Deadlock in Linux kernel - CVE-2026-98939
Published: October 23, 2026
Vulnerability identifier: #VU157576
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-2026-98939
CWE-ID: CWE-833
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to potentially cause a denial of service through a kernel deadlock.
The vulnerability exists due to a circular locking dependency in pud_free_pmd_page() in the x86 memory-management subsystem when a GFP_KERNEL allocation can enter memory reclaim while the init_mm mmap lock is held during huge PUD mapping setup. A local user can exercise the affected mapping and memory-reclaim paths to potentially cause a deadlock involving the mmap lock, memory reclaim, and the TTM page-pool lock, resulting in a denial of service.
Affected software
Linux kernel
How to mitigate CVE-2026-98939
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3