Executive brief
A vulnerability in the Linux kernel's networking subsystem can cause system warnings and the dropping of network logging messages. This affects the Netfilter component, which is responsible for firewalling and packet filtering. While it does not lead to data theft, it can cause minor operational disruptions or interfere with security logging.
Technical details
A vulnerability exists in the nfnetlink_log component of the Linux kernel's Netfilter subsystem. The root cause is that the NLMSG_DONE attribute failed to account for the netlink header size, only accounting for the attribute size. This discrepancy can trigger a kernel WARN splat and result in the dropping of netlink messages. An attacker with local access could potentially trigger this condition to cause a partial denial of service regarding network logging. The issue has been resolved across multiple stable kernel branches by ensuring nlmsg_total_size is used correctly for header accounting.
Affected products
- Linux Linux Kernel 3.10.61 to 3.11, 3.12.34 to 3.13, 3.14.25 to 3.15, 3.18 to 5.10.253, 5.11 to 5.15.203, 5.16 to 6.1.168, 6.2 to 6.6.134, 6.7 to 6.12.81, 6.13 to 6.18.22, 6.19 to 6.19.12, 7.0-rc1 to 7.0-rc7
Timeline
- 2026-03-26: patched: Initial patch authored by Florian Westphal
- 2026-04-13: disclosed
- 2026-04-13: advisory
References
- https://git.kernel.org/stable/c/09883bf257f4243ed5a1fd35078ec6f0d0f3696a
- https://git.kernel.org/stable/c/4ec216410fac9de83c99177a160ebb8d42fad075
- https://git.kernel.org/stable/c/607245c4dbb86d9a10dd8388da0fb82170a99b61
- https://git.kernel.org/stable/c/6b419700e459fbf707ca1543b7c1b57a60fedb73
- https://git.kernel.org/stable/c/6d52a4a0520a6696bdde51caa11f2d6821cd0c01
- https://git.kernel.org/stable/c/761b45c661af48da6a065868d59ab1e1f64fd9b6
- https://git.kernel.org/stable/c/88a8f56e6276f616baad4274c6b8e4683e26e520