What is CVE-2021-47468?

CVE-2021-47468 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 2.6.32 onward and patched in 4.4.290, 4.9.288, 4.14.253 and others. CVE-2021-47468 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2021-47468?

CVE-2021-47468 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-2021-47468?

Yes, CVE-2021-47468 has been patched. Fixed versions include 4.4.290, 4.9.288, 4.14.253 and others. If you are running Linux kernel 2.6.32 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2021-47468 actively exploited?

CVE-2021-47468 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-2021-47468

Medium

In the Linux kernel, the following vulnerability has been resolved: isdn: mISDN: Fix sleeping function called from invalid context The driver can call card->isac.release() function from an atomic context. Fix this by calling this function after releasing the lock. The following log reveals it: [ 44.168226 ] BUG: sleeping function called from invalid context at kernel/workqueue.c:3018 [ 44.168941 ] in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 5475, name: modprobe [ 44.169574 ] INFO: lockdep is turned off. [ 44.169899 ] irq event stamp: 0 [ 44.170160 ] hardirqs last enabled at (0): [<0000000000000000>] 0x0 [ 44.170627 ] hardirqs last disabled at (0): [<ffffffff814209ed>] copy_process+0x132d/0x3e00 [ 44.171240 ] softirqs last enabled at (0): [<ffffffff81420a1a>] copy_process+0x135a/0x3e00 [ 44.171852 ] softirqs last disabled at (0): [<0000000000000000>] 0x0 [ 44.172318 ] Preemption disabled at: [ 44.172320 ] [<ffffffffa009b0a9>] nj_release+0x69/0x500 [netjet] [ 44.174441 ] Call Trace: [ 44.174630 ] dump_stack_lvl+0xa8/0xd1 [ 44.174912 ] dump_stack+0x15/0x17 [ 44.175166 ] ___might_sleep+0x3a2/0x510 [ 44.175459 ] ? nj_release+0x69/0x500 [netjet] [ 44.175791 ] __might_sleep+0x82/0xe0 [ 44.176063 ] ? start_flush_work+0x20/0x7b0 [ 44.176375 ] start_flush_work+0x33/0x7b0 [ 44.176672 ] ? trace_irq_enable_rcuidle+0x85/0x170 [ 44.177034 ] ? kasan_quarantine_put+0xaa/0x1f0 [ 44.177372 ] ? kasan_quarantine_put+0xaa/0x1f0 [ 44.177711 ] __flush_work+0x11a/0x1a0 [ 44.177991 ] ? flush_work+0x20/0x20 [ 44.178257 ] ? lock_release+0x13c/0x8f0 [ 44.178550 ] ? __kasan_check_write+0x14/0x20 [ 44.178872 ] ? do_raw_spin_lock+0x148/0x360 [ 44.179187 ] ? read_lock_is_recursive+0x20/0x20 [ 44.179530 ] ? __kasan_check_read+0x11/0x20 [ 44.179846 ] ? do_raw_spin_unlock+0x55/0x900 [ 44.180168 ] ? ____kasan_slab_free+0x116/0x140 [ 44.180505 ] ? _raw_spin_unlock_irqrestore+0x41/0x60 [ 44.180878 ] ? skb_queue_purge+0x1a3/0x1c0 [ 44.181189 ] ? kfree+0x13e/0x290 [ 44.181438 ] flush_work+0x17/0x20 [ 44.181695 ] mISDN_freedchannel+0xe8/0x100 [ 44.182006 ] isac_release+0x210/0x260 [mISDNipac] [ 44.182366 ] nj_release+0xf6/0x500 [netjet] [ 44.182685 ] nj_remove+0x48/0x70 [netjet] [ 44.182989 ] pci_device_remove+0xa9/0x250

Package Linux Kernel

Published 2024-05-22

Last modified 2025-09-24

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-2021-47468 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 2.6.32 and later are affected. Fixed in 4.4.290, 4.9.288, 4.14.253, 4.19.214, 5.4.156, 5.10.76, 5.14.15, 5.15 and their respective stable series.

Affected from

≥ 2.6.32

Fixed in

✓ 4.4.290 4.4.x ✓ 4.9.288 4.9.x ✓ 4.14.253 4.14.x ✓ 4.19.214 4.19.x ✓ 5.4.156 5.4.x ✓ 5.10.76 5.10.x ✓ 5.14.15 5.14.x ✓ 5.15

References

8 total

Kernel Git
https://git.kernel.org/stable/c/37e4f57b22cc5ebb3f80cf0f74fdeb487f082367

Patch
Kernel Git
https://git.kernel.org/stable/c/4054b869dc263228d30a4755800b78f0f2ba0c89

Patch
Kernel Git
https://git.kernel.org/stable/c/6510e80a0b81b5d814e3aea6297ba42f5e76f73c

Patch
Kernel Git
https://git.kernel.org/stable/c/6f95c97e0f9d6eb39c3f2cb45e8fa4268d1b372b

Patch
Kernel Git
https://git.kernel.org/stable/c/9f591cbdbed3d7822b2bdba89b34a6d7b434317d

Patch

Showing 5 of 8 references View all on NVD

Details

CVE ID CVE-2021-47468

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2024-05-22

Modified 2025-09-24

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2021-47468?

CVE-2021-47468 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 2.6.32 onward and has been patched in 4.4.290, 4.9.288, 4.14.253 and others. CVE-2021-47468 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2021-47468?

CVE-2021-47468 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-2021-47468?

Yes. CVE-2021-47468 has been patched. Fixed versions include 4.4.290, 4.9.288, 4.14.253 and others. If you are running Linux kernel 2.6.32 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2021-47468 actively exploited?

No. CVE-2021-47468 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.