{"id":"CVE-2024-46696","state":"PUBLISHED","title":"nfsd: fix potential UAF in nfsd4_cb_getattr_release","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix potential UAF in nfsd4_cb_getattr_release\n\nOnce we drop the delegation reference, the fields embedded in it are no\nlonger safe to access. Do that last.","publishedAt":"2024-09-13T05:29:24.123Z","updatedAt":"2026-08-05T11:38:01.015Z","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":"c5967721e1063648b0506481585ba7e2e49a075e","status":"affected","lessThan":"e0b66698a5ae41078f7490e8b3527013f5fccd6c","versionType":"git"},{"version":"c5967721e1063648b0506481585ba7e2e49a075e","status":"affected","lessThan":"1116e0e372eb16dd907ec571ce5d4af325c55c10","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/nfsd/nfs4state.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.9","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.9","versionType":"semver"},{"version":"6.10.8","status":"unaffected","lessThanOrEqual":"6.10.*","versionType":"semver"},{"version":"6.11","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/nfsd/nfs4state.c"]}],"references":["https://git.kernel.org/stable/c/e0b66698a5ae41078f7490e8b3527013f5fccd6c","https://git.kernel.org/stable/c/1116e0e372eb16dd907ec571ce5d4af325c55c10"],"weaknesses":[],"ingestedAt":"2026-10-29T20:07:47.831Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2024/46xxx/CVE-2024-46696.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2024-46696","state":"PUBLISHED","datePublished":"2024-09-13T05:29:24.123Z","dateUpdated":"2026-08-05T11:38:01.015Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-09-11T15:12:18.250Z"},"containers":{"cna":{"title":"nfsd: fix potential UAF in nfsd4_cb_getattr_release","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix potential UAF in nfsd4_cb_getattr_release\n\nOnce we drop the delegation reference, the fields embedded in it are no\nlonger safe to access. Do that last."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"c5967721e1063648b0506481585ba7e2e49a075e","status":"affected","lessThan":"e0b66698a5ae41078f7490e8b3527013f5fccd6c","versionType":"git"},{"version":"c5967721e1063648b0506481585ba7e2e49a075e","status":"affected","lessThan":"1116e0e372eb16dd907ec571ce5d4af325c55c10","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/nfsd/nfs4state.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.9","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.9","versionType":"semver"},{"version":"6.10.8","status":"unaffected","lessThanOrEqual":"6.10.*","versionType":"semver"},{"version":"6.11","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/nfsd/nfs4state.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/e0b66698a5ae41078f7490e8b3527013f5fccd6c"},{"url":"https://git.kernel.org/stable/c/1116e0e372eb16dd907ec571ce5d4af325c55c10"}],"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 - The vulnerable path is in the in-kernel NFS server and is driven entirely by NFSv4 COMPOUND requests (OPEN/GETATTR/DELEGRETURN) and the client's CB_GETATTR callback reply over TCP port 2049. No local access to the server is needed.\nAC:L - The attacker controls both sides of the race — the CB_GETATTR reply timing on its own callback channel (the server's wait is a fixed 30 ms timeout that is trivially exceeded on purpose) and the DELEGRETURN that drops the delegation's in-force reference — so it can deterministically arrange for the release callback's put to be the final one.\nPR:N - NFS AUTH_SYS performs no real authentication: any host permitted by the export list simply asserts a uid, and CVSS does not treat network-level export ACLs as privileges. On a typical rw NFSv4 export the attacker needs only to open a file for write and issue a GETATTR from a second clientid, both pre-any-credential-verification.\nUI:N - The attacker drives both the delegation-holding client and the GETATTR-issuing client itself; no action by any legitimate user or administrator is required.\nS:U - The use-after-free corrupts kernel slab memory within the same security authority as the nfsd server; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - A use-after-free on a freed nfs4_delegation gives the attacker, who can groom the reallocation, read access to the reused object — the wake path's test_bit() reads the freed word, and a delegation reused with stale/attacker-adjacent state can leak kernel pointers and file attribute data back over the NFS connection.\nI:H - clear_bit() performs a write into freed slab memory at a fixed offset; since deleg_slab is created with no SLAB_ACCOUNT and no constructor it merges with other same-size caches, turning this into a groomable arbitrary-object bit-clear primitive usable to corrupt flags, counters, or pointer low bits for control-flow hijacking.\nA:H - The use-after-free reliably corrupts freed or reallocated delegation state, causing KASAN-detected UAF, spurious CB_GETATTR re-issue on an in-flight callback, and kernel oops/panic of the NFS file server, which can be triggered repeatedly."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T11:38:01.015Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.9","versionEndExcluding":"6.10.8"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.9","versionEndExcluding":"6.11"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2024-09-29T15:05:32.048367Z","id":"CVE-2024-46696","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2024-09-29T15:05:46.361Z"}}]}}}