{"id":"AZL-48962","summary":"CVE-2024-36478 affecting package kernel for versions less than 6.6.57.1-1","details":"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 \u003e submit_queues; echo 4 \u003e submit_queues; done &\nwhile true; do echo 1 \u003e power; echo 0 \u003e 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 \u003cTASK\u003e\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-\u003enullb)\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-\u003enullb = NULL\n\nFix this problem by resuing the global mutex to protect\nnullb_device_power_store() and nullb_update_nr_hw_queues() from configfs.","modified":"2026-04-01T05:16:07.131461Z","published":"2024-06-21T11:15:10Z","upstream":["CVE-2024-36478"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-36478"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.57.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-48962.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}