{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-52957","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-06-09T07:44:35.373Z","datePublished":"2026-06-24T16:28:39.066Z","dateUpdated":"2026-08-05T12:32:07.425Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T12:32:07.425Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nlibceph: Fix potential null-ptr-deref in decode_choose_args()\n\nA message of type CEPH_MSG_OSD_MAP contains an OSD map that itself\ncontains a CRUSH map. When decoding this CRUSH map in crush_decode(), an\narray of max_buckets CRUSH buckets is decoded, where some indices may\nnot refer to actual buckets and are therefore set to NULL. The received\nCRUSH map may optionally contain choose_args that get decoded in\ndecode_choose_args(). When decoding a crush_choose_arg_map, a series of\nchoose_args for different buckets is decoded, with the bucket_index\nbeing read from the incoming message. It is only checked that the bucket\nindex does not exceed max_buckets, but not that it doesn't point to an\nindex with a NULL bucket. If a (potentially corrupted) message contains\na crush_choose_arg_map including such a bucket_index, a null pointer\ndereference may occur in the subsequent processing when attempting to\naccess the bucket with the given index.\n\nThis patch fixes the issue by extending the affected check. Now, it is\nonly attempted to access the bucket if it is not NULL."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:N - CEPH_MSG_OSD_MAP is received over Ceph monitor or OSD network connections and decoded by the kernel client. The vulnerable path is network message processing: messenger receive -> ceph_osdc_handle_map() -> ceph_osdmap_decode()/osdmap_apply_incremental() -> crush_decode() -> decode_choose_args().\nAC:L - The attacker-controlled map can directly select a bucket_index within max_buckets whose bucket slot was decoded as NULL and set ids_size nonzero. No race or condition outside the sending peer's control is required.\nPR:N - The message must pass the established Ceph connection/authentication and FSID gates, but a malicious or compromised Ceph peer needs no privileges on the vulnerable Linux system. Auth-none deployments and attacker-controlled Ceph peers make PR:N the highest defensible choice.\nUI:N - Once the kernel client is connected to the Ceph cluster, OSD map updates are processed asynchronously without a user opening a file or performing another action. A malicious peer can send the malformed map as normal cluster traffic.\nS:U - The impact is within the same vulnerable kernel security authority. This is not a VM escape, IOMMU bypass, or cross-scope sandbox escape.\nC:N - The bug is a NULL pointer dereference while reading c->buckets[bucket_index]->size. It does not provide a data disclosure primitive.\nI:N - The vulnerable operation is not a write, UAF, type confusion, or controllable memory corruption. No integrity impact is supported beyond crashing the kernel.\nA:H - Dereferencing the NULL bucket pointer can trigger a kernel oops or panic while processing a malformed OSD/CRUSH map. That is a high availability impact."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ceph/osdmap.c"],"versions":[{"version":"c7ed1a4bf4b446317eefa0f4916d94b1f6d3ada5","lessThan":"d55ffad8d422b5d1cc44dad32bd3d25f4471cd9f","status":"affected","versionType":"git"},{"version":"c7ed1a4bf4b446317eefa0f4916d94b1f6d3ada5","lessThan":"301286c0ccd37d66b0e40786fd35a4f19cdbd88a","status":"affected","versionType":"git"},{"version":"c7ed1a4bf4b446317eefa0f4916d94b1f6d3ada5","lessThan":"7169f326a23d0f547fcd90e68b72fd387622e126","status":"affected","versionType":"git"},{"version":"c7ed1a4bf4b446317eefa0f4916d94b1f6d3ada5","lessThan":"d7a65a34d2453f8cd3e0cc0e1319740af7e24276","status":"affected","versionType":"git"},{"version":"c7ed1a4bf4b446317eefa0f4916d94b1f6d3ada5","lessThan":"312ec973efac0efb9b9ed64214235910e9ecbaa8","status":"affected","versionType":"git"},{"version":"c7ed1a4bf4b446317eefa0f4916d94b1f6d3ada5","lessThan":"f2f95e6d4b97e70bb876139b0583fc8079983f85","status":"affected","versionType":"git"},{"version":"c7ed1a4bf4b446317eefa0f4916d94b1f6d3ada5","lessThan":"a20e16ebfe2fa65348eb4b2dc7deac330ce03e9c","status":"affected","versionType":"git"},{"version":"c7ed1a4bf4b446317eefa0f4916d94b1f6d3ada5","lessThan":"28b0a2ab8c82d0bbdeb8013029c67c978ce6e4bf","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ceph/osdmap.c"],"versions":[{"version":"4.13","status":"affected"},{"version":"0","lessThan":"4.13","status":"unaffected","versionType":"semver"},{"version":"5.10.258","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.209","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.175","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.141","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.91","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.33","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.0.10","lessThanOrEqual":"7.0.*","status":"unaffected","versionType":"semver"},{"version":"7.1","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"5.10.258"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"5.15.209"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"6.1.175"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"6.6.141"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"6.12.91"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"6.18.33"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"7.0.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"7.1"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/d55ffad8d422b5d1cc44dad32bd3d25f4471cd9f"},{"url":"https://git.kernel.org/stable/c/301286c0ccd37d66b0e40786fd35a4f19cdbd88a"},{"url":"https://git.kernel.org/stable/c/7169f326a23d0f547fcd90e68b72fd387622e126"},{"url":"https://git.kernel.org/stable/c/d7a65a34d2453f8cd3e0cc0e1319740af7e24276"},{"url":"https://git.kernel.org/stable/c/312ec973efac0efb9b9ed64214235910e9ecbaa8"},{"url":"https://git.kernel.org/stable/c/f2f95e6d4b97e70bb876139b0583fc8079983f85"},{"url":"https://git.kernel.org/stable/c/a20e16ebfe2fa65348eb4b2dc7deac330ce03e9c"},{"url":"https://git.kernel.org/stable/c/28b0a2ab8c82d0bbdeb8013029c67c978ce6e4bf"}],"title":"libceph: Fix potential null-ptr-deref in decode_choose_args()","x_generator":{"engine":"bippy-1.2.0"}}}}