CVE-2026-43209
Analyzed Analyzed - Analysis Complete
Linux Kernel Minix Filesystem Sanity Check Bypass

Publication date: 2026-05-06

Last updated on: 2026-05-11

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: minix: Add required sanity checking to minix_check_superblock() The fs/minix implementation of the minix filesystem does not currently support any other value for s_log_zone_size than 0. This is also the only value supported in util-linux; see mkfs.minix.c line 511. In addition, this patch adds some sanity checking for the other minix superblock fields, and moves the minix_blocks_needed() checks for the zmap and imap also to minix_check_super_block(). This also closes a related syzbot bug report.
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Meta Information
Published
2026-05-06
Last Modified
2026-05-11
Generated
2026-06-16
AI Q&A
2026-05-06
EPSS Evaluated
2026-06-15
NVD
CVE-2026-43209
EUVD
EUVD-2026-27770
Affected Vendors & Products
Showing 13 associated CPEs
Vendor Product Version / Range
linux linux_kernel 2.6.12
linux linux_kernel 2.6.12
linux linux_kernel 2.6.12
linux linux_kernel 2.6.12
linux linux_kernel 2.6.12
linux linux_kernel 2.6.12
linux linux_kernel From 6.2 (inc) to 6.6.128 (exc)
linux linux_kernel From 6.7 (inc) to 6.12.75 (exc)
linux linux_kernel From 6.13 (inc) to 6.18.16 (exc)
linux linux_kernel From 6.19 (inc) to 6.19.6 (exc)
linux linux_kernel From 5.11 (inc) to 5.15.202 (exc)
linux linux_kernel From 5.16 (inc) to 6.1.165 (exc)
linux linux_kernel From 2.6.12.1 (inc) to 5.10.252 (exc)
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Exploitability
CWE
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CWE ID Description
CWE-UNKNOWN
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Executive Summary

This vulnerability is related to the Linux kernel's implementation of the Minix filesystem. Specifically, the function minix_check_superblock() lacked necessary sanity checks for certain fields in the Minix superblock. The filesystem only supports a value of 0 for the s_log_zone_size field, but previously there was no validation enforcing this. The patch adds required sanity checking to ensure that unsupported or unexpected values are not accepted, which helps prevent potential issues caused by malformed or malicious superblock data.

Impact Analysis

Without proper sanity checks in the Minix filesystem superblock, there is a risk that malformed or malicious filesystem metadata could cause unexpected behavior in the Linux kernel. This could potentially lead to system instability, crashes, or other unintended effects when accessing or mounting Minix filesystems. By adding these checks, the vulnerability reduces the risk of such issues.

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