What is CVE-2021-47349?

CVE-2021-47349 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, classified as a Improper Locking flaw (CWE-667), affecting Linux kernel versions from 5.12 onward and patched in 5.12.18, 5.13.3 and 5.14. CVE-2021-47349 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2021-47349?

CVE-2021-47349 has a CVSS score of 5.5 out of 10, rated Medium severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Is there a patch available for CVE-2021-47349?

Yes, CVE-2021-47349 has been patched. Fixed versions include 5.12.18, 5.13.3 and 5.14. If you are running Linux kernel 5.12 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2021-47349 actively exploited?

CVE-2021-47349 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is Improper Locking (CWE-667)?

The product does not properly acquire or release a lock, which can lead to unexpected behaviour. See MITRE CWE for full details: https://cwe.mitre.org/data/definitions/667.html

CVE-2021-47349

Medium

In the Linux kernel, the following vulnerability has been resolved: mwifiex: bring down link before deleting interface We can deadlock when rmmod'ing the driver or going through firmware reset, because the cfg80211_unregister_wdev() has to bring down the link for us, ... which then grab the same wiphy lock. nl80211_del_interface() already handles a very similar case, with a nice description: /* * We hold RTNL, so this is safe, without RTNL opencount cannot * reach 0, and thus the rdev cannot be deleted. * * We need to do it for the dev_close(), since that will call * the netdev notifiers, and we need to acquire the mutex there * but don't know if we get there from here or from some other * place (e.g. "ip link set ... down"). */ mutex_unlock(&rdev->wiphy.mtx); ... Do similarly for mwifiex teardown, by ensuring we bring the link down first. Sample deadlock trace: [ 247.103516] INFO: task rmmod:2119 blocked for more than 123 seconds. [ 247.110630] Not tainted 5.12.4 #5 [ 247.115796] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 247.124557] task:rmmod state:D stack: 0 pid: 2119 ppid: 2114 flags:0x00400208 [ 247.133905] Call trace: [ 247.136644] __switch_to+0x130/0x170 [ 247.140643] __schedule+0x714/0xa0c [ 247.144548] schedule_preempt_disabled+0x88/0xf4 [ 247.149714] __mutex_lock_common+0x43c/0x750 [ 247.154496] mutex_lock_nested+0x5c/0x68 [ 247.158884] cfg80211_netdev_notifier_call+0x280/0x4e0 [cfg80211] [ 247.165769] raw_notifier_call_chain+0x4c/0x78 [ 247.170742] call_netdevice_notifiers_info+0x68/0xa4 [ 247.176305] __dev_close_many+0x7c/0x138 [ 247.180693] dev_close_many+0x7c/0x10c [ 247.184893] unregister_netdevice_many+0xfc/0x654 [ 247.190158] unregister_netdevice_queue+0xb4/0xe0 [ 247.195424] _cfg80211_unregister_wdev+0xa4/0x204 [cfg80211] [ 247.201816] cfg80211_unregister_wdev+0x20/0x2c [cfg80211] [ 247.208016] mwifiex_del_virtual_intf+0xc8/0x188 [mwifiex] [ 247.214174] mwifiex_uninit_sw+0x158/0x1b0 [mwifiex] [ 247.219747] mwifiex_remove_card+0x38/0xa0 [mwifiex] [ 247.225316] mwifiex_pcie_remove+0xd0/0xe0 [mwifiex_pcie] [ 247.231451] pci_device_remove+0x50/0xe0 [ 247.235849] device_release_driver_internal+0x110/0x1b0 [ 247.241701] driver_detach+0x5c/0x9c [ 247.245704] bus_remove_driver+0x84/0xb8 [ 247.250095] driver_unregister+0x3c/0x60 [ 247.254486] pci_unregister_driver+0x2c/0x90 [ 247.259267] cleanup_module+0x18/0xcdc [mwifiex_pcie]

Package Linux Kernel

Published 2024-05-21

Last modified 2025-01-10

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

5.5

out of 10

Medium

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

High

Vector string

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness type

CWE-667

CVE-2021-47349 is a Improper Locking vulnerability

What is Improper Locking?

The product does not properly acquire or release a lock, which can lead to unexpected behaviour. Learn more on MITRE CWE

Affected versions

Linux kernel versions 5.12 and later are affected. Fixed in 5.12.18, 5.13.3, 5.14 and their respective stable series.

Affected from

≥ 5.12

Fixed in

✓ 5.12.18 5.12.x ✓ 5.13.3 5.13.x ✓ 5.14

References

3 total

Kernel Git
https://git.kernel.org/stable/c/1f9482aa8d412b4ba06ce6ab8e333fb8ca29a06e

Patch
Kernel Git
https://git.kernel.org/stable/c/35af69c7c0490fdccfc159c6a87e4d1dc070838a

Patch
Kernel Git
https://git.kernel.org/stable/c/a3041d39d3c14da97fa3476835aba043ba810cf0

Patch

Details

CVE ID CVE-2021-47349

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2024-05-21

Modified 2025-01-10

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2021-47349?

CVE-2021-47349 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as an Improper Locking flaw (CWE-667) . It affects Linux kernel versions from 5.12 onward and has been patched in 5.12.18, 5.13.3 and 5.14. CVE-2021-47349 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2021-47349?

CVE-2021-47349 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
Is there a patch available for CVE-2021-47349?

Yes. CVE-2021-47349 has been patched. Fixed versions include 5.12.18, 5.13.3 and 5.14. If you are running Linux kernel 5.12 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2021-47349 actively exploited?

No. CVE-2021-47349 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.