5.5
MEDIUM
CVE-2024-50263
Linux Kernel fork: KSM and Khugepaged Hook Invalidation
Description

In the Linux kernel, the following vulnerability has been resolved: fork: only invoke khugepaged, ksm hooks if no error There is no reason to invoke these hooks early against an mm that is in an incomplete state. The change in commit d24062914837 ("fork: use __mt_dup() to duplicate maple tree in dup_mmap()") makes this more pertinent as we may be in a state where entries in the maple tree are not yet consistent. Their placement early in dup_mmap() only appears to have been meaningful for early error checking, and since functionally it'd require a very small allocation to fail (in practice 'too small to fail') that'd only occur in the most dire circumstances, meaning the fork would fail or be OOM'd in any case. Since both khugepaged and KSM tracking are there to provide optimisations to memory performance rather than critical functionality, it doesn't really matter all that much if, under such dire memory pressure, we fail to register an mm with these. As a result, we follow the example of commit d2081b2bf819 ("mm: khugepaged: make khugepaged_enter() void function") and make ksm_fork() a void function also. We only expose the mm to these functions once we are done with them and only if no error occurred in the fork operation.

INFO

Published Date :

Nov. 11, 2024, 2:15 p.m.

Last Modified :

Dec. 9, 2024, 10:15 p.m.

Source :

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Remotely Exploitable :

No

Impact Score :

3.6

Exploitability Score :

1.8
Affected Products

The following products are affected by CVE-2024-50263 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Linux linux_kernel
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2024-50263.

URL Resource
https://git.kernel.org/stable/c/3b85aa0da8cd01173b9afd1f70080fbb9576c4b0 Patch
https://git.kernel.org/stable/c/985da552a98e27096444508ce5d853244019111f Patch
https://project-zero.issues.chromium.org/issues/373391951

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2024-50263 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2024-50263 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Dec. 09, 2024

    Action Type Old Value New Value
    Added Reference https://project-zero.issues.chromium.org/issues/373391951
  • Initial Analysis by nvd@nist.gov

    Nov. 14, 2024

    Action Type Old Value New Value
    Added CVSS V3.1 NIST AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
    Changed Reference Type https://git.kernel.org/stable/c/3b85aa0da8cd01173b9afd1f70080fbb9576c4b0 No Types Assigned https://git.kernel.org/stable/c/3b85aa0da8cd01173b9afd1f70080fbb9576c4b0 Patch
    Changed Reference Type https://git.kernel.org/stable/c/985da552a98e27096444508ce5d853244019111f No Types Assigned https://git.kernel.org/stable/c/985da552a98e27096444508ce5d853244019111f Patch
    Added CWE NIST NVD-CWE-noinfo
    Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.8 up to (excluding) 6.11.7 *cpe:2.3:o:linux:linux_kernel:6.12:rc1:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.12:rc2:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.12:rc3:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.12:rc4:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.12:rc5:*:*:*:*:*:*
  • CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Nov. 11, 2024

    Action Type Old Value New Value
    Added Description In the Linux kernel, the following vulnerability has been resolved: fork: only invoke khugepaged, ksm hooks if no error There is no reason to invoke these hooks early against an mm that is in an incomplete state. The change in commit d24062914837 ("fork: use __mt_dup() to duplicate maple tree in dup_mmap()") makes this more pertinent as we may be in a state where entries in the maple tree are not yet consistent. Their placement early in dup_mmap() only appears to have been meaningful for early error checking, and since functionally it'd require a very small allocation to fail (in practice 'too small to fail') that'd only occur in the most dire circumstances, meaning the fork would fail or be OOM'd in any case. Since both khugepaged and KSM tracking are there to provide optimisations to memory performance rather than critical functionality, it doesn't really matter all that much if, under such dire memory pressure, we fail to register an mm with these. As a result, we follow the example of commit d2081b2bf819 ("mm: khugepaged: make khugepaged_enter() void function") and make ksm_fork() a void function also. We only expose the mm to these functions once we are done with them and only if no error occurred in the fork operation.
    Added Reference kernel.org https://git.kernel.org/stable/c/3b85aa0da8cd01173b9afd1f70080fbb9576c4b0 [No types assigned]
    Added Reference kernel.org https://git.kernel.org/stable/c/985da552a98e27096444508ce5d853244019111f [No types assigned]
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2024-50263 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2024-50263 weaknesses.

CVSS31 - Vulnerability Scoring System
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