{"id":"CVE-2026-80557","revision":"7ee830f218374bd9a31617fe9cc43ead","records":[{"revision":"7ee830f218374bd9a31617fe9cc43ead","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-80557","aliases":[],"title":"libceph: fix OOB read in decode_watchers() via missing bounds check","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nlibceph: fix OOB read in decode_watchers() via missing bounds check\n\nceph_start_decoding() validates that struct_len bytes remain in the\nbuffer after the encoding header, but accepts struct_len=0 as valid:\nceph_decode_need(p, end, 0, bad) always passes. When a malicious or\ncompromised OSD sends an obj_list_watch_response_t reply with\nstruct_len=0, ceph_start_decoding() returns success with p == end,\nleaving zero bytes guaranteed for subsequent reads.\n\nThe immediately following ceph_decode_32(p) in decode_watchers() has\nno preceding bounds check. With p == end this is a 4-byte read past\nthe validated buffer boundary. The garbage value is then passed\ndirectly to kzalloc_objs() as the watcher count.\n\nThe sibling function decode_watcher() already uses the safe variants\n(ceph_decode_copy_safe, ceph_decode_64_safe, ceph_decode_skip_32)\nafter its own ceph_start_decoding() call. decode_watchers() is the\nonly site that uses the bare variant, confirming an oversight.\n\nFix by replacing ceph_decode_32(p) with ceph_decode_32_safe(p, end,\n*num_watchers, bad), consistent with the established pattern.\n\nAttacker model: a malicious or compromised OSD in a multi-tenant Ceph\ndeployment (e.g. cloud) can trigger this against any kernel client\nthat calls CEPH_OSD_OP_LIST_WATCHERS, without any further privileges\nbeyond OSD session establishment.\n\n[ idryomov: trim changelog ]","state":0,"publishedAt":"2026-08-26T14:37:24.178+00:00","modifiedAt":"2026-10-16T19:26:26.946+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/ceph/osd_client.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"a4ed38d7a180f184a6e7aedd09db9ca4b1e6a71c\",\n                            \"lessThan\": \"85479b7d65b4ebcb07fbbe57230976793974ab4a\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"a4ed38d7a180f184a6e7aedd09db9ca4b1e6a71c\",\n                            \"lessThan\": \"1c824e7c75bb4adf19553dd4ea944a5d83096be8\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"a4ed38d7a180f184a6e7aedd09db9ca4b1e6a71c\",\n                            \"lessThan\": \"f161be39201eb5f9b1f58fb8f90b8a9cd3931eb6\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"a4ed38d7a180f184a6e7aedd09db9ca4b1e6a71c\",\n                            \"lessThan\": \"eab3eeb68bfc639d74f27256f05546af5c4f787d\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"a4ed38d7a180f184a6e7aedd09db9ca4b1e6a71c\",\n                            \"lessThan\": \"c59219a6b62d74936963983e5815524c3de8dd79\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"a4ed38d7a180f184a6e7aedd09db9ca4b1e6a71c\",\n                            \"lessThan\": \"cb8246e5846dbbe34930903a90c7a90dd8e5910b\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"a4ed38d7a180f184a6e7aedd09db9ca4b1e6a71c\",\n                            \"lessThan\": \"7130d94846dadbb97b6b7f4d78a3a7bba6e3daa1\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"a4ed38d7a180f184a6e7aedd09db9ca4b1e6a71c\",\n                            \"lessThan\": \"00ead17c7de137a692edee59f2772e6af687e8eb\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/ceph/osd_client.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"4.9\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"4.9\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.267\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.218\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.185\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.154\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.106\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.47\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1.10\",\n                            \"lessThanOrEqual\": \"7.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":9.8,"severity":"CRITICAL"}],"references":["https://git.kernel.org/stable/c/85479b7d65b4ebcb07fbbe57230976793974ab4a","https://git.kernel.org/stable/c/1c824e7c75bb4adf19553dd4ea944a5d83096be8","https://git.kernel.org/stable/c/f161be39201eb5f9b1f58fb8f90b8a9cd3931eb6","https://git.kernel.org/stable/c/eab3eeb68bfc639d74f27256f05546af5c4f787d","https://git.kernel.org/stable/c/c59219a6b62d74936963983e5815524c3de8dd79","https://git.kernel.org/stable/c/cb8246e5846dbbe34930903a90c7a90dd8e5910b","https://git.kernel.org/stable/c/7130d94846dadbb97b6b7f4d78a3a7bba6e3daa1","https://git.kernel.org/stable/c/00ead17c7de137a692edee59f2772e6af687e8eb"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-80557","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-80557","identifiers":["CVE-2026-80557"]},"retained":false,"historicalAffected":[]}],"coverage":[]}