{"id":"CVE-2026-89652","state":"PUBLISHED","title":"ceph: bound copied dentry name length in NFS export get_name","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nceph: bound copied dentry name length in NFS export get_name\n\nceph_get_name() copies the MDS-supplied name into the caller's\nNAME_MAX-sized buffer with memcpy(name, rinfo->dname, rinfo->dname_len)\nand then writes name[rinfo->dname_len] = 0, without checking dname_len\nagainst NAME_MAX. A malicious or buggy MDS that returns a LOOKUPNAME reply\nwith dname_len > NAME_MAX overflows the buffer. __get_snap_name() copies\nrde->name / rde->name_len the same unchecked way.\n\nImpact: a malicious or compromised Ceph MDS overflows the NAME_MAX name\nbuffer in a client's NFS-export get_name path, a slab out-of-bounds write\nreported by KASAN. Reachable when a CephFS mount is re-exported over NFS.\n\nAdd ceph_export_copy_name(), which rejects lengths above NAME_MAX with\n-ENAMETOOLONG before the copy, and use it in both ceph_get_name() and\n__get_snap_name().","publishedAt":"2026-09-11T19:45:42.443Z","updatedAt":"2026-10-30T12:32:32.345Z","severity":{"score":9.8,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"19913b4eac4a230dccb548931358398f45dabe4c","status":"affected","lessThan":"aadfe588ad8032ea99bda259ae7b8d42854f8193","versionType":"git"},{"version":"19913b4eac4a230dccb548931358398f45dabe4c","status":"affected","lessThan":"3cb09301c30909a7935e9de41f98eeb5ef7e4d40","versionType":"git"},{"version":"19913b4eac4a230dccb548931358398f45dabe4c","status":"affected","lessThan":"dff3d84d14142ea43ad61ef5d6b4de05ba16ba42","versionType":"git"},{"version":"19913b4eac4a230dccb548931358398f45dabe4c","status":"affected","lessThan":"a294064e0e0f81ea607b2f019e16888aa1b0a011","versionType":"git"},{"version":"19913b4eac4a230dccb548931358398f45dabe4c","status":"affected","lessThan":"61d9f27b191b838b96b697ce0bfaee39a138243a","versionType":"git"},{"version":"19913b4eac4a230dccb548931358398f45dabe4c","status":"affected","lessThan":"06fb5e623cdc2402d6bb29be94d9beb9a826ffec","versionType":"git"},{"version":"19913b4eac4a230dccb548931358398f45dabe4c","status":"affected","lessThan":"e7c2fd3893a7f7fcd7e8cf0b2c6348bb1e893df6","versionType":"git"},{"version":"19913b4eac4a230dccb548931358398f45dabe4c","status":"affected","lessThan":"eff8013c5a8916613c742ae5a2cc341cb605c0ae","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ceph/export.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.15","versionType":"semver"},{"version":"5.10.273","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.224","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.157","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.109","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.50","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.4","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ceph/export.c"]}],"references":["https://git.kernel.org/stable/c/aadfe588ad8032ea99bda259ae7b8d42854f8193","https://git.kernel.org/stable/c/3cb09301c30909a7935e9de41f98eeb5ef7e4d40","https://git.kernel.org/stable/c/dff3d84d14142ea43ad61ef5d6b4de05ba16ba42","https://git.kernel.org/stable/c/a294064e0e0f81ea607b2f019e16888aa1b0a011","https://git.kernel.org/stable/c/61d9f27b191b838b96b697ce0bfaee39a138243a","https://git.kernel.org/stable/c/06fb5e623cdc2402d6bb29be94d9beb9a826ffec","https://git.kernel.org/stable/c/e7c2fd3893a7f7fcd7e8cf0b2c6348bb1e893df6","https://git.kernel.org/stable/c/eff8013c5a8916613c742ae5a2cc341cb605c0ae"],"weaknesses":[],"ingestedAt":"2026-10-30T12:50:04.827Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/89xxx/CVE-2026-89652.json","commit":"1f312381e38164a43607eebab851b151dd16861e","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-89652","state":"PUBLISHED","datePublished":"2026-09-11T19:45:42.443Z","dateUpdated":"2026-10-30T12:32:32.345Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-11T19:38:34.742Z"},"containers":{"cna":{"title":"ceph: bound copied dentry name length in NFS export get_name","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nceph: bound copied dentry name length in NFS export get_name\n\nceph_get_name() copies the MDS-supplied name into the caller's\nNAME_MAX-sized buffer with memcpy(name, rinfo->dname, rinfo->dname_len)\nand then writes name[rinfo->dname_len] = 0, without checking dname_len\nagainst NAME_MAX. A malicious or buggy MDS that returns a LOOKUPNAME reply\nwith dname_len > NAME_MAX overflows the buffer. __get_snap_name() copies\nrde->name / rde->name_len the same unchecked way.\n\nImpact: a malicious or compromised Ceph MDS overflows the NAME_MAX name\nbuffer in a client's NFS-export get_name path, a slab out-of-bounds write\nreported by KASAN. Reachable when a CephFS mount is re-exported over NFS.\n\nAdd ceph_export_copy_name(), which rejects lengths above NAME_MAX with\n-ENAMETOOLONG before the copy, and use it in both ceph_get_name() and\n__get_snap_name()."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"19913b4eac4a230dccb548931358398f45dabe4c","status":"affected","lessThan":"aadfe588ad8032ea99bda259ae7b8d42854f8193","versionType":"git"},{"version":"19913b4eac4a230dccb548931358398f45dabe4c","status":"affected","lessThan":"3cb09301c30909a7935e9de41f98eeb5ef7e4d40","versionType":"git"},{"version":"19913b4eac4a230dccb548931358398f45dabe4c","status":"affected","lessThan":"dff3d84d14142ea43ad61ef5d6b4de05ba16ba42","versionType":"git"},{"version":"19913b4eac4a230dccb548931358398f45dabe4c","status":"affected","lessThan":"a294064e0e0f81ea607b2f019e16888aa1b0a011","versionType":"git"},{"version":"19913b4eac4a230dccb548931358398f45dabe4c","status":"affected","lessThan":"61d9f27b191b838b96b697ce0bfaee39a138243a","versionType":"git"},{"version":"19913b4eac4a230dccb548931358398f45dabe4c","status":"affected","lessThan":"06fb5e623cdc2402d6bb29be94d9beb9a826ffec","versionType":"git"},{"version":"19913b4eac4a230dccb548931358398f45dabe4c","status":"affected","lessThan":"e7c2fd3893a7f7fcd7e8cf0b2c6348bb1e893df6","versionType":"git"},{"version":"19913b4eac4a230dccb548931358398f45dabe4c","status":"affected","lessThan":"eff8013c5a8916613c742ae5a2cc341cb605c0ae","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ceph/export.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.15","versionType":"semver"},{"version":"5.10.273","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.224","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.157","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.109","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.50","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.4","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ceph/export.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/aadfe588ad8032ea99bda259ae7b8d42854f8193"},{"url":"https://git.kernel.org/stable/c/3cb09301c30909a7935e9de41f98eeb5ef7e4d40"},{"url":"https://git.kernel.org/stable/c/dff3d84d14142ea43ad61ef5d6b4de05ba16ba42"},{"url":"https://git.kernel.org/stable/c/a294064e0e0f81ea607b2f019e16888aa1b0a011"},{"url":"https://git.kernel.org/stable/c/61d9f27b191b838b96b697ce0bfaee39a138243a"},{"url":"https://git.kernel.org/stable/c/06fb5e623cdc2402d6bb29be94d9beb9a826ffec"},{"url":"https://git.kernel.org/stable/c/e7c2fd3893a7f7fcd7e8cf0b2c6348bb1e893df6"},{"url":"https://git.kernel.org/stable/c/eff8013c5a8916613c742ae5a2cc341cb605c0ae"}],"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 - ceph_get_name() copies LOOKUPNAME/LSSNAP dentry names from a Ceph MDS reply over TCP, and nfsd reaches that callback via exportfs_decode_fh_raw() when CephFS is re-exported, so a remote MDS (or NFS client against such a gateway) hits the overflow on the network path.\nAC:L - A malicious MDS fully controls dname_len and the name bytes. nfsd lookup of a Ceph directory uses d_obtain_alias() then reconnect_path(), which deterministically calls get_name; no race, rare config, or uncontrollable layout is required.\nPR:N - No local account or capability on the victim is needed. A compromised or malicious MDS supplies the overflowing name, and on NFS-reexported CephFS any remote NFS client can force LOOKUPNAME by presenting a directory filehandle.\nUI:N - Once CephFS is mounted and re-exported over NFS, nfsd directory filehandle resolution automatically issues LOOKUPNAME and copies the MDS reply; no extra victim mount, click, or interactive step is required at exploit time.\nS:U - The overflow corrupts kernel stack/memory on the NFS/Ceph client host and does not cross a VM, IOMMU, or other security-authority boundary.\nC:H - Unbounded memcpy of MDS-controlled name bytes past the NAME_MAX+1 exportfs buffer is memory corruption that can overwrite adjacent kernel objects and be leveraged for arbitrary disclosure.\nI:H - Attacker-controlled length and contents overflow the NAME_MAX+1 stack buffer in exportfs_decode_fh_raw(), enabling an arbitrary write and control-flow hijacking.\nA:H - The same out-of-bounds write of a 256-byte name buffer by an MDS-chosen length, reported as a KASAN OOB write, reliably oopses or panics the kernel."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-30T12:32:32.345Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.15","versionEndExcluding":"5.10.273"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.15","versionEndExcluding":"5.15.224"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.15","versionEndExcluding":"6.1.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.15","versionEndExcluding":"6.6.157"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.15","versionEndExcluding":"6.12.109"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.15","versionEndExcluding":"6.18.50"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.15","versionEndExcluding":"7.2.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.15","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-89652","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T19:25:18.510719Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-16T19:26:46.828Z"}}]}}}