{"api_version":"1","generated_at":"2026-09-25T11:00:36+00:00","cve":"CVE-2026-93229","urls":{"html":"https://cve.report/CVE-2026-93229","api":"https://cve.report/api/cve/CVE-2026-93229.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-93229","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-93229"},"summary":{"title":"nfsd: add missing read barrier to rpc_status_get dumpit seqcount retry","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: add missing read barrier to rpc_status_get dumpit seqcount retry\n\nThe hand-rolled seqcount-like protocol in nfsd_nl_rpc_status_get_dumpit()\nis missing a read memory barrier (smp_rmb) before its second counter\ncheck.  The standard kernel read_seqcount_retry() includes smp_rmb()\nto ensure that all data reads complete before the counter is re-checked.\n\nWithout this barrier, on weakly-ordered architectures (ARM, POWER),\nthe CPU may reorder field reads past the second counter check, making\nthe retry logic ineffective: it could observe a consistent counter pair\nwhile reading fields that have been concurrently modified by the writer.\n\nAdd smp_rmb() before the second counter check to order the field reads\nahead of it, matching the barrier semantics of the standard seqcount\nread-side.  The begin-side smp_load_acquire() already pairs with the\nsmp_store_release() in nfsd_dispatch(); with the smp_rmb() now ordering\nthe field reads, the retry check no longer needs acquire semantics and\nreads the counter with a plain READ_ONCE(), as read_seqcount_retry()\ndoes.\n\n[ cel: Use READ_ONCE instead of smp_load_acquire() ]","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-24 16:17:18","updated_at":"2026-09-25 05:17:00"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"7.1","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","baseScore":7.1,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"NONE","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"7.1","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","data":{"baseScore":7.1,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/f501f2f4ec1d2dfe39e21c98630314074a9b30b0","name":"https://git.kernel.org/stable/c/f501f2f4ec1d2dfe39e21c98630314074a9b30b0","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/a71f161a857117e8e0264deb7d14fff5c98adcf5","name":"https://git.kernel.org/stable/c/a71f161a857117e8e0264deb7d14fff5c98adcf5","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/9b5f6475006cd8e3b5b99b8eb3cd74dbb1ce9df8","name":"https://git.kernel.org/stable/c/9b5f6475006cd8e3b5b99b8eb3cd74dbb1ce9df8","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/1aea0482b98ecd7d0249204665f2ad4ad517f66b","name":"https://git.kernel.org/stable/c/1aea0482b98ecd7d0249204665f2ad4ad517f66b","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-93229","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-93229","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected bd9d6a3efa9709e653aafbeb859289feccb8e70c f501f2f4ec1d2dfe39e21c98630314074a9b30b0 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected bd9d6a3efa9709e653aafbeb859289feccb8e70c 1aea0482b98ecd7d0249204665f2ad4ad517f66b git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected bd9d6a3efa9709e653aafbeb859289feccb8e70c 9b5f6475006cd8e3b5b99b8eb3cd74dbb1ce9df8 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected bd9d6a3efa9709e653aafbeb859289feccb8e70c a71f161a857117e8e0264deb7d14fff5c98adcf5 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.7","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.7 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.109 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.50 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.4 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["fs/nfsd/nfsctl.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"f501f2f4ec1d2dfe39e21c98630314074a9b30b0","status":"affected","version":"bd9d6a3efa9709e653aafbeb859289feccb8e70c","versionType":"git"},{"lessThan":"1aea0482b98ecd7d0249204665f2ad4ad517f66b","status":"affected","version":"bd9d6a3efa9709e653aafbeb859289feccb8e70c","versionType":"git"},{"lessThan":"9b5f6475006cd8e3b5b99b8eb3cd74dbb1ce9df8","status":"affected","version":"bd9d6a3efa9709e653aafbeb859289feccb8e70c","versionType":"git"},{"lessThan":"a71f161a857117e8e0264deb7d14fff5c98adcf5","status":"affected","version":"bd9d6a3efa9709e653aafbeb859289feccb8e70c","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["fs/nfsd/nfsctl.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":"6.12.109","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.50","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.4","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.109","versionStartIncluding":"6.7","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.50","versionStartIncluding":"6.7","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.4","versionStartIncluding":"6.7","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc1","versionStartIncluding":"6.7","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: add missing read barrier to rpc_status_get dumpit seqcount retry\n\nThe hand-rolled seqcount-like protocol in nfsd_nl_rpc_status_get_dumpit()\nis missing a read memory barrier (smp_rmb) before its second counter\ncheck.  The standard kernel read_seqcount_retry() includes smp_rmb()\nto ensure that all data reads complete before the counter is re-checked.\n\nWithout this barrier, on weakly-ordered architectures (ARM, POWER),\nthe CPU may reorder field reads past the second counter check, making\nthe retry logic ineffective: it could observe a consistent counter pair\nwhile reading fields that have been concurrently modified by the writer.\n\nAdd smp_rmb() before the second counter check to order the field reads\nahead of it, matching the barrier semantics of the standard seqcount\nread-side.  The begin-side smp_load_acquire() already pairs with the\nsmp_store_release() in nfsd_dispatch(); with the smp_rmb() now ordering\nthe field reads, the retry check no longer needs acquire semantics and\nreads the counter with a plain READ_ONCE(), as read_seqcount_retry()\ndoes.\n\n[ cel: Use READ_ONCE instead of smp_load_acquire() ]"}],"metrics":[{"cvssV3_1":{"baseScore":7.1,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","version":"3.1"},"scenarios":[{"lang":"en","value":"AV:L - The missing smp_rmb is in nfsd_nl_rpc_status_get_dumpit(), reached only via NFSD_CMD_RPC_STATUS_GET over AF_NETLINK (nfsd_nl_ops dumpit). Remote NFS RPCs in nfsd_dispatch() only write rq_status_counter and never enter dumpit, so exploitation requires local netlink.\nAC:L - The attacker loops NFSD_CMD_RPC_STATUS_GET while sending NFSv4 COMPOUNDs with more than eight ops so nfsd_dispatch() smp_store_release()s rq_status_counter and nfsd4_release_compoundargs() mutates args->ops/opcnt. Both sides of the seqcount race are attacker-driven; weakly-ordered ARM/POWER where the missing smp_rmb matters is mainstream.\nPR:L - NFSD_CMD_RPC_STATUS_GET is registered in nfsd_nl_ops with GENL_CMD_CAP_DUMP and no GENL_ADMIN_PERM, so genl_family_rcv_msg() skips the CAP_NET_ADMIN check. Any unprivileged process in the nfsd network namespace can invoke the dump.\nUI:N - The attacker issues the NFSD_CMD_RPC_STATUS_GET dump and the concurrent NFSv4 COMPOUNDs themselves. No separate victim action such as mounting a filesystem or opening a device is required.\nS:U - The torn and out-of-bounds reads occur in host-kernel nfsd_nl_rpc_status_get_dumpit() on the local machine. Impact stays inside one security authority and is not a VM escape, IOMMU bypass, or other cross-boundary breakout.\nC:H - Without smp_rmb(), dumpit can pass the rq_status_counter retry and still load args->opcnt before nfsd4_release_compoundargs() zeros it and args->ops after it is switched to iops[8]. Indices 8-15 then read adjacent slab at nfsd4_op stride and return those u32s via NFSD_A_RPC_STATUS_COMPOUND_OPS.\nI:N - nfsd_nl_rpc_status_get_dumpit() only copies opnum, xid, addresses and related fields into a stack nfsd_genl_rqstp for netlink. The missing retry barrier yields an out-of-bounds or torn read, not an out-of-bounds write, use-after-free write, or control-flow hijack.\nA:H - Slots 8-15 are sampled at sizeof(struct nfsd4_op) stride past the trailing iops[8] array in kmalloc'd nfsd4_compoundargs into adjacent or unmapped slab pages, which can oops nfsd_nl_rpc_status_get_dumpit() even if the leak is not turned into a stable read."}]}],"providerMetadata":{"dateUpdated":"2026-09-25T05:09:49.321Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/f501f2f4ec1d2dfe39e21c98630314074a9b30b0"},{"url":"https://git.kernel.org/stable/c/1aea0482b98ecd7d0249204665f2ad4ad517f66b"},{"url":"https://git.kernel.org/stable/c/9b5f6475006cd8e3b5b99b8eb3cd74dbb1ce9df8"},{"url":"https://git.kernel.org/stable/c/a71f161a857117e8e0264deb7d14fff5c98adcf5"}],"title":"nfsd: add missing read barrier to rpc_status_get dumpit seqcount retry","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-93229","datePublished":"2026-09-24T15:29:14.322Z","dateReserved":"2026-09-17T16:02:15.094Z","dateUpdated":"2026-09-25T05:09:49.321Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-24 16:17:18","lastModifiedDate":"2026-09-25 05:17:00","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","baseScore":7.1,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":5.2}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"93229","Ordinal":"1","Title":"nfsd: add missing read barrier to rpc_status_get dumpit seqcount","CVE":"CVE-2026-93229","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"93229","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: add missing read barrier to rpc_status_get dumpit seqcount retry\n\nThe hand-rolled seqcount-like protocol in nfsd_nl_rpc_status_get_dumpit()\nis missing a read memory barrier (smp_rmb) before its second counter\ncheck.  The standard kernel read_seqcount_retry() includes smp_rmb()\nto ensure that all data reads complete before the counter is re-checked.\n\nWithout this barrier, on weakly-ordered architectures (ARM, POWER),\nthe CPU may reorder field reads past the second counter check, making\nthe retry logic ineffective: it could observe a consistent counter pair\nwhile reading fields that have been concurrently modified by the writer.\n\nAdd smp_rmb() before the second counter check to order the field reads\nahead of it, matching the barrier semantics of the standard seqcount\nread-side.  The begin-side smp_load_acquire() already pairs with the\nsmp_store_release() in nfsd_dispatch(); with the smp_rmb() now ordering\nthe field reads, the retry check no longer needs acquire semantics and\nreads the counter with a plain READ_ONCE(), as read_seqcount_retry()\ndoes.\n\n[ cel: Use READ_ONCE instead of smp_load_acquire() ]","Type":"Description","Title":"nfsd: add missing read barrier to rpc_status_get dumpit seqcount"}]}}}