{ "schemaVersion": 1, "attribution": [ { "source": "CISA Known Exploited Vulnerabilities", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog", "licence": "US government work" }, { "source": "GitHub Advisory Database", "url": "https://github.com/advisories", "licence": "CC BY 4.0" }, { "source": "Have I Been Pwned", "url": "https://haveibeenpwned.com/", "licence": "CC BY 4.0" }, { "source": "CVE Program (CVE records)", "url": "https://www.cve.org/Legal/TermsOfUse", "licence": "CVE Terms of Use", "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.", "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." }, { "source": "FIRST EPSS", "url": "https://www.first.org/epss/", "licence": "free to use; FIRST requests attribution" } ], "record": { "id": "CVE-2026-90184", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-90184", "idYear": 2026, "status": "PUBLISHED", "publishedAt": "2026-09-17T16:07:07.728Z", "updatedAt": "2026-10-19T08:59:21.103Z", "importedAt": "2026-10-24T01:58:35.090Z", "snapshot": { "id": "cve_2026-10-24_midnight_baseline", "at": "2026-10-24T00:00:00.000Z", "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z" }, "facts": { "title": "null_blk: serialize configfs attribute updates with device setup", "summary": "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().", "affected": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "3bf2bd20734e3e6ffda53719a9c10fb3ee9c5ffa", "status": "affected", "versionType": "git", "lessThan": "6352e7ead2d8111802a554eeb94886f5a9894bb9" }, { "version": "3bf2bd20734e3e6ffda53719a9c10fb3ee9c5ffa", "status": "affected", "versionType": "git", "lessThan": "7de792b4c48fba02a36a8077032f7d5093c925e5" }, { "version": "3bf2bd20734e3e6ffda53719a9c10fb3ee9c5ffa", "status": "affected", "versionType": "git", "lessThan": "aed8af338a09a64d63b068a803c4ecfc5701dd4c" }, { "version": "3bf2bd20734e3e6ffda53719a9c10fb3ee9c5ffa", "status": "affected", "versionType": "git", "lessThan": "32456a85995579e56c60cc53c357cda75a9d4f7c" }, { "version": "3bf2bd20734e3e6ffda53719a9c10fb3ee9c5ffa", "status": "affected", "versionType": "git", "lessThan": "d3d35dd045a35991bf6fd13de5f293e6dd7bf3b3" }, { "version": "3bf2bd20734e3e6ffda53719a9c10fb3ee9c5ffa", "status": "affected", "versionType": "git", "lessThan": "4e1f23f9c33c156be7e313b40695af5a3a834739" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "4.14", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "4.14" }, { "version": "6.1.188", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.1.*" }, { "version": "6.6.157", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.6.*" }, { "version": "6.12.110", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.12.*" }, { "version": "6.18.52", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.18.*" }, { "version": "7.2.6", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "7.2.*" }, { "version": "7.3", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }