{"cve":"CVE-2024-36478","nvd":{"published":"2024-06-21T11:15:10.360","modified":"2026-06-17T07:36:48.410","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnull_blk: fix null-ptr-dereference while configuring 'power' and 'submit_queues'\n\nWriting 'power' and 'submit_queues' concurrently will trigger kernel\npanic:\n\nTest script:\n\nmodprobe null_blk nr_devices=0\nmkdir -p /sys/kernel/config/nullb/nullb0\nwhile true; do echo 1 > submit_queues; echo 4 > submit_queues; done &\nwhile true; do echo 1 > power; echo 0 > power; done\n\nTest result:\n\nBUG: kernel NULL pointer dereference, address: 0000000000000148\nOops: 0000 [#1] PREEMPT SMP\nRIP: 0010:__lock_acquire+0x41d/0x28f0\nCall Trace:\n <TASK>\n lock_acquire+0x121/0x450\n down_write+0x5f/0x1d0\n simple_recursive_removal+0x12f/0x5c0\n blk_mq_debugfs_unregister_hctxs+0x7c/0x100\n blk_mq_update_nr_hw_queues+0x4a3/0x720\n nullb_update_nr_hw_queues+0x71/0xf0 [null_blk]\n nullb_device_submit_queues_store+0x79/0xf0 [null_blk]\n configfs_write_iter+0x119/0x1e0\n vfs_write+0x326/0x730\n ksys_write+0x74/0x150\n\nThis is because del_gendisk() can concurrent with\nblk_mq_update_nr_hw_queues():\n\nnullb_device_power_store\tnullb_apply_submit_queues\n null_del_dev\n del_gendisk\n\t\t\t\t nullb_update_nr_hw_queues\n\t\t\t\t  if (!dev->nullb)\n\t\t\t\t  // still set while gendisk is deleted\n\t\t\t\t   return 0\n\t\t\t\t  blk_mq_update_nr_hw_queues\n dev->nullb = NULL\n\nFix this problem by resuing the global mutex to protect\nnullb_device_power_store() and nullb_update_nr_hw_queues() from configfs.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-476"],"references":["https://git.kernel.org/stable/c/1d4c8baef435c98e8d5aa7027dc5a9f70834ba16","https://git.kernel.org/stable/c/5d0495473ee4c1d041b5a917f10446a22c047f47","https://git.kernel.org/stable/c/a2db328b0839312c169eb42746ec46fc1ab53ed2","https://git.kernel.org/stable/c/aaadb755f2d684f715a6eb85cb7243aa0c67dfa9","https://git.kernel.org/stable/c/5d0495473ee4c1d041b5a917f10446a22c047f47"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:52:00.836172422+00:00"},"epss":{"cve":"CVE-2024-36478","score":0.00266,"percentile":0.18807,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}