# CVE-2026-74643: linux: In the Linux kernel, the following vulnerability has been resolved:  samples/damon/mtier: error out for zero quota go...

CVE-2026-74643 is fixed in linux on 1 platform by DEBIAN-CVE-2026-74643 (version 7.1.9-1), released September 4, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-74643
- Priority: Routine
- CVSS: n/a
- EPSS: 0.0017
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Aug 22, 2026

## Description

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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 14 | 7.1.9-1 | [DEBIAN-CVE-2026-74643](https://patchblox.com/security/data/fix/linux/debian-cve-2026-74643.md) | Sep 4, 2026 |

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Data as of 2026-11-08T00:53:09Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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