CVE-2023-52668

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 the issue by expanding the fs_info->zone_active_bgs_lock's critical section and taking it before a block_group's lock.

CVSS Metrics

• v3.1•MEDIUM•Score: 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Trends

Current EPSS score: 0.01%• Percentile: 2%

Techniques & Countermeasures

• CWE-667•Improper Locking

  The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.

Affected Systems

• linux•linux

  ≥ a7e1ac7bdc5af91af2d52e6269fdbd92fe9ee353, < 6f74989f5909cdec9b1274641f0fa306b15bb476 | ≥ a7e1ac7bdc5af91af2d52e6269fdbd92fe9ee353, < 1908e9d01e5395adff68d9d308a0fb15337e6272 | ≥ a7e1ac7bdc5af91af2d52e6269fdbd92fe9ee353, < b18f3b60b35a8c01c9a2a0f0d6424c6d73971dc3 | 6.6

• linux•linux_kernel

  ≥ 6.6, < 6.6.15 | ≥ 6.7, < 6.7.3 | 6.8:rc1

References (3)

• https://git.kernel.org/stable/c/6f74989f5909cdec9b1274641f0fa306b15bb476
• https://git.kernel.org/stable/c/1908e9d01e5395adff68d9d308a0fb15337e6272
• https://git.kernel.org/stable/c/b18f3b60b35a8c01c9a2a0f0d6424c6d73971dc3