Deadlock in Linux kernel - CVE-2026-46063
Published: May 28, 2026
Vulnerability identifier: #VU132427
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-46063
CWE-ID: CWE-833
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to improper locking in shadow stack signal frame handling during sigreturn when reading the shadow stack signal frame from userspace. A local user can trigger a page fault during sigreturn to cause a denial of service.
The issue can occur when a writer on another CPU is waiting on the mmap lock, leading to a deadlock in the fault handling path.
How to mitigate CVE-2026-46063
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/3d29db827502067626062f5c74dd502d14ab15bc
- https://git.kernel.org/stable/c/4f3374c990fb2adec06d20fd6d780927811c9aa0
- https://git.kernel.org/stable/c/9874b2917b9fbc30956fee209d3c4aa47201c64e
- https://git.kernel.org/stable/c/d042d69b417515959e49021fef008c9b04a99bd5
- https://git.kernel.org/stable/c/e2c2b044458cbf22da05264fa707308e8d4f86f9