{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-68159","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-07-30T09:28:09.371Z","datePublished":"2026-08-10T11:59:25.697Z","dateUpdated":"2026-08-23T12:46:00.131Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-23T12:46:00.131Z"},"descriptions":[{"lang":"en","value":"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() ]"}],"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 - Malicious pg_temp/pg_upmap data arrives in CEPH_MSG_OSD_MAP from a Ceph monitor or OSD over TCP, is decoded in libceph, and later triggers stack corruption in ceph_pg_to_up_acting_osds during RBD/CephFS/libceph client I/O.\nAC:L - A compromised or attacker-controlled monitor can publish osdmap entries with length >32 for chosen PGs; once the client subscribes, kernel I/O paths such as RBD mount/probe via calc_target deterministically invoke apply_upmap/get_temp_osds and overflow the stack buffer.\nPR:N - Exploitation requires no privileges on the victim host; any machine acting as a Ceph client that receives a forged osdmap from a cluster peer over the network can be attacked without local user capabilities or namespace tricks.\nUI:N - No victim user action is needed during exploitation beyond the host already being a Ceph client; forged osdmaps are applied automatically and the overflow fires on subsequent kernel client operations without interactive steps.\nS:U - Impact is confined to kernel memory on the Ceph client host (privilege escalation or crash); it does not cross VM, IOMMU, or sandbox boundaries to other security authorities.\nC:H - KASAN-confirmed stack out-of-bounds write in ceph_pg_to_up_acting_osds corrupts adjacent stack memory and can be leveraged for arbitrary kernel memory disclosure, not merely a bounded leak.\nI:H - Unbounded copy loops in apply_upmap() and get_temp_osds() write attacker-controlled u32 OSD IDs past the fixed osds[CEPH_PG_MAX_SIZE] stack array, enabling control-flow hijack and arbitrary kernel writes.\nA:H - The reported reproducer triggers KASAN stack-out-of-bounds followed by kernel BUG in ceph_pg_to_up_acting_osds, demonstrating a reliable kernel oops or panic from malformed osdmap processing on Ceph clients."}]}],"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":"a303bb0e58345fe9f7ab2f82b90266f2b5036058","lessThan":"66eec4af1e080b695229c9a20635648a6d12fedf","status":"affected","versionType":"git"},{"version":"a303bb0e58345fe9f7ab2f82b90266f2b5036058","lessThan":"4daf06456677177f2a6044729abac59c1b49e87b","status":"affected","versionType":"git"},{"version":"a303bb0e58345fe9f7ab2f82b90266f2b5036058","lessThan":"d5650ddbd4d42c1a916c8fe1a4c4cb573ef810a1","status":"affected","versionType":"git"},{"version":"a303bb0e58345fe9f7ab2f82b90266f2b5036058","lessThan":"42bc06c67d94d5f2a6b33294b0c4b07d8a47c515","status":"affected","versionType":"git"},{"version":"a303bb0e58345fe9f7ab2f82b90266f2b5036058","lessThan":"ebdf4b4f3b1474079980a2e5cd79ad65fb54db57","status":"affected","versionType":"git"},{"version":"a303bb0e58345fe9f7ab2f82b90266f2b5036058","lessThan":"590b07ceea138d49c9b64f65d263aa902d3b4730","status":"affected","versionType":"git"},{"version":"a303bb0e58345fe9f7ab2f82b90266f2b5036058","lessThan":"e36663145abd7024f0281dfb22fdef65f185845b","status":"affected","versionType":"git"},{"version":"a303bb0e58345fe9f7ab2f82b90266f2b5036058","lessThan":"9f00f9cf2be293efe899db67dc5272e3a9c62717","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":"5.10.266","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.217","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.184","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.153","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.105","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.46","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.1.6","lessThanOrEqual":"7.1.*","status":"unaffected","versionType":"semver"},{"version":"7.2","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":"5.10.266"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"5.15.217"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"6.1.184"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"6.6.153"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"6.12.105"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"6.18.46"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"7.1.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"7.2"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/66eec4af1e080b695229c9a20635648a6d12fedf"},{"url":"https://git.kernel.org/stable/c/4daf06456677177f2a6044729abac59c1b49e87b"},{"url":"https://git.kernel.org/stable/c/d5650ddbd4d42c1a916c8fe1a4c4cb573ef810a1"},{"url":"https://git.kernel.org/stable/c/42bc06c67d94d5f2a6b33294b0c4b07d8a47c515"},{"url":"https://git.kernel.org/stable/c/ebdf4b4f3b1474079980a2e5cd79ad65fb54db57"},{"url":"https://git.kernel.org/stable/c/590b07ceea138d49c9b64f65d263aa902d3b4730"},{"url":"https://git.kernel.org/stable/c/e36663145abd7024f0281dfb22fdef65f185845b"},{"url":"https://git.kernel.org/stable/c/9f00f9cf2be293efe899db67dc5272e3a9c62717"}],"title":"libceph: bound pg_{temp,upmap,upmap_items} length to CEPH_PG_MAX_SIZE","x_generator":{"engine":"bippy-1.2.0"}}}}