CVE-2026-90063 PUBLISHED

virtio-net: Ensure that TCP packets don't overflow gso_segs

Assigner: Linux
Reserved: 11.09.2026 Published: 17.09.2026 Updated: 17.09.2026

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.

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from 7c6d2ecbda83150b2036a2b36b21381ad4667762 to d3d111fe809773edbb4ae121e36253b7d683509a (excl.)
  • affected from 7c6d2ecbda83150b2036a2b36b21381ad4667762 to 8f6667a081887c2b59c6f3dd86c1789ada563762 (excl.)
  • affected from 7c6d2ecbda83150b2036a2b36b21381ad4667762 to 339f47ae04dcc6b5a730dd6bc70dddc8937c3260 (excl.)
  • affected from 7c6d2ecbda83150b2036a2b36b21381ad4667762 to 29bd12c7c5f9d6cf855b87bace18f71e9607f9e8 (excl.)
  • affected from 7c6d2ecbda83150b2036a2b36b21381ad4667762 to 0e5ed3b98d1d8d251acfdccfeaa607453ad12954 (excl.)
  • affected from 7c6d2ecbda83150b2036a2b36b21381ad4667762 to 75c271c48f483af678e514734e10b2452410e08c (excl.)
  • affected from 7c6d2ecbda83150b2036a2b36b21381ad4667762 to c27c449d455aafd9018a3cbab150f1c42c87923f (excl.)
  • Version bfbaf151efe491e30697e21c8b7ae1b615480873 is affected
  • Version 6c83456601e65a6dd371ddf595510183d198e9b1 is affected
  • Version b3ebd9830c6026c98f03f7047c9d608573773f13 is affected
  • Version b96fb681ca789629b8ba3da99ca3b2e6fa807f0a is affected
  • affected from 4.14.187 to 4.15 (excl.)
  • affected from 4.19.131 to 4.20 (excl.)
  • affected from 5.4.46 to 5.5 (excl.)
  • affected from 5.6.18 to 5.7 (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 5.7 is affected
  • unaffected from 0 to 5.7 (excl.)
  • unaffected from 5.15.221 to 5.15.* (incl.)
  • unaffected from 6.1.188 to 6.1.* (incl.)
  • unaffected from 6.6.157 to 6.6.* (incl.)
  • unaffected from 6.12.110 to 6.12.* (incl.)
  • unaffected from 6.18.52 to 6.18.* (incl.)
  • unaffected from 7.2.6 to 7.2.* (incl.)
  • unaffected from 7.3-rc1 to * (incl.)

References