{"api_version":"1","generated_at":"2026-10-03T11:04:44+00:00","cve":"CVE-2026-89990","urls":{"html":"https://cve.report/CVE-2026-89990","api":"https://cve.report/api/cve/CVE-2026-89990.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-89990","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-89990"},"summary":{"title":"ceph: lock mutex in ceph_mds_check_access()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nceph: lock mutex in ceph_mds_check_access()\n\nMDS session OPEN handling replaces mdsc->s_cap_auths under\nmdsc->mutex, freeing the previous array and its strings.\n\nceph_mds_check_access() traverses this array without holding the\nmutex.  A concurrent session reopen can therefore free the array while\nit is being inspected, resulting in a use-after-free like this:\n\n  Unable to handle kernel paging request at virtual address 003aaad64b2c8bb9\n  [...]\n  Internal error: Oops: 0000000096000004 [#1]  SMP\n  Modules linked in:\n  CPU: 56 UID: 2953037534 PID: 1253231 Comm: php-cgi8.4 Not tainted 6.18.45-i2-ampere #1146 NONE\n  [..]\n  pc : ceph_mds_check_access+0xd4/0x550\n  lr : ceph_mds_check_access+0xc8/0x550\n  [...]\n  Call trace:\n   ceph_mds_check_access+0xd4/0x550 (P)\n   ceph_atomic_open+0x138/0xbe8\n   path_openat+0xa24/0xfa8\n   do_filp_open+0x94/0x158\n   do_sys_openat2+0x88/0xf8","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-16 11:17:10","updated_at":"2026-09-16 15:18:22"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"9.8","severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","data":{"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","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"9.8","severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","data":{"baseScore":9.8,"baseSeverity":"CRITICAL","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/df1a97d5313fccadb08390306d49b194fb027392","name":"https://git.kernel.org/stable/c/df1a97d5313fccadb08390306d49b194fb027392","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/729c1ff670ece6f3d4b1738365a0b2f90d487523","name":"https://git.kernel.org/stable/c/729c1ff670ece6f3d4b1738365a0b2f90d487523","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/ca5bfea2045ef2eb3305cf2a9d8da549b76c37d3","name":"https://git.kernel.org/stable/c/ca5bfea2045ef2eb3305cf2a9d8da549b76c37d3","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/a61c6ae1dae2611082b831b4aaa780878099c012","name":"https://git.kernel.org/stable/c/a61c6ae1dae2611082b831b4aaa780878099c012","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89990","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89990","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 596afb0b8933ba6ed7227adcc538db26feb25c74 729c1ff670ece6f3d4b1738365a0b2f90d487523 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 596afb0b8933ba6ed7227adcc538db26feb25c74 ca5bfea2045ef2eb3305cf2a9d8da549b76c37d3 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 596afb0b8933ba6ed7227adcc538db26feb25c74 df1a97d5313fccadb08390306d49b194fb027392 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 596afb0b8933ba6ed7227adcc538db26feb25c74 a61c6ae1dae2611082b831b4aaa780878099c012 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.10","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.10 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.110 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.51 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.5 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3-rc2 * 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/ceph/mds_client.c","fs/ceph/mds_client.h"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"729c1ff670ece6f3d4b1738365a0b2f90d487523","status":"affected","version":"596afb0b8933ba6ed7227adcc538db26feb25c74","versionType":"git"},{"lessThan":"ca5bfea2045ef2eb3305cf2a9d8da549b76c37d3","status":"affected","version":"596afb0b8933ba6ed7227adcc538db26feb25c74","versionType":"git"},{"lessThan":"df1a97d5313fccadb08390306d49b194fb027392","status":"affected","version":"596afb0b8933ba6ed7227adcc538db26feb25c74","versionType":"git"},{"lessThan":"a61c6ae1dae2611082b831b4aaa780878099c012","status":"affected","version":"596afb0b8933ba6ed7227adcc538db26feb25c74","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["fs/ceph/mds_client.c","fs/ceph/mds_client.h"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.10"},{"lessThan":"6.10","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.110","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.51","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.5","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3-rc2","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.110","versionStartIncluding":"6.10","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.51","versionStartIncluding":"6.10","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.5","versionStartIncluding":"6.10","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc2","versionStartIncluding":"6.10","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nceph: lock mutex in ceph_mds_check_access()\n\nMDS session OPEN handling replaces mdsc->s_cap_auths under\nmdsc->mutex, freeing the previous array and its strings.\n\nceph_mds_check_access() traverses this array without holding the\nmutex.  A concurrent session reopen can therefore free the array while\nit is being inspected, resulting in a use-after-free like this:\n\n  Unable to handle kernel paging request at virtual address 003aaad64b2c8bb9\n  [...]\n  Internal error: Oops: 0000000096000004 [#1]  SMP\n  Modules linked in:\n  CPU: 56 UID: 2953037534 PID: 1253231 Comm: php-cgi8.4 Not tainted 6.18.45-i2-ampere #1146 NONE\n  [..]\n  pc : ceph_mds_check_access+0xd4/0x550\n  lr : ceph_mds_check_access+0xc8/0x550\n  [...]\n  Call trace:\n   ceph_mds_check_access+0xd4/0x550 (P)\n   ceph_atomic_open+0x138/0xbe8\n   path_openat+0xa24/0xfa8\n   do_filp_open+0x94/0x158\n   do_sys_openat2+0x88/0xf8"}],"metrics":[{"cvssV3_1":{"baseScore":9.8,"baseSeverity":"CRITICAL","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"scenarios":[{"lang":"en","value":"AV:N - handle_session() frees mdsc->s_cap_auths on CEPH_SESSION_OPEN delivered over the Ceph messenger TCP session (mds_dispatch, CEPH_MSG_CLIENT_SESSION). CephFS re-exported via nfsd/ksmbd also lets a remote client reach the unlocked walker through ceph_atomic_open.\nAC:L - A malicious MDS may send CEPH_SESSION_OPEN even on an already-open session, freeing and replacing s_cap_auths under mdsc->mutex at will. Concurrent open/unlink/setattr, including nfsd/ksmbd on a CephFS export, walk that array without the mutex; the MDS can retry while those operations are in flight.\nPR:N - The attacker is the remote MDS peer, or an NFS/SMB client of a CephFS re-export, and needs no Linux UID, capability, or init-namespace root on the victim host, matching other MDS-driven CephFS client CVEs such as CVE-2026-89651.\nUI:N - Once CephFS is mounted, as is standard in Rook, Kubernetes, and OpenStack, SESSION_OPEN and VFS/nfsd opens run without any further interactive victim action such as mounting media or opening a user-supplied file at exploit time.\nS:U - The use-after-free corrupts kernel heap on the CephFS client host and remains in that kernel's security authority; it is not a VM escape, IOMMU bypass, or sandbox boundary crossing.\nC:H - ceph_mds_check_access() and ceph_mds_auth_match() dereference the freed s_cap_auths array and its match.path, gids, and fs_name strings; a use-after-free of those objects enables arbitrary kernel read via heap reuse and is High per kernel UAF guidance.\nI:H - The same UAF is heap-sprayable with attacker-controlled SESSION_OPEN allocations (cap_auths_num and string lengths), yielding write and control-flow primitives; kernel guidance scores use-after-free integrity as High.\nA:H - The reported oops is a kernel paging fault in ceph_mds_check_access from ceph_atomic_open on the freed array; repeating SESSION_OPEN while the walker runs can oops or panic the client, which is High availability impact."}]}],"providerMetadata":{"dateUpdated":"2026-09-16T14:41:05.472Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/729c1ff670ece6f3d4b1738365a0b2f90d487523"},{"url":"https://git.kernel.org/stable/c/ca5bfea2045ef2eb3305cf2a9d8da549b76c37d3"},{"url":"https://git.kernel.org/stable/c/df1a97d5313fccadb08390306d49b194fb027392"},{"url":"https://git.kernel.org/stable/c/a61c6ae1dae2611082b831b4aaa780878099c012"}],"title":"ceph: lock mutex in ceph_mds_check_access()","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-89990","datePublished":"2026-09-16T10:33:04.371Z","dateReserved":"2026-09-11T19:38:34.780Z","dateUpdated":"2026-09-16T14:41:05.472Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-16 11:17:10","lastModifiedDate":"2026-09-16 15:18:22","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"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","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":3.9,"impactScore":5.9}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"89990","Ordinal":"1","Title":"ceph: lock mutex in ceph_mds_check_access()","CVE":"CVE-2026-89990","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"89990","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nceph: lock mutex in ceph_mds_check_access()\n\nMDS session OPEN handling replaces mdsc->s_cap_auths under\nmdsc->mutex, freeing the previous array and its strings.\n\nceph_mds_check_access() traverses this array without holding the\nmutex.  A concurrent session reopen can therefore free the array while\nit is being inspected, resulting in a use-after-free like this:\n\n  Unable to handle kernel paging request at virtual address 003aaad64b2c8bb9\n  [...]\n  Internal error: Oops: 0000000096000004 [#1]  SMP\n  Modules linked in:\n  CPU: 56 UID: 2953037534 PID: 1253231 Comm: php-cgi8.4 Not tainted 6.18.45-i2-ampere #1146 NONE\n  [..]\n  pc : ceph_mds_check_access+0xd4/0x550\n  lr : ceph_mds_check_access+0xc8/0x550\n  [...]\n  Call trace:\n   ceph_mds_check_access+0xd4/0x550 (P)\n   ceph_atomic_open+0x138/0xbe8\n   path_openat+0xa24/0xfa8\n   do_filp_open+0x94/0x158\n   do_sys_openat2+0x88/0xf8","Type":"Description","Title":"ceph: lock mutex in ceph_mds_check_access()"}]}}}