{"id":"CVE-2026-68159","summary":"libceph: bound pg_{temp,upmap,upmap_items} length to CEPH_PG_MAX_SIZE","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nlibceph: bound pg_{temp,upmap,upmap_items} length to CEPH_PG_MAX_SIZE\n\n__decode_pg_temp() decodes an user-controlled length but only rejects\nvalues large enough to overflow the allocation; it does not bound it to\nCEPH_PG_MAX_SIZE. The helper backs both pg_temp and pg_upmap decoding, and\napply_upmap()/get_temp_osds() later copy the decoded list into the fixed-size\non-stack array struct ceph_osds.osds[CEPH_PG_MAX_SIZE]. A monitor that sends\nan OSDMap with a pg_temp/pg_upmap entry longer than 32 thus causes a stack\nout-of-bounds write.\n\nAn OSD set for a single PG can never exceed CEPH_PG_MAX_SIZE, so reject longer\nentries at decode time. The bound is well below the old overflow threshold, so\nit also covers the allocation-size overflow the previous check guarded against.\n\n  BUG: KASAN: stack-out-of-bounds in ceph_pg_to_up_acting_osds\n  Write of size 4 ... by task exploit\n   kasan_report (mm/kasan/report.c:595)\n   ceph_pg_to_up_acting_osds (net/ceph/osdmap.c:2617 net/ceph/osdmap.c:2833)\n   calc_target (net/ceph/osd_client.c:1638)\n   __submit_request (net/ceph/osd_client.c:2394)\n   ceph_osdc_start_request (net/ceph/osd_client.c:2490)\n   ceph_osdc_call (net/ceph/osd_client.c:5164)\n   rbd_dev_image_probe (drivers/block/rbd.c:6899)\n   do_rbd_add (drivers/block/rbd.c:7138)\n   ...\n  kernel BUG at net/ceph/osdmap.c:2670!\n\n[ idryomov: do the same in __decode_pg_upmap_items() ]","modified":"2026-08-24T03:46:17.952681470Z","published":"2026-08-10T11:59:25.697Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68159.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/42bc06c67d94d5f2a6b33294b0c4b07d8a47c515"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4daf06456677177f2a6044729abac59c1b49e87b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/590b07ceea138d49c9b64f65d263aa902d3b4730"},{"type":"WEB","url":"https://git.kernel.org/stable/c/66eec4af1e080b695229c9a20635648a6d12fedf"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9f00f9cf2be293efe899db67dc5272e3a9c62717"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d5650ddbd4d42c1a916c8fe1a4c4cb573ef810a1"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e36663145abd7024f0281dfb22fdef65f185845b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ebdf4b4f3b1474079980a2e5cd79ad65fb54db57"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68159.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-68159"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"a303bb0e58345fe9f7ab2f82b90266f2b5036058"},{"fixed":"66eec4af1e080b695229c9a20635648a6d12fedf"},{"fixed":"4daf06456677177f2a6044729abac59c1b49e87b"},{"fixed":"d5650ddbd4d42c1a916c8fe1a4c4cb573ef810a1"},{"fixed":"42bc06c67d94d5f2a6b33294b0c4b07d8a47c515"},{"fixed":"ebdf4b4f3b1474079980a2e5cd79ad65fb54db57"},{"fixed":"590b07ceea138d49c9b64f65d263aa902d3b4730"},{"fixed":"e36663145abd7024f0281dfb22fdef65f185845b"},{"fixed":"9f00f9cf2be293efe899db67dc5272e3a9c62717"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-68159.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.13.0"},{"fixed":"5.10.266"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.217"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.184"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.153"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.105"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.46"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.6"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-68159.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}