Linux Kernel up to 5.13.2 jfs diFree null pointer dereference

CVSS Meta Temp Score
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CTI Interest Score
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4.9$0-$5k0.00

Summaryinfo

A vulnerability described as problematic has been identified in Linux Kernel up to 5.13.2. This issue affects the function diFree of the component jfs. Such manipulation leads to an unknown weakness. This vulnerability is documented as CVE-2021-47340. There is not any exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Linux Kernel up to 5.13.2 and classified as problematic. Affected by this issue is the function diFree of the component jfs. Using CWE to declare the problem leads to CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. The impact remains unknown. CVE summarizes:

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

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2021-47340 since 05/21/2024. The exploitation is known to be difficult. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 249849 (Linux Distros Unpatched Vulnerability : CVE-2021-47340), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 4.4.276, 4.9.276, 4.14.240, 4.19.198, 5.4.133, 5.10.51, 5.12.18 or 5.13.3 eliminates this vulnerability. Applying the patch 7bde24bde490/745c9a59422c/49def1b06448/aff8d95b6905/a21e5cb1a64c/801893695036/3bb27e272402/42f102ea1943/9d574f985fe3 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (249849). Once again VulDB remains the best source for vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.0
VulDB Meta Temp Score: 4.9

VulDB Base Score: 4.6
VulDB Temp Score: 4.4
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔍

CVSSv2info

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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 249849
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2021-47340

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Kernel 4.4.276/4.9.276/4.14.240/4.19.198/5.4.133/5.10.51/5.12.18/5.13.3
Patch: 7bde24bde490/745c9a59422c/49def1b06448/aff8d95b6905/a21e5cb1a64c/801893695036/3bb27e272402/42f102ea1943/9d574f985fe3

Timelineinfo

05/21/2024 🔍
05/21/2024 +0 days 🔍
05/21/2024 +0 days 🔍
08/18/2025 +454 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2021-47340 (🔍)
GCVE (CVE): GCVE-0-2021-47340
GCVE (VulDB): GCVE-100-265676

Entryinfo

Created: 05/21/2024 20:09
Updated: 08/18/2025 09:47
Changes: 05/21/2024 20:09 (56), 05/13/2025 09:27 (14), 08/18/2025 09:47 (2)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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