Executive brief
A vulnerability in the Linux kernel's networking component could allow a local user to crash the system. The issue occurs when the system attempts to process certain network packets while a specific type of virtual network interface (BareUDP) is being shut down. This results in a system crash (kernel panic), potentially disrupting services and operations.
Technical details
A NULL pointer dereference exists in the bareudp_fill_metadata_dst() function within drivers/net/bareudp.c. The vulnerability is triggered when the function attempts to pass bareudp->sock to udp_tunnel6_dst_lookup() in the IPv6 path without verifying if the socket exists. Because the socket is NULLed when the device is stopped (bareudp_stop()), calling this function while the device is down leads to a kernel panic. This can be reached via Open vSwitch actions or netlink commands. The fix introduces a NULL check that returns -ESHUTDOWN if the socket is unavailable.
Affected products
- Linux Linux Kernel 5.7 to 6.x
Timeline
- 2026-04-26: other: Patch submitted by developer
- 2026-05-23: patched: Commits merged into stable branches
- 2026-05-27: advisory: CVE published
References
- https://git.kernel.org/stable/c/35a115a204be08f97450b0389413e218268ef4a2
- https://git.kernel.org/stable/c/638905520fc4fae6a80991563f264131545ba3df
- https://git.kernel.org/stable/c/74a02921c48fcd35a7881956c9e5c52b86595f5d
- https://git.kernel.org/stable/c/a0f4e4e8e0f5e24ddd83e3d1221732621cf34636
- https://git.kernel.org/stable/c/aa6c6d9ee064aabfede4402fd1283424e649ca19