CVE-2025-68178

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

blk-cgroup: fix possible deadlock while configuring policy

Following deadlock can be triggered easily by lockdep:

WARNING: possible circular locking dependency detected

6.17.0-rc3-00124-ga12c2658ced0 #1665 Not tainted

------------------------------------------------------

check/1334 is trying to acquire lock:

ff1100011d9d0678 (&q->sysfs_lock){+.+.}-{4:4}, at: blk_unregister_queue+0x53/0x180

but task is already holding lock:

ff1100011d9d00e0 (&q->q_usage_counter(queue)#3){++++}-{0:0}, at: del_gendisk+0xba/0x110

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #2 (&q->q_usage_counter(queue)#3){++++}-{0:0}:

blk_queue_enter+0x40b/0x470

blkg_conf_prep+0x7b/0x3c0

tg_set_limit+0x10a/0x3e0

cgroup_file_write+0xc6/0x420

kernfs_fop_write_iter+0x189/0x280

vfs_write+0x256/0x490

ksys_write+0x83/0x190

__x64_sys_write+0x21

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References