Race condition in Linux kernel - CVE-2026-90400

Vulnerability identifier: #VU151080

CSH Severity: Low

CVSS v4: 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]

CVE-ID: CVE-2026-90400

CWE-ID: CWE-362

Exploitation vector: Local access

Exploit availability: No public exploit available

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.

Linux kernel
Debian Linux
Ubuntu
linux (Ubuntu package)
linux-aws (Ubuntu package)
linux-gcp (Ubuntu package)
linux-oracle (Ubuntu package)
linux-ibm (Ubuntu package)
linux-hwe-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux (Debian package)

Install security update from vendor's repository.

linux (Ubuntu package) - update to 7.0.0-42.42
linux-aws (Ubuntu package) - update to 7.0.0-1016.17
linux-gcp (Ubuntu package) - update to 7.0.0-1016.18
linux-oracle (Ubuntu package) - update to 7.0.0-1015.16
linux-ibm (Ubuntu package) - update to 7.0.0-1017.17
linux-hwe-7.0 (Ubuntu package) - update to 7.0.0-42.42~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1017.17
linux (Debian package) - update to 6.12.111-1

• 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

• Race condition in Linux kernel md driver
• Debian update for linux
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more