CVE-2021-47163

tipc: wait and exit until all work queues are done

Published Mar 25, 2024 CVSS 3.1 · 7.8 High EPSS < 1% KEV · Not listed
Description
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().

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Ubuntu USN Ubuntu USN USN-7496-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7496-2 Linux kernel (FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-7496-3 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-7496-4 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-7496-5 Linux kernel (Azure FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-7506-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7506-2 Linux kernel (AWS) vulnerabilities
Ubuntu USN Ubuntu USN USN-7506-3 Linux kernel (FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-7506-4 Linux kernel (Xenial HWE) vulnerabilities
History
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Weaknesses CWE-667
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.13:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.13:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.13:rc3:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
Aug 5, 2026, 8:46 AM
Reserved
Mar 25, 2024, 9:12 AM
Status
Modified
Published
Mar 25, 2024, 10:15 AM
Modified
Aug 4, 2026, 10:16 AM
Severity
Low
Public date
Mar 25, 2024, 12:00 AM