Deadlock in Linux kernel - CVE-2026-90209

Vulnerability identifier: #VU151267

CSH Severity: Low

CVSS v4: 5.7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-90209

CWE-ID: CWE-833

Exploitation vector: Local access

Exploit availability: No public exploit available

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

The vulnerability exists due to improper locking in the s390 debug subsystem's debug area unregistration handling when a debugfs file associated with a debug area is written concurrently with debug area unregistration. A local user can write to an associated debugfs file while debug area unregistration occurs to cause a denial of service.

Linux kernel
Debian Linux
Ubuntu
linux-nvidia-tegra-igx (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-nvidia-tegra-5.15 (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux (Ubuntu package)
linux-oracle (Ubuntu package)
linux-gcp (Ubuntu package)
linux-aws (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-nvidia-tegra-igx (Ubuntu package) - update to 5.15.0-1059.59
linux-nvidia-tegra (Ubuntu package) - update to 5.15.0-1070.72
linux-nvidia-tegra-5.15 (Ubuntu package) - update to 5.15.0-1070.72~20.04.1
linux-azure-fde (Ubuntu package) - update to 5.15.0-1124.133
linux (Ubuntu package) - update to 7.0.0-42.42
linux-oracle (Ubuntu package) - update to 7.0.0-1015.16
linux-gcp (Ubuntu package) - update to 7.0.0-1016.18
linux-aws (Ubuntu package) - update to 7.0.0-1016.17
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/183f8f6d64bb0510070c856b9927618c53014a7b
• https://git.kernel.org/stable/c/445c31ac638fd1af203d79bdf25fc0cb3149fbbc
• https://git.kernel.org/stable/c/45bb341d1b73eb293e0dd43d9b72bbc8b615d0ba
• https://git.kernel.org/stable/c/54e1259b75d6402a1d0cfb822b9bb2c507e53dab
• https://git.kernel.org/stable/c/5d83f3faa3fb7f23f298cfd40382611999de5d1d
• https://git.kernel.org/stable/c/a08b70ed2d1ec907353a72f15163b8e34ff4b2f8
• https://git.kernel.org/stable/c/a214c3dacc779b2afcb0ac9c8001e45ee4ffb2ed

• Deadlock in Linux kernel s390 kernel
• Debian update for linux
• Ubuntu update for linux-azure-fde
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more
• Ubuntu update for linux-nvidia-tegra, linux-nvidia-tegra-5.15, linux-nvidia-tegra-igx
• Ubuntu update for linux, linux-aws, linux-aws-5.15 and more