{"api_version":"1","generated_at":"2026-09-13T04:36:18+00:00","cve":"CVE-2026-89649","urls":{"html":"https://cve.report/CVE-2026-89649","api":"https://cve.report/api/cve/CVE-2026-89649.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-89649","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-89649"},"summary":{"title":"ceph: bound xattr value length in __build_xattrs()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nceph: bound xattr value length in __build_xattrs()\n\n__build_xattrs() decodes the MDS-supplied xattr blob one attribute at a\ntime. For each attribute it reads a 32-bit name length, advances past the\nname bytes, reads a 32-bit value length, records the value pointer, and\nadvances past the value bytes. The two length fields are read with\nceph_decode_32_safe(), but the value bytes themselves are advanced over\nwith a bare \"p += len\" and no ceph_decode_need() check that \"len\" bytes\nremain in the blob.\n\nFor every attribute except the last, the next iteration's\nceph_decode_32_safe() on the following name length implicitly verifies\nthat the previous value did not run past the blob end. The final\nattribute has no successor, so its decoded value length is never checked\nagainst the blob bounds. A malicious or compromised metadata server can\nset the last attribute's value length larger than the bytes actually\npresent in the blob.\n\nThe blob is a dedicated kvmalloc() allocation sized to the wire length\n(ceph_buffer_new() in ceph_fill_inode()). __set_xattr() records the\noversized length in xattr->val_len verbatim, and a later getxattr(2) runs\nmemcpy(value, xattr->val, xattr->val_len) into a user-supplied buffer,\ncopying bytes past the end of the allocation back to user space.\n\nImpact: a malicious metadata server discloses adjacent kernel heap bytes\nto a local user via getxattr(2) on a CephFS file. Add the missing\nceph_decode_need() so an out-of-bounds value length on the final\nattribute fails the decode and returns -EIO instead of being stored.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-11 20:19:50","updated_at":"2026-09-11 20:19:50"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/1dd356310b1660215f9a3626580bf8b363ef981e","name":"https://git.kernel.org/stable/c/1dd356310b1660215f9a3626580bf8b363ef981e","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/68d541754d6cd3bb98d1fd8314f57e5eb533557d","name":"https://git.kernel.org/stable/c/68d541754d6cd3bb98d1fd8314f57e5eb533557d","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/b12b3320c81fd72ab36388fb2445fec9c3038f10","name":"https://git.kernel.org/stable/c/b12b3320c81fd72ab36388fb2445fec9c3038f10","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/38be2f3c41ecaba58bb92dc16603e09ba9fd64f1","name":"https://git.kernel.org/stable/c/38be2f3c41ecaba58bb92dc16603e09ba9fd64f1","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89649","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89649","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 355da1eb7a1f91c276b991764e951bbcd8047599 38be2f3c41ecaba58bb92dc16603e09ba9fd64f1 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 355da1eb7a1f91c276b991764e951bbcd8047599 1dd356310b1660215f9a3626580bf8b363ef981e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 355da1eb7a1f91c276b991764e951bbcd8047599 b12b3320c81fd72ab36388fb2445fec9c3038f10 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 355da1eb7a1f91c276b991764e951bbcd8047599 68d541754d6cd3bb98d1fd8314f57e5eb533557d git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 2.6.34","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 2.6.34 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":{"cve_year":"2026","cve_id":"89649","cve":"CVE-2026-89649","epss":"0.001910000","percentile":"0.088850000","score_date":"2026-09-12","updated_at":"2026-09-13 00:08:17"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["fs/ceph/xattr.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"38be2f3c41ecaba58bb92dc16603e09ba9fd64f1","status":"affected","version":"355da1eb7a1f91c276b991764e951bbcd8047599","versionType":"git"},{"lessThan":"1dd356310b1660215f9a3626580bf8b363ef981e","status":"affected","version":"355da1eb7a1f91c276b991764e951bbcd8047599","versionType":"git"},{"lessThan":"b12b3320c81fd72ab36388fb2445fec9c3038f10","status":"affected","version":"355da1eb7a1f91c276b991764e951bbcd8047599","versionType":"git"},{"lessThan":"68d541754d6cd3bb98d1fd8314f57e5eb533557d","status":"affected","version":"355da1eb7a1f91c276b991764e951bbcd8047599","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["fs/ceph/xattr.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"2.6.34"},{"lessThan":"2.6.34","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":"2.6.34","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.50","versionStartIncluding":"2.6.34","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.4","versionStartIncluding":"2.6.34","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc1","versionStartIncluding":"2.6.34","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nceph: bound xattr value length in __build_xattrs()\n\n__build_xattrs() decodes the MDS-supplied xattr blob one attribute at a\ntime. For each attribute it reads a 32-bit name length, advances past the\nname bytes, reads a 32-bit value length, records the value pointer, and\nadvances past the value bytes. The two length fields are read with\nceph_decode_32_safe(), but the value bytes themselves are advanced over\nwith a bare \"p += len\" and no ceph_decode_need() check that \"len\" bytes\nremain in the blob.\n\nFor every attribute except the last, the next iteration's\nceph_decode_32_safe() on the following name length implicitly verifies\nthat the previous value did not run past the blob end. The final\nattribute has no successor, so its decoded value length is never checked\nagainst the blob bounds. A malicious or compromised metadata server can\nset the last attribute's value length larger than the bytes actually\npresent in the blob.\n\nThe blob is a dedicated kvmalloc() allocation sized to the wire length\n(ceph_buffer_new() in ceph_fill_inode()). __set_xattr() records the\noversized length in xattr->val_len verbatim, and a later getxattr(2) runs\nmemcpy(value, xattr->val, xattr->val_len) into a user-supplied buffer,\ncopying bytes past the end of the allocation back to user space.\n\nImpact: a malicious metadata server discloses adjacent kernel heap bytes\nto a local user via getxattr(2) on a CephFS file. Add the missing\nceph_decode_need() so an out-of-bounds value length on the final\nattribute fails the decode and returns -EIO instead of being stored."}],"providerMetadata":{"dateUpdated":"2026-09-11T19:45:40.118Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/38be2f3c41ecaba58bb92dc16603e09ba9fd64f1"},{"url":"https://git.kernel.org/stable/c/1dd356310b1660215f9a3626580bf8b363ef981e"},{"url":"https://git.kernel.org/stable/c/b12b3320c81fd72ab36388fb2445fec9c3038f10"},{"url":"https://git.kernel.org/stable/c/68d541754d6cd3bb98d1fd8314f57e5eb533557d"}],"title":"ceph: bound xattr value length in __build_xattrs()","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-89649","datePublished":"2026-09-11T19:45:40.118Z","dateReserved":"2026-09-11T19:38:34.742Z","dateUpdated":"2026-09-11T19:45:40.118Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-11 20:19:50","lastModifiedDate":"2026-09-11 20:19:50","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"89649","Ordinal":"1","Title":"ceph: bound xattr value length in __build_xattrs()","CVE":"CVE-2026-89649","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"89649","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nceph: bound xattr value length in __build_xattrs()\n\n__build_xattrs() decodes the MDS-supplied xattr blob one attribute at a\ntime. For each attribute it reads a 32-bit name length, advances past the\nname bytes, reads a 32-bit value length, records the value pointer, and\nadvances past the value bytes. The two length fields are read with\nceph_decode_32_safe(), but the value bytes themselves are advanced over\nwith a bare \"p += len\" and no ceph_decode_need() check that \"len\" bytes\nremain in the blob.\n\nFor every attribute except the last, the next iteration's\nceph_decode_32_safe() on the following name length implicitly verifies\nthat the previous value did not run past the blob end. The final\nattribute has no successor, so its decoded value length is never checked\nagainst the blob bounds. A malicious or compromised metadata server can\nset the last attribute's value length larger than the bytes actually\npresent in the blob.\n\nThe blob is a dedicated kvmalloc() allocation sized to the wire length\n(ceph_buffer_new() in ceph_fill_inode()). __set_xattr() records the\noversized length in xattr->val_len verbatim, and a later getxattr(2) runs\nmemcpy(value, xattr->val, xattr->val_len) into a user-supplied buffer,\ncopying bytes past the end of the allocation back to user space.\n\nImpact: a malicious metadata server discloses adjacent kernel heap bytes\nto a local user via getxattr(2) on a CephFS file. Add the missing\nceph_decode_need() so an out-of-bounds value length on the final\nattribute fails the decode and returns -EIO instead of being stored.","Type":"Description","Title":"ceph: bound xattr value length in __build_xattrs()"}]}}}