{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-90189", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.792Z", "datePublished": "2026-09-17T16:07:10.992Z", "dateUpdated": "2026-10-19T08:59:25.945Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:59:25.945Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnull_blk: register configfs subsystem after creating default devices\n\nIn null_init(), configfs_register_subsystem() currently runs before\nregister_blkdev(), so when null_blk is built as a module, a racing mkdir()\n+ poweron from userspace can reach null_add_dev() while null_major is still\n0. __add_disk() then hits WARN_ON(disk->minors) (major=0 with minors!=0)\nand fails:\n\n[root@fedora ~]# [ 2366.521436] WARNING: block/genhd.c:476 at __add_disk+0x8a7/0xde0,\n[ 2366.523552] Modules linked in: null_blk(+) nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib\n[ 2366.529081] CPU: 26 UID: 0 PID: 1600 Comm: sh Not tainted 7.2.0-rc1+ #66 PREEMPT(full)\n......\n[ 2366.547251] Call Trace:\n[ 2366.547575] \n[ 2366.547831] ? _raw_spin_lock+0x84/0xe0\n[ 2366.548260] add_disk_fwnode+0x114/0x560\n[ 2366.548739] null_add_dev+0x102d/0x1b80 [null_blk]\n[ 2366.549310] ? __pfx_null_add_dev+0x10/0x10 [null_blk]\n[ 2366.549906] ? mutex_lock+0xde/0x1c0\n[ 2366.550361] ? __pfx_mutex_lock+0x10/0x10\n[ 2366.550827] nullb_device_power_store+0x1e7/0x280 [null_blk]\n[ 2366.551499] ? __pfx_nullb_device_power_store+0x10/0x10 [null_blk]\n[ 2366.552177] ? __kmalloc_cache_noprof+0x1f5/0x470\n[ 2366.552748] ? configfs_write_iter+0x35c/0x4e0\n[ 2366.553242] configfs_write_iter+0x286/0x4e0\n[ 2366.553787] vfs_write+0x52d/0xd00\n[ 2366.554169] ? __pfx_vfs_write+0x10/0x10\n[ 2366.554679] ? __pfx___css_rstat_updated+0x10/0x10\n[ 2366.555196] ? fdget_pos+0x1cf/0x4c0\n[ 2366.555649] ksys_write+0xfc/0x1d0\n......\n\nAdditionally, the err_dev path destroys all devices on nullb_list while\nconfigfs is still registered. If a racing mkdir() + poweron puts a user\ndevice on the list, null_destroy_dev()->null_free_dev() kfrees the user\ndevice's nullb_device but /sys/kernel/config/nullb/ is still\nreachable. Any userspace access to the item will trigger a UAF.\n\nFor simplicity, move configfs_register_subsystem() to the end to solve\nthe problems above." } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/block/null_blk/main.c" ], "versions": [ { "version": "3bf2bd20734e3e6ffda53719a9c10fb3ee9c5ffa", "lessThan": "2679b11e9256bd70a5ef41783bab6ad6c34a3db1", "status": "affected", "versionType": "git" }, { "version": "3bf2bd20734e3e6ffda53719a9c10fb3ee9c5ffa", "lessThan": "dbcedbe4819ae21274ea77469e61e46a878b9943", "status": "affected", "versionType": "git" }, { "version": "3bf2bd20734e3e6ffda53719a9c10fb3ee9c5ffa", "lessThan": "57debc907aef66319d244009d3370dcd97388d37", "status": "affected", "versionType": "git" }, { "version": "3bf2bd20734e3e6ffda53719a9c10fb3ee9c5ffa", "lessThan": "d761be1b8f2bbabc41252deb79a426d3f0d4fa10", "status": "affected", "versionType": "git" }, { "version": "3bf2bd20734e3e6ffda53719a9c10fb3ee9c5ffa", "lessThan": "cab9bf5f68f76cd44e0ec92bd4a60c9b83656a36", "status": "affected", "versionType": "git" }, { "version": "3bf2bd20734e3e6ffda53719a9c10fb3ee9c5ffa", "lessThan": "c9d293d6bb0575fcb1f3408129453187e2a28a4e", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/block/null_blk/main.c" ], "versions": [ { "version": "4.14", "status": "affected" }, { "version": "0", "lessThan": "4.14", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.188", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.157", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.110", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.52", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.6", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "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": "4.14", "versionEndExcluding": "6.1.188" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.14", "versionEndExcluding": "6.6.157" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.14", "versionEndExcluding": "6.12.110" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.14", "versionEndExcluding": "6.18.52" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.14", "versionEndExcluding": "7.2.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.14", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/2679b11e9256bd70a5ef41783bab6ad6c34a3db1" }, { "url": "https://git.kernel.org/stable/c/dbcedbe4819ae21274ea77469e61e46a878b9943" }, { "url": "https://git.kernel.org/stable/c/57debc907aef66319d244009d3370dcd97388d37" }, { "url": "https://git.kernel.org/stable/c/d761be1b8f2bbabc41252deb79a426d3f0d4fa10" }, { "url": "https://git.kernel.org/stable/c/cab9bf5f68f76cd44e0ec92bd4a60c9b83656a36" }, { "url": "https://git.kernel.org/stable/c/c9d293d6bb0575fcb1f3408129453187e2a28a4e" } ], "title": "null_blk: register configfs subsystem after creating default devices", "x_generator": { "engine": "bippy-1.2.0" } } } }