{"id":"CVE-2026-97564","state":"PUBLISHED","title":"smb: client: reject userspace cifs.idmap descriptions","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: reject userspace cifs.idmap descriptions\n\ncifs.idmap key descriptions carry authority-bearing fields (owner and\ngroup SIDs and uid/gid values in \"os:\"/\"gs:\"/\"oi:\"/\"gi:\" form) that the\ncifs.idmap upcall helper treats as kernel-originating inputs.  Unlike\nits sibling cifs.spnego, the cifs.idmap key type has no vet_description\nhook, so userspace can create keys of this type through\nrequest_key(2)/add_key(2) and supply those fields without CIFS origin.\nA request_key(2) call with a non-NULL callout then drives a root\nusermodehelper upcall (/sbin/request-key -> cifs.idmap) that consumes\nthe unvetted description in root context.\n\nOnly accept cifs.idmap descriptions while CIFS is using its private\nroot_cred to request the key.  id_to_sid()/sid_to_id() already run\nunder override_creds(root_cred), so the kernel-originated path is\nunaffected.\n\nThis mirrors commit 3da1fdf4efbc (\"smb: client: reject userspace\ncifs.spnego descriptions\"), which applied the same restriction to\ncifs.spnego.","publishedAt":"2026-09-25T10:21:51.858Z","updatedAt":"2026-10-30T12:37:26.400Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"4d79dba0e00749fa40de8ef13a9b85ce57a1603b","status":"affected","lessThan":"91da70a2e5c6f54e1316d51e0e6911e78ef5e09a","versionType":"git"},{"version":"4d79dba0e00749fa40de8ef13a9b85ce57a1603b","status":"affected","lessThan":"856cb3f05b49d23dc1542f78696e20c4ea6dd7de","versionType":"git"},{"version":"4d79dba0e00749fa40de8ef13a9b85ce57a1603b","status":"affected","lessThan":"f29c1ec0e7d8c887a91df3f93bb4617c0ac95c6a","versionType":"git"},{"version":"4d79dba0e00749fa40de8ef13a9b85ce57a1603b","status":"affected","lessThan":"17c93bcd17755523c21abb22cbf2a41a6eb0caaf","versionType":"git"},{"version":"4d79dba0e00749fa40de8ef13a9b85ce57a1603b","status":"affected","lessThan":"e5964064e3fbe6325893408faff08ca33de0e2c3","versionType":"git"},{"version":"4d79dba0e00749fa40de8ef13a9b85ce57a1603b","status":"affected","lessThan":"96751028c0d4dec785709ea3eb0ab38a4f2ded96","versionType":"git"},{"version":"4d79dba0e00749fa40de8ef13a9b85ce57a1603b","status":"affected","lessThan":"1d3b24b16a0b013792e8f1e3ed060f0b46f537d1","versionType":"git"},{"version":"4d79dba0e00749fa40de8ef13a9b85ce57a1603b","status":"affected","lessThan":"d9d7eeb0cea5b55b82888f443622fd8d4ee064f3","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/client/cifsacl.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.0","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.0","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":"6.1.189","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.158","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.111","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.53","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.7","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/smb/client/cifsacl.c"]}],"references":["https://git.kernel.org/stable/c/91da70a2e5c6f54e1316d51e0e6911e78ef5e09a","https://git.kernel.org/stable/c/856cb3f05b49d23dc1542f78696e20c4ea6dd7de","https://git.kernel.org/stable/c/f29c1ec0e7d8c887a91df3f93bb4617c0ac95c6a","https://git.kernel.org/stable/c/17c93bcd17755523c21abb22cbf2a41a6eb0caaf","https://git.kernel.org/stable/c/e5964064e3fbe6325893408faff08ca33de0e2c3","https://git.kernel.org/stable/c/96751028c0d4dec785709ea3eb0ab38a4f2ded96","https://git.kernel.org/stable/c/1d3b24b16a0b013792e8f1e3ed060f0b46f537d1","https://git.kernel.org/stable/c/d9d7eeb0cea5b55b82888f443622fd8d4ee064f3"],"weaknesses":[],"ingestedAt":"2026-10-30T12:56:04.490Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/97xxx/CVE-2026-97564.json","commit":"1f312381e38164a43607eebab851b151dd16861e","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-97564","state":"PUBLISHED","datePublished":"2026-09-25T10:21:51.858Z","dateUpdated":"2026-10-30T12:37:26.400Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-24T16:01:01.155Z"},"containers":{"cna":{"title":"smb: client: reject userspace cifs.idmap descriptions","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: reject userspace cifs.idmap descriptions\n\ncifs.idmap key descriptions carry authority-bearing fields (owner and\ngroup SIDs and uid/gid values in \"os:\"/\"gs:\"/\"oi:\"/\"gi:\" form) that the\ncifs.idmap upcall helper treats as kernel-originating inputs.  Unlike\nits sibling cifs.spnego, the cifs.idmap key type has no vet_description\nhook, so userspace can create keys of this type through\nrequest_key(2)/add_key(2) and supply those fields without CIFS origin.\nA request_key(2) call with a non-NULL callout then drives a root\nusermodehelper upcall (/sbin/request-key -> cifs.idmap) that consumes\nthe unvetted description in root context.\n\nOnly accept cifs.idmap descriptions while CIFS is using its private\nroot_cred to request the key.  id_to_sid()/sid_to_id() already run\nunder override_creds(root_cred), so the kernel-originated path is\nunaffected.\n\nThis mirrors commit 3da1fdf4efbc (\"smb: client: reject userspace\ncifs.spnego descriptions\"), which applied the same restriction to\ncifs.spnego."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"4d79dba0e00749fa40de8ef13a9b85ce57a1603b","status":"affected","lessThan":"91da70a2e5c6f54e1316d51e0e6911e78ef5e09a","versionType":"git"},{"version":"4d79dba0e00749fa40de8ef13a9b85ce57a1603b","status":"affected","lessThan":"856cb3f05b49d23dc1542f78696e20c4ea6dd7de","versionType":"git"},{"version":"4d79dba0e00749fa40de8ef13a9b85ce57a1603b","status":"affected","lessThan":"f29c1ec0e7d8c887a91df3f93bb4617c0ac95c6a","versionType":"git"},{"version":"4d79dba0e00749fa40de8ef13a9b85ce57a1603b","status":"affected","lessThan":"17c93bcd17755523c21abb22cbf2a41a6eb0caaf","versionType":"git"},{"version":"4d79dba0e00749fa40de8ef13a9b85ce57a1603b","status":"affected","lessThan":"e5964064e3fbe6325893408faff08ca33de0e2c3","versionType":"git"},{"version":"4d79dba0e00749fa40de8ef13a9b85ce57a1603b","status":"affected","lessThan":"96751028c0d4dec785709ea3eb0ab38a4f2ded96","versionType":"git"},{"version":"4d79dba0e00749fa40de8ef13a9b85ce57a1603b","status":"affected","lessThan":"1d3b24b16a0b013792e8f1e3ed060f0b46f537d1","versionType":"git"},{"version":"4d79dba0e00749fa40de8ef13a9b85ce57a1603b","status":"affected","lessThan":"d9d7eeb0cea5b55b82888f443622fd8d4ee064f3","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/client/cifsacl.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.0","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.0","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":"6.1.189","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.158","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.111","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.53","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.7","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/smb/client/cifsacl.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/91da70a2e5c6f54e1316d51e0e6911e78ef5e09a"},{"url":"https://git.kernel.org/stable/c/856cb3f05b49d23dc1542f78696e20c4ea6dd7de"},{"url":"https://git.kernel.org/stable/c/f29c1ec0e7d8c887a91df3f93bb4617c0ac95c6a"},{"url":"https://git.kernel.org/stable/c/17c93bcd17755523c21abb22cbf2a41a6eb0caaf"},{"url":"https://git.kernel.org/stable/c/e5964064e3fbe6325893408faff08ca33de0e2c3"},{"url":"https://git.kernel.org/stable/c/96751028c0d4dec785709ea3eb0ab38a4f2ded96"},{"url":"https://git.kernel.org/stable/c/1d3b24b16a0b013792e8f1e3ed060f0b46f537d1"},{"url":"https://git.kernel.org/stable/c/d9d7eeb0cea5b55b82888f443622fd8d4ee064f3"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-30T12:37:26.400Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.0","versionEndExcluding":"5.10.273"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.0","versionEndExcluding":"5.15.224"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.0","versionEndExcluding":"6.1.189"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.0","versionEndExcluding":"6.6.158"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.0","versionEndExcluding":"6.12.111"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.0","versionEndExcluding":"6.18.53"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.0","versionEndExcluding":"7.2.7"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.0","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}