# CVE-2026-89457: linux: In the Linux kernel, the following vulnerability has been resolved:  s390/dasd: Guard sysfs discipline callbacks agai...

CVE-2026-89457 is fixed in 2 products on 1 platform, first by DEBIAN-CVE-2026-89457, released September 23, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-89457
- Priority: Routine
- CVSS: n/a
- EPSS: 0.0018
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 11, 2026

## Description

In the Linux kernel, the following vulnerability has been resolved:  s390/dasd: Guard sysfs discipline callbacks against unallocated private data  Several sysfs show/store handlers call a discipline callback that dereferences device->private, either directly or through the DASD_DEFINE_ATTR() macro. During dasd_generic_set_online() the discipline is assigned before check_device() allocates device->private, so an unprivileged read of one of these world-readable attributes in that window dereferences a NULL pointer and panics.  Guard the dereference inside each callback that actually touches device->private.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 12.15 (bookworm) | 6.1.190-1 | [DEBIAN-CVE-2026-89457](https://patchblox.com/security/data/fix/linux/debian-cve-2026-89457.md) | Sep 23, 2026 |
| Linux | linux Debian 13.5 (trixie) | 6.12.111-1 | [DEBIAN-CVE-2026-89457](https://patchblox.com/security/data/fix/linux/debian-cve-2026-89457.md) | Sep 23, 2026 |
| Linux | linux Debian 14 | 7.2.6-1 | [DEBIAN-CVE-2026-89457](https://patchblox.com/security/data/fix/linux/debian-cve-2026-89457.md) | Sep 23, 2026 |
| Linux | linux-6.12 Debian 12.15 (bookworm) | 6.12.111-1~deb12u1 | [DEBIAN-CVE-2026-89457](https://patchblox.com/security/data/fix/linux/debian-cve-2026-89457.md) | Sep 23, 2026 |

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Data as of 2026-11-08T13:06:02Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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