CVE Catalog

CVE-2026-74643

Unknown
Published: Translated: NVD NIST

Summary

A vulnerability in the Linux kernel's DAMON_SAMPLE_MTIER sample module allows a user to trigger a division by zero in damos_quota_score(). This occurs when the node0_mem_free_bp or node0_mem_used_bp parameter is set to zero, leading to a kernel Oops and potential system crash.

Risk Assessment

The risk is a local denial of service via a kernel divide error, which can hang or crash the system. An attacker with access to module parameters can intentionally trigger this issue, causing service unavailability.

Recommendation

Update the Linux kernel to a patched version that adds parameter validation and returns an error for zero values. Until then, avoid setting zero values for node0_mem_free_bp and node0_mem_used_bp in the DAMON_SAMPLE_MTIER module.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: samples/damon/mtier: error out for zero quota goal target values Patch series "mm/damon: avoid division by zero from damos_quota_score()". DAMON_SAMPLE_MTIER and DAMON_LRU_SORT allow the user to trigger division by zero in damos_quota_score(). Avoid it by adding parameters validation checks. This patch (of 2): damos_quota_score() can trigger division by zero if the target_value is zero. DAMON_SAMPLE_MTIER lets users set the target_value via node0_mem_{used,free}_bp parameters. It doesn't guard zero value case, though. As a result, users can trigger division by zero. Fix the issue by returning an error when the user tries to start DAMON with zero node0_mem_{used,free}_bp parameter values. DAMON_SAMPLE_MTIER is just a sample module, but the consequence is quite bad. Also the zero node0_mem_free_bp parameter might look like a reasonable setup to some users. Hence, the issue might really happen in the real world. One reliable way to reproduce the issue is like below: # cd /sys/module/damon_sample_mtier/parameters # echo 4096 > node0_start_addr # echo 8192 > node0_end_addr # echo 8192 > node1_start_addr # echo 81920 > node1_end_addr # echo 0 > node0_mem_free_bp # echo Y > enabled # dmesg -w [...] [18792.235916] Oops: divide error: 0000 [#1] SMP NOPTI [...] [18792.242787] RIP: 0010:damos_quota_score+0x6f/0x480 [...] This issue was discovered [1] by Sashiko.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS