Executive brief
A vulnerability was identified in the Linux kernel's NetLabel component, which manages security labels for network traffic. A local attacker could send a specially crafted request that causes the system to read network address information incorrectly, potentially leading to a system crash or instability. This issue affects the reliability of network security policy enforcement on the system.
Technical details
A vulnerability in net/netlabel/netlabel_unlabeled.c exists due to insufficient validation of attribute lengths in netlbl_unlabel_addrinfo_get(). While the function validated the address attribute length, it failed to independently verify the corresponding mask attribute length. A crafted Generic Netlink request could provide a valid IPv4/IPv6 address with a shorter-than-expected mask attribute, causing the kernel to read past the end of the provided buffer when treating it as a full struct in_addr or struct in6_addr. The fix implements NLA_POLICY_EXACT_LEN() to enforce strict length requirements during Netlink policy validation.
Affected products
- Linux Linux 2.6.25 to 6.9.x
Timeline
- 2026-06-25: disclosed
- 2026-06-19: patched
References
- https://git.kernel.org/stable/c/07a18f5c90dd3d586b73242f5a5bbf0a72f2fdc6
- https://git.kernel.org/stable/c/0c4bb32ad7fdc2dc6a8050f41eb04d4bda56b6c8
- https://git.kernel.org/stable/c/672f0f3b8f875ffe6525a37847eafa7648c4c0c6
- https://git.kernel.org/stable/c/71c52da13c3737493b42d20d9f33de34e03b3156
- https://git.kernel.org/stable/c/95bda3eac0b1454c2cee98d58d9ba6dd8391e843
- https://git.kernel.org/stable/c/975a84fd741440853380d37465b6e226cf47254c
- https://git.kernel.org/stable/c/9772589b57e44aedc240211c5c3f7a684a034d3a