Deadlock in Linux kernel - CVE-2026-98478

Vulnerability identifier: #VU156778

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-2026-98478

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 by deadlocking UFS error recovery.

The vulnerability exists due to an unrecoverable circular wait in the Linux kernel UFS core when handling error recovery. The ufshcd_err_handling_prepare() function quiesces the shared host tagset, including the pseudo SCSI device request queue, preventing internal commands subsequently issued by ufshcd_verify_dev_init() from being dispatched. A local user can trigger this deadlock, if able to induce the relevant error-recovery conditions, to prevent recovery and cause a denial of service.

Linux kernel
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)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
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

• https://git.kernel.org/stable/c/9f6f4840def931814c106fc800f57a2d26befee6
• https://git.kernel.org/stable/c/b52d695d062095327b944acf7daabbc816ab319b

• Deadlock in Linux kernel ufs core driver
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more