr.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/b9abb760db20504240a7147f27934d900cd80b23"},{"url":"https://git.kernel.org/stable/c/3a72c7dedc99b321e0f267e4e999e5baf07c4593"},{"url":"https://git.kernel.org/stable/c/99e17b20fddac19a228d213e00f6b9e1c10daff9"},{"url":"https://git.kernel.org/stable/c/243f71ed873ff3feeb6f9b5cb145d63f7188b4c4"},{"url":"https://git.kernel.org/stable/c/063a6f22478ef929625000a2caf54667725c1dfd"},{"url":"https://git.kernel.org/stable/c/d75ec4504a4340b033b15cad0303988b3089dd93"},{"url":"https://git.kernel.org/stable/c/8dff54fe88c0dcd4c55bff9fc2fa6ca968290826"},{"url":"https://git.kernel.org/stable/c/f9c206cdc4266caad6a9a7f46341420a10f03ccb"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-27T12:18:41.619Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.30","versionEndExcluding":"5.10.252"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.30","versionEndExcluding":"5.15.202"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.30","versionEndExcluding":"6.1.165"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.30","versionEndExcluding":"6.6.128"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.30","versionEndExcluding":"6.12.75"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.30","versionEndExcluding":"6.18.14"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.30","versionEndExcluding":"6.19.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.30","versionEndExcluding":"7.0"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}