Oracle Linux: CVE-2024-42102: ELSA-2024-6567: kernel security update (MODERATE) (Multiple Advisories)

Oracle Linux: CVE-2024-42102: ELSA-2024-6567:kernel security update (MODERATE) (Multiple Advisories)

Severity

4

CVSS

(AV:L/AC:H/Au:S/C:N/I:N/A:C)

Published

07/30/2024

Created

11/12/2024

Added

10/16/2024

Modified

01/07/2025

Description

In the Linux kernel, the following vulnerability has been resolved: Revert "mm/writeback: fix possible divide-by-zero in wb_dirty_limits(), again" Patch series "mm: Avoid possible overflows in dirty throttling". Dirty throttling logic assumes dirty limits in page units fit into 32-bits.This patch series makes sure this is true (see patch 2/2 for more details). This patch (of 2): This reverts commit 9319b647902cbd5cc884ac08a8a6d54ce111fc78. The commit is broken in several ways.Firstly, the removed (u64) cast from the multiplication will introduce a multiplication overflow on 32-bit archs if wb_thresh * bg_thresh >= 1<<32 (which is actually common - the default settings with 4GB of RAM will trigger this).Secondly, the div64_u64() is unnecessarily expensive on 32-bit archs.We have div64_ul() in case we want to be safe & cheap.Thirdly, if dirty thresholds are larger than 1<<32 pages, then dirty balancing is going to blow up in many other spectacular ways anyway so trying to fix one possible overflow is just moot. A vulnerability was found in the wb_dirty_limits() function in the Linux kernel, where a removed (u64) cast in the dtc->wb_thresh * dtc->bg_thresh operation can result in multiplication overflow on 32-bit architectures. This issue could lead to memory corruption or performance issues.

Solution(s)

• oracle-linux-upgrade-kernel

References

• https://attackerkb.com/topics/cve-2024-42102
• CVE - 2024-42102
• ELSA-2024-6567