SB20260918278 - Race condition in Linux kernel md driver

Description

This security bulletin contains information about 1 vulnerability.

1) Race condition (CVE-ID: CVE-2026-90400)

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSSv4: 5.6 [CVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a local privileged user to cause a denial of service.

The vulnerability exists due to a race condition in the md_start_sync() RAID synchronization path when spare configuration changes occur concurrently with normal I/O. A local privileged user can cause spare configuration changes to race with normal I/O to cause a denial of service.

The race can cause rdev_dec_pending() to be called with a NULL pointer.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/81b39df5d701976cf20e52f33106c1fc1603b4cb
• https://git.kernel.org/stable/c/c3777d16bc3335c0ac4bdad0551c80d38c5d94cc
• https://git.kernel.org/stable/c/c7d34d17ea43ebc86b45d439ebb435e11ca44bca
• https://git.kernel.org/stable/c/e5ac7ab78467b064f1da8b0f3042a63595fafcfd