NULL pointer dereference in Linux kernel - CVE-2025-21798

Vulnerability identifier: #VU105139

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-2025-21798

CWE-ID: CWE-476

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to NULL pointer dereference within the device_attr_simple_avc() and device_attr_legacy_avc() functions in drivers/firewire/device-attribute-test.c. A local user can perform a denial of service (DoS) attack.

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-ibm (Ubuntu package)
linux-hwe-6.8 (Ubuntu package)
linux-aws-6.8 (Ubuntu package)
linux-azure (Ubuntu package)
linux-raspi (Ubuntu package)
linux-gcp (Ubuntu package)
linux-raspi-realtime (Ubuntu package)
linux-realtime (Ubuntu package)
linux-lowlatency (Ubuntu package)
linux-aws (Ubuntu package)

Install update from vendor's website.

Linux kernel - update to 6.12.13
linux (Ubuntu package) - addressed in versions 6.8.0-64.67, 6.8.0-1031.31, 6.8.0-1032.34~22.04.1, 6.11.0-26.26, 6.11.0-26.26~24.04.1, 6.11.0-1010.10, 6.11.0-1013.13, 6.11.0-1015.15, 6.11.0-1015.15~24.04.1, 6.11.0-1022.22
linux-ibm (Ubuntu package) - addressed in versions 6.8.0-64.67.1, 6.8.0-64.67.1~22.04.1, 6.8.0-1029.29, 6.8.0-1029.29~22.04.1
linux-hwe-6.8 (Ubuntu package) - update to 6.8.0-64.67~22.04.1
linux-aws-6.8 (Ubuntu package) - addressed in versions 6.8.0-1015.17, 6.8.0-1028.32, 6.8.0-1029.30, 6.8.0-1029.30~22.04.1, 6.8.0-1031.34, 6.8.0-1031.34.1, 6.8.0-1031.34~22.04.1, 6.8.0-1032.34~22.04.1
linux-azure (Ubuntu package) - addressed in versions 6.8.0-1022.23, 6.8.0-1034.39, 6.8.0-1034.39~22.04.1
linux-raspi (Ubuntu package) - update to 6.8.0-1031.35
linux-gcp (Ubuntu package) - addressed in versions 6.8.0-1033.35, 6.8.0-1033.35~22.04.1
linux-raspi-realtime (Ubuntu package) - update to 6.8.0-2026.27
linux-realtime (Ubuntu package) - update to 6.8.1-1025.26
linux-lowlatency (Ubuntu package) - addressed in versions 6.11.0-1014.15, 6.11.0-1014.15~24.04.1, 6.11.0-1016.17
linux-aws (Ubuntu package) - update to 6.11.0-1014.15

• https://git.kernel.org/stable/c/352fafe97784e81a10a7c74bd508f71a19b53c2a
• https://git.kernel.org/stable/c/70fcb25472d90dd3b87cbee74b9eb68670b0c7b8
• https://git.kernel.org/stable/c/c6896bf4c611c3dd126f3e03685f2360a18b3d6f
• https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.12.13

• NULL pointer dereference in Linux kernel firewire driver
• Ubuntu update for linux
• Ubuntu update for linux-aws
• Ubuntu update for linux-lowlatency
• Ubuntu update for linux-hwe-6.8
• Ubuntu update for linux-realtime
• Ubuntu update for linux
• Ubuntu update for linux-ibm
• Ubuntu update for linux-aws-6.8
• Ubuntu update for linux-gcp
• Ubuntu update for linux-raspi-realtime
• Ubuntu update for linux-raspi
• Ubuntu update for linux-azure