CVE-2026-90063

Description

In the Linux kernel, the following vulnerability has been resolved: virtio-net: Ensure that TCP packets don't overflow gso_segs The user can specify any gso_size in a packet crafted with an AF_PACKET PACKET_VNET_HDR socket, even smaller than TCP_MIN_GSO_SIZE = 8. At the same time, GSO_MAX_SIZE = 8 * GSO_MAX_SEGS = 8 * 65535. When the user crafts a packet with gso_size < 8, there is a risk for partial GSO to overflow the 16-bit gso_segs field when dividing the SKB length by gso_size. Adjust gso_size of TCP packets to be at least TCP_MIN_GSO_SIZE = 8. Keep gso_size of UDP GSO packets, as gso_size=1 is valid and explicitly tested at tools/testing/selftests/net/tun.c:649.

References

• https://git.kernel.org/stable/c/0e5ed3b98d1d8d251acfdccfeaa607453ad12954
• https://git.kernel.org/stable/c/29bd12c7c5f9d6cf855b87bace18f71e9607f9e8
• https://git.kernel.org/stable/c/339f47ae04dcc6b5a730dd6bc70dddc8937c3260
• https://git.kernel.org/stable/c/75c271c48f483af678e514734e10b2452410e08c
• https://git.kernel.org/stable/c/8f6667a081887c2b59c6f3dd86c1789ada563762