What is CVE-2021-47340?

CVE-2021-47340 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, classified as a NULL Pointer Dereference flaw (CWE-476), affecting Linux kernel versions from 2.6.36 onward and patched in 4.4.276, 4.9.276, 4.14.240 and others. CVE-2021-47340 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2021-47340?

CVE-2021-47340 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-2021-47340?

Yes, CVE-2021-47340 has been patched. Fixed versions include 4.4.276, 4.9.276, 4.14.240 and others. If you are running Linux kernel 2.6.36 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2021-47340 actively exploited?

CVE-2021-47340 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is NULL Pointer Dereference (CWE-476)?

The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. See MITRE CWE for full details: https://cwe.mitre.org/data/definitions/476.html

CVE-2021-47340

Medium

In the Linux kernel, the following vulnerability has been resolved: jfs: fix GPF in diFree Avoid passing inode with JFS_SBI(inode->i_sb)->ipimap == NULL to diFree()[1]. GFP will appear: struct inode *ipimap = JFS_SBI(ip->i_sb)->ipimap; struct inomap *imap = JFS_IP(ipimap)->i_imap; JFS_IP() will return invalid pointer when ipimap == NULL Call Trace: diFree+0x13d/0x2dc0 fs/jfs/jfs_imap.c:853 [1] jfs_evict_inode+0x2c9/0x370 fs/jfs/inode.c:154 evict+0x2ed/0x750 fs/inode.c:578 iput_final fs/inode.c:1654 [inline] iput.part.0+0x3fe/0x820 fs/inode.c:1680 iput+0x58/0x70 fs/inode.c:1670

Package Linux Kernel

Published 2024-05-21

Last modified 2025-12-10

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-476

CVE-2021-47340 is a NULL Pointer Dereference vulnerability

What is NULL Pointer Dereference?

The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. Learn more on MITRE CWE

Affected versions

Linux kernel versions 2.6.36 and later are affected. Fixed in 4.4.276, 4.9.276, 4.14.240, 4.19.198, 5.4.133, 5.10.51, 5.12.18, 5.13.3, 5.14 and their respective stable series.

Affected from

≥ 2.6.36

Fixed in

✓ 4.4.276 4.4.x ✓ 4.9.276 4.9.x ✓ 4.14.240 4.14.x ✓ 4.19.198 4.19.x ✓ 5.4.133 5.4.x ✓ 5.10.51 5.10.x ✓ 5.12.18 5.12.x ✓ 5.13.3 5.13.x ✓ 5.14

References

9 total

Kernel Git
https://git.kernel.org/stable/c/3bb27e27240289b47d3466f647a55c567adbdc3a

Patch
Kernel Git
https://git.kernel.org/stable/c/42f102ea1943ecb10a0756bf75424de5d1d5beed

Patch
Kernel Git
https://git.kernel.org/stable/c/49def1b0644892e3b113673c13d650c3060b43bc

Patch
Kernel Git
https://git.kernel.org/stable/c/745c9a59422c63f661f4374ed5181740db4130a1

Patch
Kernel Git
https://git.kernel.org/stable/c/7bde24bde490f3139eee147efc6d60d6040fe975

Patch

Showing 5 of 9 references View all on NVD

Details

CVE ID CVE-2021-47340

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2024-05-21

Modified 2025-12-10

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2021-47340?

CVE-2021-47340 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as a NULL Pointer Dereference flaw (CWE-476) . It affects Linux kernel versions from 2.6.36 onward and has been patched in 4.4.276, 4.9.276, 4.14.240 and others. CVE-2021-47340 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2021-47340?

CVE-2021-47340 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-2021-47340?

Yes. CVE-2021-47340 has been patched. Fixed versions include 4.4.276, 4.9.276, 4.14.240 and others. If you are running Linux kernel 2.6.36 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2021-47340 actively exploited?

No. CVE-2021-47340 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.