null_blk: use DEFINE_MUTEX for the file-scope mutex
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] [ 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.
CVE-2026-90190
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-90190
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "49c3b9266a718dbd73c42e004288b4bb2ea0ac0b",
"lessThan": "f9f4ca45c770b7eec83fea6c9b727b26e691b513",
"versionType": "git"
},
{
"status": "affected",
"version": "49c3b9266a718dbd73c42e004288b4bb2ea0ac0b",
"lessThan": "349903f7ee72f7ac5b7a98840d701b2082d140a3",
"versionType": "git"
},
{
"status": "affected",
"version": "49c3b9266a718dbd73c42e004288b4bb2ea0ac0b",
"lessThan": "0a8c2f7b95981913ac370683e34db4906970c210",
"versionType": "git"
},
{
"status": "affected",
"version": "49c3b9266a718dbd73c42e004288b4bb2ea0ac0b",
"lessThan": "c7dea90c9b4ef1dfbd2e4df36de180c76fd7c33c",
"versionType": "git"
},
{
"status": "affected",
"version": "49c3b9266a718dbd73c42e004288b4bb2ea0ac0b",
"lessThan": "234117949da3b3f9705a21b66094f9f30bbe681d",
"versionType": "git"
},
{
"status": "affected",
"version": "49c3b9266a718dbd73c42e004288b4bb2ea0ac0b",
"lessThan": "017dac7670909eaea3eb36e6b3b5a8be9ce0a14d",
"versionType": "git"
}
],
"programFiles": [
"drivers/block/null_blk/main.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.19"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.19",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.1.188",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.157",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.110",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.52",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.6",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/block/null_blk/main.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-90190
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #36568 · Revision 1
- Added to Heist Feed
- Publisher date