CVE-2026-90190null_blk: use DEFINE_MUTEX for the file-scope mutex
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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In the Linux kernel, the following vulnerability has been resolved: null_blk: use DEFINE_MUTEX for the file-scope mutex In null_init(), mutex_init(&lock) currently happens after configfs_register_subsystem(), which exposes the nullb subsystem to userspace. A racing mkdir() into /sys/kernel/config/nullb/ can reach null_find_dev_by_name() -> mutex_lock(&lock) before the mutex is initialized, trigger warning: [ 123.137788] DEBUG_LOCKS_WARN_ON(lock->magic != lock) [ 123.137796] WARNING: kernel/locking/mutex.c:159 at mutex_lock+0x171/0x1c0, CPU#13: mkdir/1301 [ 123.140090] Modules linked in: null_blk(+) nft_fib_inet nft_fib_ipv4 ...... [ 123.154926] Call Trace: [ 123.155172] <TASK> [ 123.155419] ? __pfx_mutex_lock+0x10/0x10 [ 123.156181] ? __pfx__raw_spin_lock+0x10/0x10 [ 123.156571] nullb_group_make_group+0x20/0x100 [null_blk] [ 123.157011] configfs_mkdir+0x47b/0xc70 [ 123.157337] ? __pfx_configfs_mkdir+0x10/0x10 [ 123.157719] ? may_create_dentry+0x242/0x2e0 [ 123.158061] vfs_mkdir+0x2a9/0x6c0 [ 123.158352] filename_mkdirat+0x3dc/0x500 [ 123.158710] ? __pfx_filename_mkdirat+0x10/0x10 [ 123.159070] ? strncpy_from_user+0x3a/0x1d0 [ 123.159413] __x64_sys_mkdir+0x6b/0x90 [ 123.159760] do_syscall_64+0xea/0x600 Replace the runtime mutex_init(&lock) with a static DEFINE_MUTEX(lock) declaration to fix this issue.
- CVSS
- Not yet scored
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Received
- Record last updated
- Sep 17, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from 49c3b9266a718dbd73c42e004288b4bb2ea0ac0b before f9f4ca45c770b7eec83fea6c9b727b26e691b513; from 49c3b9266a718dbd73c42e004288b4bb2ea0ac0b before 349903f7ee72f7ac5b7a98840d701b2082d140a3; 49c3b9266a718dbd73c42e004288b4bb2ea0ac0b builds before 0a8c2f7b95981913ac370683e34db4906970c210; from 49c3b9266a718dbd73c42e004288b4bb2ea0ac0b before c7dea90c9b4ef1dfbd2e4df36de180c76fd7c33c; from 49c3b9266a718dbd73c42e004288b4bb2ea0ac0b before 234117949da3b3f9705a21b66094f9f30bbe681d; 49c3b9266a718dbd73c42e004288b4bb2ea0ac0b builds before 017dac7670909eaea3eb36e6b3b5a8be9ce0a14d | CNA record |
References
- https://git.kernel.org/stable/c/f9f4ca45c770b7eec83fea6c9b727b26e691b513
- https://git.kernel.org/stable/c/349903f7ee72f7ac5b7a98840d701b2082d140a3
- https://git.kernel.org/stable/c/0a8c2f7b95981913ac370683e34db4906970c210
- https://git.kernel.org/stable/c/c7dea90c9b4ef1dfbd2e4df36de180c76fd7c33c
- https://git.kernel.org/stable/c/234117949da3b3f9705a21b66094f9f30bbe681d
- https://git.kernel.org/stable/c/017dac7670909eaea3eb36e6b3b5a8be9ce0a14d
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.