{"id":"CVE-2026-90186","revision":null,"records":[{"revision":"527dfc4558894221bfad0e6fdfb78d1e","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-90186","aliases":[],"title":"null_blk: reject per-device queue resize for shared tag set","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnull_blk: reject per-device queue resize for shared tag set\n\nWhen shared_tags is enabled, null_setup_tagset() makes the device use the\nglobal tag_set, whose driver_data stays NULL. null_map_queues() therefore\nfalls back to the module-wide g_submit_queues/g_poll_queues instead of any\nper-device value.\n\nResizing submit_queues or poll_queues via configfs on such a device calls\nblk_mq_update_nr_hw_queues() on the shared set, shrinking\nset->nr_hw_queues.  __blk_mq_realloc_hw_ctxs() only grows the\nq->queue_hw_ctx[] allocation, so on shrink it merely exits and NULLs the\nnow-excess hctx slots. null_map_queues(), however, keeps mapping CPUs with\nthe unchanged g_submit_queues/g_poll_queues, so mq_map[] ends up pointing\nat those NULLed hctx slots. blk_mq_map_swqueue() then dereferences the NULL\nhctx (hctx->cpumask), crashing the kernel:\n\n[  460.218374] KASAN: null-ptr-deref in range [0x0000000000000098-0x000000000000009f]\n[  460.219003] CPU: 24 UID: 0 PID: 1492 Comm: sh Not tainted 7.2.0-rc2+ #67 PREEMPT(full)\n[  460.219792] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-4.fc41 04/01/2014\n[  460.220452] RIP: 0010:blk_mq_map_swqueue+0x4db/0x1430\n......\n[  460.228977] Call Trace:\n[  460.229175]  <TASK>\n[  460.229354]  blk_mq_update_nr_hw_queues+0xd49/0x11c0\n[  460.229779]  ? __pfx_blk_mq_update_nr_hw_queues+0x10/0x10\n[  460.230200]  nullb_update_nr_hw_queues+0x1a9/0x370 [null_blk]\n[  460.230694]  nullb_device_submit_queues_store+0xd9/0x170 [null_blk]\n[  460.231190]  ? __pfx_nullb_device_submit_queues_store+0x10/0x10 [null_blk]\n[  460.231776]  ? configfs_write_iter+0x35c/0x4e0\n[  460.232122]  configfs_write_iter+0x286/0x4e0\n[  460.232460]  vfs_write+0x52d/0xd00\n[  460.232779]  ? __x64_sys_openat+0x108/0x1d0\n[  460.233106]  ? __pfx_vfs_write+0x10/0x10\n[  460.233413]  ? fdget_pos+0x1cf/0x4c0\n[  460.233745]  ? fput_close+0x133/0x190\n[  460.234038]  ? __pfx_expand_files+0x10/0x10\n[  460.234368]  ksys_write+0xfc/0x1d0\n\nReproducer:\nmodprobe null_blk shared_tags=1 submit_queues=64 poll_queues=1\nmkdir /sys/kernel/config/nullb/dev\necho 1 > /sys/kernel/config/nullb/dev/power\necho 1 > /sys/kernel/config/nullb/dev/submit_queues\n\nA per-device resize of a shared tag set is meaningless anyway, so reject it\nwith -EINVAL in nullb_update_nr_hw_queues() when the device is bound to the\nglobal tag_set.","state":0,"publishedAt":"2026-09-17T16:07:09.047+00:00","modifiedAt":"2026-10-19T08:59:23.057+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                        \"drivers/block/null_blk/main.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"45919fbfe1c487c17ea1d198534339a5e8abeae3\",\n                            \"lessThan\": \"9c7bae099ddc92676ad1b7e29dd6c089e5f6196c\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"45919fbfe1c487c17ea1d198534339a5e8abeae3\",\n                            \"lessThan\": \"fcd53f3e8b758c79c3f2420d28a2a1dce6fda61a\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"45919fbfe1c487c17ea1d198534339a5e8abeae3\",\n                            \"lessThan\": \"f609f7bf9ce8c2fc427705c4a9f623a281239d06\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"45919fbfe1c487c17ea1d198534339a5e8abeae3\",\n                            \"lessThan\": \"3e35ad503386a2e8a0e0460530dcbf421c79f6f2\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"45919fbfe1c487c17ea1d198534339a5e8abeae3\",\n                            \"lessThan\": \"baff300541a0012907cdde349728739fe16176d7\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"45919fbfe1c487c17ea1d198534339a5e8abeae3\",\n                            \"lessThan\": \"1cdfe2fa62b48728a9b436fbbd3dbe4c11593e24\",\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                        \"drivers/block/null_blk/main.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"5.5\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"5.5\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.188\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.157\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.110\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.52\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.6\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/9c7bae099ddc92676ad1b7e29dd6c089e5f6196c","https://git.kernel.org/stable/c/fcd53f3e8b758c79c3f2420d28a2a1dce6fda61a","https://git.kernel.org/stable/c/f609f7bf9ce8c2fc427705c4a9f623a281239d06","https://git.kernel.org/stable/c/3e35ad503386a2e8a0e0460530dcbf421c79f6f2","https://git.kernel.org/stable/c/baff300541a0012907cdde349728739fe16176d7","https://git.kernel.org/stable/c/1cdfe2fa62b48728a9b436fbbd3dbe4c11593e24"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-90186","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-90186","identifiers":["CVE-2026-90186"]},"retained":false,"historicalAffected":[]}],"coverage":[{"source":"cisa-kev:global","scope":"Complete CISA KEV catalog; all vendors. Missing entries do not establish absence of exploitation.","generation":"2026-11-09T03:04:09.5264463+00:00","complete":true,"records":1769,"lastAttemptAt":"2026-11-09T03:04:09.5264463+00:00","lastSuccessAt":"2026-11-09T03:04:09.687719+00:00","error":null,"lastVerifiedAt":"2026-11-09T03:04:09.687725+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"cve-program","scope":"Official CVE Program baseline and cumulative hourly delta; all vendors, published and rejected records","generation":"cve-24e6fde7b744113daefb8f6135035fb8a5c69c9617c9c0d40574a0376532ffd3-147e40e6bacaf605c8b8b91790303c2161fe161e986dcab4007ffaf615b27ea0","complete":true,"records":421280,"lastAttemptAt":"2026-11-09T03:02:14.7184665+00:00","lastSuccessAt":"2026-11-09T03:02:14.7023872+00:00","error":null,"lastVerifiedAt":"2026-11-09T03:02:14.7184665+00:00","snapshotPublishedAt":"2026-11-09T02:22:19+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"euvd","scope":"Rolling EUVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global EUVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-5923d59598fe46c98ec384fbfaf44bc7","complete":false,"records":13654,"lastAttemptAt":"2026-11-09T03:16:18.1412099+00:00","lastSuccessAt":"2026-11-09T03:16:18.138+00:00","error":"6 identifier lookups failed; latest failures include HTTP 403. Other identifiers were checked independently.","lastVerifiedAt":"2026-11-09T03:16:18.138+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13655,"expectedIdentifiers":13706,"failedIdentifiers":6},{"source":"first-epss:nuget","scope":"FIRST EPSS for explicit CVE aliases in the collected public NuGet archive. Not a global EPSS backfill.","generation":"2026-11-09T03:04:09.5264463+00:00","complete":true,"records":1096,"lastAttemptAt":"2026-11-09T03:04:09.5264463+00:00","lastSuccessAt":"2026-11-09T03:04:09.6884561+00:00","error":null,"lastVerifiedAt":"2026-11-09T03:04:09.6884561+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"nvd","scope":"Rolling NVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global NVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-5a44a451442747cb81d83104fe1e7771","complete":true,"records":13666,"lastAttemptAt":"2026-11-09T03:04:10.1662574+00:00","lastSuccessAt":"2026-11-09T02:08:52.274+00:00","error":null,"lastVerifiedAt":"2026-11-09T02:08:52.274+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13706,"expectedIdentifiers":13706,"failedIdentifiers":0},{"source":"osv:Go","scope":"Complete OSV Go ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"go-980593e6977a6d1b4fb1eed5a1ffe88a468736f89f0a06f710924ad59132c023","complete":true,"records":9914,"lastAttemptAt":"2026-11-09T03:04:09.4835743+00:00","lastSuccessAt":"2026-11-08T11:07:07.068788+00:00","error":null,"lastVerifiedAt":"2026-11-09T03:04:09.4835743+00:00","snapshotPublishedAt":"2026-11-08T11:02:46+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:NuGet","scope":"Complete OSV NuGet ecosystem archive, including GitHub Advisory Database records; NuGet version matching only","generation":"nuget-fde804134ecdda0ddd5ff5c26ee1fff5a6fa659311f7ef2e51c6ad54964db0e2","complete":true,"records":1971,"lastAttemptAt":"2026-11-09T03:02:14.8618119+00:00","lastSuccessAt":"2026-11-06T19:03:17.0399903+00:00","error":null,"lastVerifiedAt":"2026-11-09T03:02:14.8618119+00:00","snapshotPublishedAt":"2026-11-06T18:17:57+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:crates.io","scope":"Complete OSV crates.io ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"crates.io-3b1150af6d7ada2c07356cbab4ead5224c1485027890f71c71d0742cddf0b9e8","complete":true,"records":3055,"lastAttemptAt":"2026-11-09T03:04:09.4954044+00:00","lastSuccessAt":"2026-11-09T00:02:23.4330288+00:00","error":null,"lastVerifiedAt":"2026-11-09T03:04:09.4954044+00:00","snapshotPublishedAt":"2026-11-08T23:17:54+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:npm","scope":"Complete OSV npm ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"npm-d847477990cd62b1d95e922f40ca328269fbc268a0aa72bfe5bee28e656d8ce7","complete":true,"records":231296,"lastAttemptAt":"2026-11-09T03:04:09.3500258+00:00","lastSuccessAt":"2026-11-09T03:04:07.965371+00:00","error":null,"lastVerifiedAt":"2026-11-09T03:04:09.3500258+00:00","snapshotPublishedAt":"2026-11-09T02:33:09+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null}]}