NULL pointer dereference in Linux kernel - CVE-2025-38562
Published: August 20, 2025 / Updated: September 25, 2025
Vulnerability identifier: #VU114271
CSH Severity: Medium
CVSS v4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2025-38562
CWE-ID: CWE-476
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to perform a denial of service (DoS) attack.
The vulnerability exists due to NULL pointer dereference within the krb5_authenticate() function in fs/smb/server/smb2pdu.c. A remote user can perform a denial of service (DoS) attack.
Affected software
Linux kernel
Ubuntu
Anolis OS
linux (Ubuntu package)
linux-aws (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-nvidia-tegra-5.15 (Ubuntu package)
linux-intel-iot-realtime (Ubuntu package)
linux-ibm-5.15 (Ubuntu package)
linux-intel-iotg (Ubuntu package)
linux-azure (Ubuntu package)
linux-azure-5.15 (Ubuntu package)
linux-gcp-5.15 (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-azure-fde (Ubuntu package)
kernel-tools
kernel-64k-devel
kernel-64k-debug-devel
kernel-64k-debug
kernel-64k
python3-perf
perf
kernel-tools-libs-devel
kernel-tools-libs
kernel-headers
kernel-devel
kernel-debug-devel
kernel-debug
kernel
bpftool
linux-aws-fips (Ubuntu package)
linux-lowlatency (Ubuntu package)
linux-hwe-6.8 (Ubuntu package)
linux-xilinx (Ubuntu package)
linux-gcp (Ubuntu package)
linux-ibm (Ubuntu package)
linux-nvidia-lowlatency (Ubuntu package)
linux-gcp-fips (Ubuntu package)
linux-gcp-6.8 (Ubuntu package)
linux-azure-6.8 (Ubuntu package)
linux-raspi-realtime (Ubuntu package)
linux-realtime-6.8 (Ubuntu package)
linux-oem-6.14 (Ubuntu package)
linux-realtime-6.14 (Ubuntu package)
linux-aws-6.14 (Ubuntu package)
linux-gcp-6.14 (Ubuntu package)
Ubuntu
Anolis OS
linux (Ubuntu package)
linux-aws (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-nvidia-tegra-5.15 (Ubuntu package)
linux-intel-iot-realtime (Ubuntu package)
linux-ibm-5.15 (Ubuntu package)
linux-intel-iotg (Ubuntu package)
linux-azure (Ubuntu package)
linux-azure-5.15 (Ubuntu package)
linux-gcp-5.15 (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-azure-fde (Ubuntu package)
kernel-tools
kernel-64k-devel
kernel-64k-debug-devel
kernel-64k-debug
kernel-64k
python3-perf
perf
kernel-tools-libs-devel
kernel-tools-libs
kernel-headers
kernel-devel
kernel-debug-devel
kernel-debug
kernel
bpftool
linux-aws-fips (Ubuntu package)
linux-lowlatency (Ubuntu package)
linux-hwe-6.8 (Ubuntu package)
linux-xilinx (Ubuntu package)
linux-gcp (Ubuntu package)
linux-ibm (Ubuntu package)
linux-nvidia-lowlatency (Ubuntu package)
linux-gcp-fips (Ubuntu package)
linux-gcp-6.8 (Ubuntu package)
linux-azure-6.8 (Ubuntu package)
linux-raspi-realtime (Ubuntu package)
linux-realtime-6.8 (Ubuntu package)
linux-oem-6.14 (Ubuntu package)
linux-realtime-6.14 (Ubuntu package)
linux-aws-6.14 (Ubuntu package)
linux-gcp-6.14 (Ubuntu package)
How to mitigate CVE-2025-38562
Install update from vendor's repository.
Linux kernel - update to 6.16.1
linux (Ubuntu package) - addressed in versions 5.15.0.184.155, 5.15.0-184.194, 5.15.0-184.194~20.04.1, 5.15.0.186.166, 5.15.0-186.196, 5.15.0-186.196~20.04.1, 5.15.0.1075.78, 5.15.0-1075.79, 5.15.0.1095.94, 5.15.0-1095.103, 5.15.0.1104.100, 5.15.0-1104.109, 5.15.0.1108.107, 5.15.0-1108.114, 5.15.0.1111.115, 5.15.0-1111.120+fips1, 5.15.0.1112.102, 5.15.0.1112.109, 5.15.0-1112.122, 5.15.0-1112.122+fips1, 6.8.0-100.100, 6.8.0-1047.51, 6.14.0-36.36, 6.14.0-36.36~24.04.1, 6.14.0-1016.16~24.04.1, 6.14.0-1017.17, 6.14.0-1020.21
linux-aws (Ubuntu package) - addressed in versions 5.15.0.186.109, 5.15.0-186.196+fips1, 5.15.0.1106.103, 5.15.0-1106.110, 5.15.0.1107.107, 5.15.0-1107.108, 5.15.0.1112.108, 5.15.0.1112.115, 5.15.0-1112.119, 5.15.0-1112.119+fips1, 5.15.0-1112.119~20.04.1, 6.8.0-1030.33, 6.8.0-1043.44, 6.8.0-1043.44~22.04.1, 6.8.0-1046.49~22.04.1
linux-nvidia-tegra (Ubuntu package) - addressed in versions 5.15.0-1053.53, 5.15.0.1053.55, 5.15.0.1064.64, 5.15.0-1064.66
linux-nvidia-tegra-5.15 (Ubuntu package) - update to 5.15.0-1064.66~20.04.1
linux-intel-iot-realtime (Ubuntu package) - addressed in versions 5.15.0-1104.106, 5.15.0.1104.108, 5.15.0-1107.113~20.04.1
linux-ibm-5.15 (Ubuntu package) - update to 5.15.0-1106.110~20.04.1
linux-intel-iotg (Ubuntu package) - addressed in versions 5.15.0.1107.106, 5.15.0-1107.113
linux-azure (Ubuntu package) - addressed in versions 5.15.0.1109.105, 5.15.0-1109.115, 5.15.0.1117.115, 5.15.0-1117.126, 6.8.0-1046.52, 6.14.0-1017.17, 6.14.0-1017.17~24.04.1
linux-azure-5.15 (Ubuntu package) - addressed in versions 5.15.0-1109.115~20.04.1, 5.15.0-1117.126~20.04.1, 5.15.0-1117.126~20.04.2
linux-gcp-5.15 (Ubuntu package) - update to 5.15.0-1112.122~20.04.1
linux-azure-fips (Ubuntu package) - addressed in versions 5.15.0.1117.102, 5.15.0-1117.126+fips1, 6.8.0-1046.52+fips1
linux-azure-fde (Ubuntu package) - update to 5.15.0-1117.126
kernel-tools - update to 6.6.102-5
kernel-64k-devel - update to 6.6.102-5
kernel-64k-debug-devel - update to 6.6.102-5
kernel-64k-debug - update to 6.6.102-5
kernel-64k - update to 6.6.102-5
python3-perf - update to 6.6.102-5
perf - update to 6.6.102-5
kernel-tools-libs-devel - update to 6.6.102-5
kernel-tools-libs - update to 6.6.102-5
kernel-headers - update to 6.6.102-5
kernel-devel - update to 6.6.102-5
kernel-debug-devel - update to 6.6.102-5
kernel-debug - update to 6.6.102-5
kernel - update to 6.6.102-5
bpftool - update to 6.6.102-5
linux-aws-fips (Ubuntu package) - addressed in versions 6.8.0-100.100+fips1, 6.8.0-1046.49+fips1
linux-lowlatency (Ubuntu package) - update to 6.8.0-100.100.1
linux-hwe-6.8 (Ubuntu package) - addressed in versions 6.8.0-100.100.1~22.04.1, 6.8.0-100.100~22.04.1
linux-xilinx (Ubuntu package) - addressed in versions 6.8.0.1023.24, 6.8.0-1023.24
linux-gcp (Ubuntu package) - addressed in versions 6.8.0-1043.48, 6.8.0-1047.50~22.04.2
linux-ibm (Ubuntu package) - addressed in versions 6.8.0-1044.44, 6.8.0-1044.44~22.04.1
linux-nvidia-lowlatency (Ubuntu package) - update to 6.8.0-1046.49.1
linux-gcp-fips (Ubuntu package) - update to 6.8.0-1047.50+fips1
linux-gcp-6.8 (Ubuntu package) - update to 6.8.0-1047.50~22.04.2
linux-azure-6.8 (Ubuntu package) - update to 6.8.0-1051.57~22.04.1
linux-raspi-realtime (Ubuntu package) - addressed in versions 6.8.0-2037.38, 6.8.1-1041.42
linux-realtime-6.8 (Ubuntu package) - update to 6.8.1-1041.42~22.04.1
linux-oem-6.14 (Ubuntu package) - update to 6.14.0-1016.16
linux-realtime-6.14 (Ubuntu package) - update to 6.14.0-1016.16~24.04.1
linux-aws-6.14 (Ubuntu package) - update to 6.14.0-1017.17~24.04.1
linux-gcp-6.14 (Ubuntu package) - addressed in versions 6.14.0-1018.18, 6.14.0-1020.21~24.04.1
linux (Ubuntu package) - addressed in versions 5.15.0.184.155, 5.15.0-184.194, 5.15.0-184.194~20.04.1, 5.15.0.186.166, 5.15.0-186.196, 5.15.0-186.196~20.04.1, 5.15.0.1075.78, 5.15.0-1075.79, 5.15.0.1095.94, 5.15.0-1095.103, 5.15.0.1104.100, 5.15.0-1104.109, 5.15.0.1108.107, 5.15.0-1108.114, 5.15.0.1111.115, 5.15.0-1111.120+fips1, 5.15.0.1112.102, 5.15.0.1112.109, 5.15.0-1112.122, 5.15.0-1112.122+fips1, 6.8.0-100.100, 6.8.0-1047.51, 6.14.0-36.36, 6.14.0-36.36~24.04.1, 6.14.0-1016.16~24.04.1, 6.14.0-1017.17, 6.14.0-1020.21
linux-aws (Ubuntu package) - addressed in versions 5.15.0.186.109, 5.15.0-186.196+fips1, 5.15.0.1106.103, 5.15.0-1106.110, 5.15.0.1107.107, 5.15.0-1107.108, 5.15.0.1112.108, 5.15.0.1112.115, 5.15.0-1112.119, 5.15.0-1112.119+fips1, 5.15.0-1112.119~20.04.1, 6.8.0-1030.33, 6.8.0-1043.44, 6.8.0-1043.44~22.04.1, 6.8.0-1046.49~22.04.1
linux-nvidia-tegra (Ubuntu package) - addressed in versions 5.15.0-1053.53, 5.15.0.1053.55, 5.15.0.1064.64, 5.15.0-1064.66
linux-nvidia-tegra-5.15 (Ubuntu package) - update to 5.15.0-1064.66~20.04.1
linux-intel-iot-realtime (Ubuntu package) - addressed in versions 5.15.0-1104.106, 5.15.0.1104.108, 5.15.0-1107.113~20.04.1
linux-ibm-5.15 (Ubuntu package) - update to 5.15.0-1106.110~20.04.1
linux-intel-iotg (Ubuntu package) - addressed in versions 5.15.0.1107.106, 5.15.0-1107.113
linux-azure (Ubuntu package) - addressed in versions 5.15.0.1109.105, 5.15.0-1109.115, 5.15.0.1117.115, 5.15.0-1117.126, 6.8.0-1046.52, 6.14.0-1017.17, 6.14.0-1017.17~24.04.1
linux-azure-5.15 (Ubuntu package) - addressed in versions 5.15.0-1109.115~20.04.1, 5.15.0-1117.126~20.04.1, 5.15.0-1117.126~20.04.2
linux-gcp-5.15 (Ubuntu package) - update to 5.15.0-1112.122~20.04.1
linux-azure-fips (Ubuntu package) - addressed in versions 5.15.0.1117.102, 5.15.0-1117.126+fips1, 6.8.0-1046.52+fips1
linux-azure-fde (Ubuntu package) - update to 5.15.0-1117.126
kernel-tools - update to 6.6.102-5
kernel-64k-devel - update to 6.6.102-5
kernel-64k-debug-devel - update to 6.6.102-5
kernel-64k-debug - update to 6.6.102-5
kernel-64k - update to 6.6.102-5
python3-perf - update to 6.6.102-5
perf - update to 6.6.102-5
kernel-tools-libs-devel - update to 6.6.102-5
kernel-tools-libs - update to 6.6.102-5
kernel-headers - update to 6.6.102-5
kernel-devel - update to 6.6.102-5
kernel-debug-devel - update to 6.6.102-5
kernel-debug - update to 6.6.102-5
kernel - update to 6.6.102-5
bpftool - update to 6.6.102-5
linux-aws-fips (Ubuntu package) - addressed in versions 6.8.0-100.100+fips1, 6.8.0-1046.49+fips1
linux-lowlatency (Ubuntu package) - update to 6.8.0-100.100.1
linux-hwe-6.8 (Ubuntu package) - addressed in versions 6.8.0-100.100.1~22.04.1, 6.8.0-100.100~22.04.1
linux-xilinx (Ubuntu package) - addressed in versions 6.8.0.1023.24, 6.8.0-1023.24
linux-gcp (Ubuntu package) - addressed in versions 6.8.0-1043.48, 6.8.0-1047.50~22.04.2
linux-ibm (Ubuntu package) - addressed in versions 6.8.0-1044.44, 6.8.0-1044.44~22.04.1
linux-nvidia-lowlatency (Ubuntu package) - update to 6.8.0-1046.49.1
linux-gcp-fips (Ubuntu package) - update to 6.8.0-1047.50+fips1
linux-gcp-6.8 (Ubuntu package) - update to 6.8.0-1047.50~22.04.2
linux-azure-6.8 (Ubuntu package) - update to 6.8.0-1051.57~22.04.1
linux-raspi-realtime (Ubuntu package) - addressed in versions 6.8.0-2037.38, 6.8.1-1041.42
linux-realtime-6.8 (Ubuntu package) - update to 6.8.1-1041.42~22.04.1
linux-oem-6.14 (Ubuntu package) - update to 6.14.0-1016.16
linux-realtime-6.14 (Ubuntu package) - update to 6.14.0-1016.16~24.04.1
linux-aws-6.14 (Ubuntu package) - update to 6.14.0-1017.17~24.04.1
linux-gcp-6.14 (Ubuntu package) - addressed in versions 6.14.0-1018.18, 6.14.0-1020.21~24.04.1
External References
- https://git.kernel.org/stable/c/015ef163d65496ae3ba6192c96140a22743f0353
- https://git.kernel.org/stable/c/2a30ed6428ce83afedca1a6c5c5c4247bcf12d0e
- https://git.kernel.org/stable/c/96a82e19434a2522525baab59c33332658bc7653
- https://git.kernel.org/stable/c/9b493ab6f35178afd8d619800df9071992f715de
- https://git.kernel.org/stable/c/9c2dbbc959e1fcc6f603a1a843e9cf743ba383bb
- https://git.kernel.org/stable/c/d79c8bebaa622ee223128be7c66d8aaeeb634a57
- https://www.zerodayinitiative.com/advisories/ZDI-25-917/
Related Security Bulletins
- NULL pointer dereference in Linux kernel smb server
- Anolis OS update for kernel:6.6
- Ubuntu update for linux-oem-6.14
- Ubuntu update for linux-realtime-6.14
- Ubuntu update for linux
- Ubuntu update for linux-aws-6.14
- Ubuntu update for linux-gcp-6.14
- Ubuntu update for linux-azure
- Ubuntu update for linux
- Ubuntu update for linux-realtime-6.8
- Ubuntu update for linux-gcp-6.8
- Ubuntu update for linux-aws-fips
- Ubuntu update for linux-raspi-realtime
- Ubuntu update for linux-aws
- Ubuntu update for linux-gcp-fips
- Ubuntu update for linux-hwe-6.8
- Ubuntu update for linux-lowlatency
- Ubuntu update for linux-gcp
- Ubuntu update for linux-nvidia-lowlatency
- Ubuntu update for linux-xilinx
- Ubuntu update for linux-ibm
- Ubuntu update for linux-azure-fips
- Ubuntu update for linux-azure
- Ubuntu update for linux-azure-6.8
- Ubuntu update for linux-nvidia-tegra-5.15
- Ubuntu update for linux
- Ubuntu update for linux-ibm-5.15
- Ubuntu update for linux-nvidia-tegra
- Ubuntu update for linux-aws
- Ubuntu update for linux-azure-fde
- Ubuntu update for linux-azure
- Ubuntu update for linux-azure-5.15
- Ubuntu update for linux-azure-fips
- Ubuntu update for linux-intel-iot-realtime
- Ubuntu update for linux-intel-iotg
- Ubuntu update for linux-gcp-5.15