{"id":"AZL-102345","summary":"CVE-2026-90190 affecting package kernel 6.6.150.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnull_blk: use DEFINE_MUTEX for the file-scope mutex\n\nIn null_init(), mutex_init(&lock) currently happens after\nconfigfs_register_subsystem(), which exposes the nullb subsystem to\nuserspace. A racing mkdir() into /sys/kernel/config/nullb/ can reach\nnull_find_dev_by_name() -\u003e mutex_lock(&lock) before the mutex is\ninitialized, trigger warning:\n\n[  123.137788] DEBUG_LOCKS_WARN_ON(lock-\u003emagic != lock)\n[  123.137796] WARNING: kernel/locking/mutex.c:159 at mutex_lock+0x171/0x1c0, CPU#13: mkdir/1301\n[  123.140090] Modules linked in: null_blk(+) nft_fib_inet nft_fib_ipv4\n......\n[  123.154926] Call Trace:\n[  123.155172]  \u003cTASK\u003e\n[  123.155419]  ? __pfx_mutex_lock+0x10/0x10\n[  123.156181]  ? __pfx__raw_spin_lock+0x10/0x10\n[  123.156571]  nullb_group_make_group+0x20/0x100 [null_blk]\n[  123.157011]  configfs_mkdir+0x47b/0xc70\n[  123.157337]  ? __pfx_configfs_mkdir+0x10/0x10\n[  123.157719]  ? may_create_dentry+0x242/0x2e0\n[  123.158061]  vfs_mkdir+0x2a9/0x6c0\n[  123.158352]  filename_mkdirat+0x3dc/0x500\n[  123.158710]  ? __pfx_filename_mkdirat+0x10/0x10\n[  123.159070]  ? strncpy_from_user+0x3a/0x1d0\n[  123.159413]  __x64_sys_mkdir+0x6b/0x90\n[  123.159760]  do_syscall_64+0xea/0x600\n\nReplace the runtime mutex_init(&lock) with a static DEFINE_MUTEX(lock)\ndeclaration to fix this issue.","modified":"2026-09-18T14:17:50.092143599Z","published":"2026-09-17T17:17:13Z","upstream":["CVE-2026-90190"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-90190"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"6.6.150.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-102345.json"}}],"schema_version":"1.9.0"}