4.7

CVE-2024-42102

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.
Data is provided by the National Vulnerability Database (NVD)
Linux ≫ Linux Kernel Version >= 4.19.307 < 4.19.318
Linux ≫ Linux Kernel Version >= 5.4.269 < 5.4.280
Linux ≫ Linux Kernel Version >= 5.10.210 < 5.10.222
Linux ≫ Linux Kernel Version >= 5.15.149 < 5.15.163
Linux ≫ Linux Kernel Version >= 6.1.79 < 6.1.98
Linux ≫ Linux Kernel Version >= 6.6.18 < 6.6.39
Linux ≫ Linux Kernel Version >= 6.8 < 6.9.9
Zu dieser CVE wurde keine CISA KEV oder CERT.AT-Warnung gefunden.
EPSS Metriken
Type Source Score Percentile
EPSS FIRST.org 0.01% 0.009
CVSS Metriken
Source Base Score Exploit Score Impact Score Vector string
nvd@nist.gov 4.7 1 3.6
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE-369 Divide By Zero

The product divides a value by zero.