# CVE-2026-23235: f2fs: fix out-of-bounds access in sysfs attribute read/write

CVE-2026-23235 is fixed in 36 products on 1 platform, first by DEBIAN-CVE-2026-23235, released March 4, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-23235
- Priority: High
- CVSS: 7.8 (Important)
- EPSS: 0.0018
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Mar 4, 2026
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-23235

## Description

In the Linux kernel, the following vulnerability has been resolved:  f2fs: fix out-of-bounds access in sysfs attribute read/write  Some f2fs sysfs attributes suffer from out-of-bounds memory access and incorrect handling of integer values whose size is not 4 bytes.  For example: vm:~# echo 65537 > /sys/fs/f2fs/vde/carve_out vm:~# cat /sys/fs/f2fs/vde/carve_out 65537 vm:~# echo 4294967297 > /sys/fs/f2fs/vde/atgc_age_threshold vm:~# cat /sys/fs/f2fs/vde/atgc_age_threshold 1  carve_out maps to {struct f2fs_sb_info}->carve_out, which is a 8-bit integer. However, the sysfs interface allows setting it to a value larger than 255, resulting in an out-of-range update.  atgc_age_threshold maps to {struct atgc_management}->age_threshold, which is a 64-bit integer, but its sysfs interface cannot correctly set values larger than UINT_MAX.  The root causes are: 1. __sbi_store() treats all default values as unsigned int, which prevents updating integers larger than 4 bytes and causes out-of-bounds writes for integers smaller than 4 bytes.  2. f2fs_sbi_show() also assumes all default values are unsigned int, leading to out-of-bounds reads and incorrect access to integers larger than 4 bytes.  This patch introduces {struct f2fs_attr}->size to record the actual size of the integer associated with each sysfs attribute. With this information, sysfs read and write operations can correctly access and update values according to their real data size, avoiding memory corruption and truncation.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | kernel-uek ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-core ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-core ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-core ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-core ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-devel ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-devel ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-modules ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-modules ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-modules-core ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-modules-core ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-modules-deprecated ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-modules-deprecated ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-modules-desktop ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-modules-desktop ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-modules-extra ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-modules-extra ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-modules-extra-netfilter ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-modules-extra-netfilter ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-modules-usb ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-modules-usb ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-modules-wireless ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-debug-modules-wireless ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-devel ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-devel ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-doc ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-doc ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-modules ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-modules ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-modules-core ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-modules-core ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-modules-deprecated ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-modules-deprecated ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-modules-desktop ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-modules-desktop ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-modules-extra ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-modules-extra ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-modules-extra-netfilter ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-modules-extra-netfilter ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-modules-usb ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-modules-usb ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-modules-wireless ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-modules-wireless ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-tools ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek-tools ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-core ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-core ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-devel ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-devel ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-modules ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-modules ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-modules-core ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-modules-core ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-modules-deprecated ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-modules-deprecated ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-modules-desktop ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-modules-desktop ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-modules-extra ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-modules-extra ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-modules-extra-netfilter ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-modules-extra-netfilter ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-modules-usb ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-modules-usb ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-modules-wireless ol 10 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | kernel-uek64k-modules-wireless ol 9 | 0:6.12.0-200.74.27.el9uek | [ELSA-2026-50160](https://patchblox.com/security/data/fix/linux/elsa-2026-50160.md) | Mar 20, 2026 |
| Linux | linux Debian 12.15 (bookworm) | 6.1.164-1 | [DEBIAN-CVE-2026-23235](https://patchblox.com/security/data/fix/linux/debian-cve-2026-23235.md) | Mar 4, 2026 |
| Linux | linux Debian 13.5 (trixie) | 6.12.74-2 | [DEBIAN-CVE-2026-23235](https://patchblox.com/security/data/fix/linux/debian-cve-2026-23235.md) | Mar 4, 2026 |
| Linux | linux Debian 14 | 6.18.13-1 | [DEBIAN-CVE-2026-23235](https://patchblox.com/security/data/fix/linux/debian-cve-2026-23235.md) | Mar 4, 2026 |

---

Data as of 2026-11-09T01:18:40Z 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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