{"id":"CVE-2026-90184","revision":"142c4fe752844745a017395ef04c6251","records":[{"revision":"142c4fe752844745a017395ef04c6251","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-90184","aliases":[],"title":"null_blk: serialize configfs attribute updates with device setup","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnull_blk: serialize configfs attribute updates with device setup\n\nThe attribute store methods generated with NULLB_DEVICE_ATTR() refuse to\nchange the configuration of a live device by testing\nNULLB_DEV_FL_CONFIGURED, but that flag is only set by\nnullb_device_power_store() after null_add_dev() has returned, and the\nstore methods take no lock at all. configfs only serializes writes to\nthe same open file (buffer->mutex), so a write to any attribute can run\nconcurrently with null_add_dev() and change the device configuration\nwhile it is being used.\n\nnull_add_dev() reads the configuration several times, e.g. dev->zoned is\nread once to set up the queue limits and once to initialize the zone\nresources:\n\n CPU0: echo 1 > nullb0/power CPU1: echo 1 > nullb0/zoned\n nullb_device_power_store()\n mutex_lock(&lock)\n null_add_dev()\n if (dev->zoned) -> false\n /* no BLK_FEAT_ZONED */ nullb_device_zoned_store()\n test_bit(FL_CONFIGURED) -> 0\n dev->zoned = true\n blk_mq_alloc_disk()\n /* queue is not zoned */\n if (nullb->dev->zoned) -> true\n null_register_zoned_dev()\n blk_revalidate_disk_zones()\n\nblk_revalidate_disk_zones() is then called for a queue that does not\nhave BLK_FEAT_ZONED set, which triggers its WARN_ON_ONCE() and fails the\ndevice setup with -EIO:\n\n WARNING: CPU: 2 PID: 322 at block/blk-zoned.c:2357 blk_revalidate_disk_zones+0x4c/0x560\n\nClearing dev->zoned in the same window is worse: the queue is created\nwith BLK_FEAT_ZONED but the zone resources are never initialized, so\nadd_disk() succeeds for a zoned disk that has no zones. And a store that\nlands after the last dev->zoned test leaves dev->zoned set while\ndev->zones is still NULL, which null_process_zoned_cmd() dereferences on\nthe first write.\n\nFix this by taking the global lock, which nullb_device_power_store()\nalready holds across null_add_dev() and null_del_dev(), around both the\nNULLB_DEV_FL_CONFIGURED test and the update of the device configuration.\nThe submit_queues and poll_queues apply callbacks are now called with\nthat lock held, so remove the locking they did themselves.\n\nSince the store methods can run as soon as configfs_register_subsystem()\nreturns, that is, before null_init() gets to mutex_init(&lock), also\ninitialize the lock statically with DEFINE_MUTEX().","state":0,"publishedAt":"2026-09-17T16:07:07.728+00:00","modifiedAt":"2026-10-19T08:59:21.103+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\": \"3bf2bd20734e3e6ffda53719a9c10fb3ee9c5ffa\",\n \"lessThan\": \"6352e7ead2d8111802a554eeb94886f5a9894bb9\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"3bf2bd20734e3e6ffda53719a9c10fb3ee9c5ffa\",\n \"lessThan\": \"7de792b4c48fba02a36a8077032f7d5093c925e5\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"3bf2bd20734e3e6ffda53719a9c10fb3ee9c5ffa\",\n \"lessThan\": \"aed8af338a09a64d63b068a803c4ecfc5701dd4c\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"3bf2bd20734e3e6ffda53719a9c10fb3ee9c5ffa\",\n \"lessThan\": \"32456a85995579e56c60cc53c357cda75a9d4f7c\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"3bf2bd20734e3e6ffda53719a9c10fb3ee9c5ffa\",\n \"lessThan\": \"d3d35dd045a35991bf6fd13de5f293e6dd7bf3b3\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"3bf2bd20734e3e6ffda53719a9c10fb3ee9c5ffa\",\n \"lessThan\": \"4e1f23f9c33c156be7e313b40695af5a3a834739\",\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\": \"4.14\",\n \"status\": \"affected\"\n },\n {\n \"version\": \"0\",\n \"lessThan\": \"4.14\",\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/6352e7ead2d8111802a554eeb94886f5a9894bb9","https://git.kernel.org/stable/c/7de792b4c48fba02a36a8077032f7d5093c925e5","https://git.kernel.org/stable/c/aed8af338a09a64d63b068a803c4ecfc5701dd4c","https://git.kernel.org/stable/c/32456a85995579e56c60cc53c357cda75a9d4f7c","https://git.kernel.org/stable/c/d3d35dd045a35991bf6fd13de5f293e6dd7bf3b3","https://git.kernel.org/stable/c/4e1f23f9c33c156be7e313b40695af5a3a834739"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-90184","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-90184","identifiers":["CVE-2026-90184"]},"retained":false,"historicalAffected":[]}],"coverage":[]}