Linux Kernel up to 6.8.1 max_entries buffer overflow

CVSS Meta Temp Score
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CTI Interest Score
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6.5$0-$5k0.00

Summaryinfo

A vulnerability, which was classified as critical, was found in Linux Kernel up to 6.8.1. Affected by this issue is some unknown functionality. Such manipulation of the argument max_entries leads to buffer overflow. This vulnerability is traded as CVE-2024-26885. There is no exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.8.1 and classified as critical. Affected by this issue is some unknown functionality. The manipulation of the argument max_entries with an unknown input leads to a buffer overflow vulnerability. Using CWE to declare the problem leads to CWE-120. The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. Impacted is confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix DEVMAP_HASH overflow check on 32-bit arches The devmap code allocates a number hash buckets equal to the next power of two of the max_entries value provided when creating the map. When rounding up to the next power of two, the 32-bit variable storing the number of buckets can overflow, and the code checks for overflow by checking if the truncated 32-bit value is equal to 0. However, on 32-bit arches the rounding up itself can overflow mid-way through, because it ends up doing a left-shift of 32 bits on an unsigned long value. If the size of an unsigned long is four bytes, this is undefined behaviour, so there is no guarantee that we'll end up with a nice and tidy 0-value at the end. Syzbot managed to turn this into a crash on arm32 by creating a DEVMAP_HASH with max_entries > 0x80000000 and then trying to update it. Fix this by moving the overflow check to before the rounding up operation.

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2024-26885 since 02/19/2024. The exploitation is known to be easy. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 11/08/2024).

The vulnerability scanner Nessus provides a plugin with the ID 210006 (Ubuntu 18.04 LTS / 20.04 LTS : Linux kernel vulnerabilities (USN-7088-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.10.214, 5.15.153, 6.1.83, 6.6.23, 6.7.11, 6.8.2 or 6.9-rc1 eliminates this vulnerability. Applying the patch 225da02acdc9/c826502bed93/edf7990baa48/250051acc21f/22079b3a4233/e89386f62ce9/281d464a34f5 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 (210006). 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: 6.6
VulDB Meta Temp Score: 6.5

VulDB Base Score: 5.5
VulDB Temp Score: 5.3
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.8
NVD Vector: 🔍

CVSSv2info

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

Exploitinginfo

Class: Buffer overflow
CWE: CWE-120 / CWE-119
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: 210006
Nessus Name: Ubuntu 18.04 LTS / 20.04 LTS : Linux kernel vulnerabilities (USN-7088-1)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Kernel 5.10.214/5.15.153/6.1.83/6.6.23/6.7.11/6.8.2/6.9-rc1
Patch: 225da02acdc9/c826502bed93/edf7990baa48/250051acc21f/22079b3a4233/e89386f62ce9/281d464a34f5

Timelineinfo

02/19/2024 🔍
04/17/2024 +57 days 🔍
04/17/2024 +0 days 🔍
11/08/2024 +205 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2024-26885 (🔍)
GCVE (CVE): GCVE-0-2024-26885
GCVE (VulDB): GCVE-100-261284

Entryinfo

Created: 04/17/2024 13:23
Updated: 11/08/2024 19:38
Changes: 04/17/2024 13:23 (57), 05/24/2024 08:38 (11), 11/01/2024 12:38 (3), 11/08/2024 19:38 (1)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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