CVE-2023-52668

/// Technical description

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

btrfs: zoned: fix lock ordering in btrfs_zone_activate()

The btrfs CI reported a lockdep warning as follows by running generic

generic/129.

WARNING: possible circular locking dependency detected

6.7.0-rc5+ #1 Not tainted

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

kworker/u5:5/793427 is trying to acquire lock:

ffff88813256d028 (&cache->lock){+.+.}-{2:2}, at: btrfs_zone_finish_one_bg+0x5e/0x130

but task is already holding lock:

ffff88810a23a318 (&fs_info->zone_active_bgs_lock){+.+.}-{2:2}, at: btrfs_zone_finish_one_bg+0x34/0x130

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (&fs_info->zone_active_bgs_lock){+.+.}-{2:2}:

...

-> #0 (&cache->lock){+.+.}-{2:2}:

...

This is because we take fs_info->zone_active_bgs_lock after a block_group's

lock in btrfs_zone_activate() while doing the opposite in other places.

Fix

/// 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