Improper Locking Affecting kernel-preempt package, versions <5.3.18-150300.59.204.1


Severity

Recommended
0.0
medium
0
10

Based on SUSE Linux Enterprise Server security rating.

Threat Intelligence

EPSS
0.01% (1st percentile)

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  • Snyk IDSNYK-SLES153-KERNELPREEMPT-10223588
  • published22 May 2025
  • disclosed21 May 2025

Introduced: 21 May 2025

NewCVE-2021-47163  (opens in a new tab)
CWE-667  (opens in a new tab)

How to fix?

Upgrade SLES:15.3 kernel-preempt to version 5.3.18-150300.59.204.1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-preempt package and not the kernel-preempt package as distributed by SLES. See How to fix? for SLES:15.3 relevant fixed versions and status.

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

tipc: wait and exit until all work queues are done

On some host, a crash could be triggered simply by repeating these commands several times:

modprobe tipc

tipc bearer enable media udp name UDP1 localip 127.0.0.1

rmmod tipc

[] BUG: unable to handle kernel paging request at ffffffffc096bb00 [] Workqueue: events 0xffffffffc096bb00 [] Call Trace: [] ? process_one_work+0x1a7/0x360 [] ? worker_thread+0x30/0x390 [] ? create_worker+0x1a0/0x1a0 [] ? kthread+0x116/0x130 [] ? kthread_flush_work_fn+0x10/0x10 [] ? ret_from_fork+0x35/0x40

When removing the TIPC module, the UDP tunnel sock will be delayed to release in a work queue as sock_release() can't be done in rtnl_lock(). If the work queue is schedule to run after the TIPC module is removed, kernel will crash as the work queue function cleanup_beareri() code no longer exists when trying to invoke it.

To fix it, this patch introduce a member wq_count in tipc_net to track the numbers of work queues in schedule, and wait and exit until all work queues are done in tipc_exit_net().

CVSS Base Scores

version 3.1