CVE-2024-42102
MediumIn 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.
CVSS 3.1 score
4.7
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness type
CWE-369CVE-2024-42102 is a Divide By Zero vulnerability
What is Divide By Zero?
The product divides a value by zero, causing a crash or unexpected behaviour. Learn more on MITRE CWE
References
The following references provide additional information about CVE-2024-42102 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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PatchKernel patch commithttps://git.kernel.org/stable/c/000099d71648504fb9c7a4616f92c2b70c3e44ec
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PatchKernel patch commithttps://git.kernel.org/stable/c/145faa3d03688cbb7bbaaecbd84c01539852942c
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PatchKernel patch commithttps://git.kernel.org/stable/c/23a28f5f3f6ca1e4184bd0e9631cd0944cf1c807
Frequently asked questions
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What is CVE-2024-42102?
CVE-2024-42102 is a Medium severity Linux kernel vulnerability with a CVSS score of 4.7 out of 10 , classified as a Divide By Zero flaw (CWE-369) . CVE-2024-42102 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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What is the CVSS score for CVE-2024-42102?
CVE-2024-42102 has a CVSS score of 4.7 out of 10, rated Medium severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H. -
Is there a patch available for CVE-2024-42102?
No patch is currently available for CVE-2024-42102. Monitor the NIST NVD and your Linux distribution's security advisories for updates.
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Is CVE-2024-42102 actively exploited?
No — CVE-2024-42102 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
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What is Divide By Zero (CWE-369)?
The product divides a value by zero, causing a crash or unexpected behaviour. View CWE-369 on MITRE CWE →