NULL pointer dereference in Linux kernel - CVE-2026-31477

 

NULL pointer dereference in Linux kernel - CVE-2026-31477

Published: April 24, 2026


Vulnerability identifier: #VU127671
CSH Severity: Low
CVSS v4: 6.8 [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]
CVE-ID: CVE-2026-31477
CWE-ID: CWE-476
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

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

The vulnerability exists due to a NULL pointer dereference in smb2_lock() when processing SMB lock rollback operations after allocation failure. A local user can trigger allocation failure during lock rollback to cause a denial of service.


Affected software

Linux kernel
Debian Linux
openEuler
Ubuntu
python3-perf-debuginfo
kernel
bpftool
bpftool-debuginfo
kernel-debuginfo
kernel-debugsource
kernel-devel
kernel-headers
kernel-source
kernel-tools
kernel-tools-debuginfo
kernel-tools-devel
perf
perf-debuginfo
python3-perf
linux (Debian package)
linux (Ubuntu package)
linux-fips (Ubuntu package)
linux-hwe-6.8 (Ubuntu package)
linux-ibm (Ubuntu package)
linux-oracle-6.8 (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-aws-6.8 (Ubuntu package)
linux-aws (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux-azure-fde-6.8 (Ubuntu package)
linux-azure (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-gcp-fips (Ubuntu package)

How to mitigate CVE-2026-31477

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
python3-perf-debuginfo - update to 5.10.0-315.0.0.218
kernel - update to 5.10.0-315.0.0.218
bpftool - update to 5.10.0-315.0.0.218
bpftool-debuginfo - update to 5.10.0-315.0.0.218
kernel-debuginfo - update to 5.10.0-315.0.0.218
kernel-debugsource - update to 5.10.0-315.0.0.218
kernel-devel - update to 5.10.0-315.0.0.218
kernel-headers - update to 5.10.0-315.0.0.218
kernel-source - update to 5.10.0-315.0.0.218
kernel-tools - update to 5.10.0-315.0.0.218
kernel-tools-debuginfo - update to 5.10.0-315.0.0.218
kernel-tools-devel - update to 5.10.0-315.0.0.218
perf - update to 5.10.0-315.0.0.218
perf-debuginfo - update to 5.10.0-315.0.0.218
python3-perf - update to 5.10.0-315.0.0.218
linux (Debian package) - addressed in versions 6.1.170-1, 6.12.85-1
linux (Ubuntu package) - addressed in versions 6.8.0-136.136, 6.8.0-1046.50, 6.8.0-1059.67, 6.8.0-1064.72, 6.8.0-1064.72~22.04.1, 6.8.1-1056.57, 6.8.1-1056.57~22.04.2
linux-fips (Ubuntu package) - addressed in versions 6.8.0-136.136+fips2, 6.8.0-136.136.2, 6.8.0-136.136.2~22.04.1, 6.8.0-1058.61
linux-hwe-6.8 (Ubuntu package) - update to 6.8.0-136.136~22.04.1
linux-ibm (Ubuntu package) - addressed in versions 6.8.0-1030.31, 6.8.0-1033.34, 6.8.0-1061.62, 6.8.0-1061.62~22.04.1
linux-oracle-6.8 (Ubuntu package) - update to 6.8.0-1058.61~22.04.1
linux-nvidia (Ubuntu package) - addressed in versions 6.8.0-1059.62, 6.8.0-1059.62.1, 6.8.0-1059.62~22.04.1
linux-aws-6.8 (Ubuntu package) - addressed in versions 6.8.0-1061.64+fips1, 6.8.0-1061.64~22.04.1
linux-aws (Ubuntu package) - update to 6.8.0-1061.64+1
linux-azure-fde (Ubuntu package) - update to 6.8.0-1062.69
linux-azure-fde-6.8 (Ubuntu package) - update to 6.8.0-1062.69~22.04.1
linux-azure (Ubuntu package) - addressed in versions 6.8.0-1063.71, 6.8.0-1063.71~22.04.1
linux-azure-fips (Ubuntu package) - update to 6.8.0-1063.71+fips2
linux-gcp-fips (Ubuntu package) - update to 6.8.0-1064.72+fips1

External References

Related Security Bulletins