vsock/virtio: fix accept queue count leak on transport mismatch

Summary

In the Linux kernel, the following vulnerability has been resolved: vsock/virtio: fix accept queue count leak on transport mismatch virtio_transport_recv_listen() calls sk_acceptq_added() before vsock_assign_transport(). If vsock_assign_transport() fails or selects a different transport, the error path returns without calling sk_acceptq_removed(), permanently incrementing sk_ack_backlog. After approximately backlog+1 such failures, sk_acceptq_is_full() returns true, causing the listener to reject all new connections. Fix by moving sk_acceptq_added() to after the transport validation, matching the pattern used by vmci_transport and hyperv_transport.

Timeline

1. May 28, 2026, 9:40 AM UTCCVE published
2. Oct 15, 2026, 1:21 AM UTCRecord last updated

Affected versions

• Linux Linux

  From c0cfa2d8a788fcf45df5bf4070ab2474c88d543a · fixed in 2ea5d2c79edcc99c7dbe0bb7518f5e1ee2a2391f; From c0cfa2d8a788fcf45df5bf4070ab2474c88d543a · fixed in fd51e810affa38d735d04261e673b2a5fe9c8665; From c0cfa2d8a788fcf45df5bf4070ab2474c88d543a · fixed in f66c7904fb6f0e420a654bc90909e64a25d00896; From c0cfa2d8a788fcf45df5bf4070ab2474c88d543a · fixed in 65c484726e74013a2ec7ba67a34d87760ae8f390; From c0cfa2d8a788fcf45df5bf4070ab2474c88d543a · fixed in 29371f3cc83e2a92265b4768014a30b80234112f; From c0cfa2d8a788fcf45df5bf4070ab2474c88d543a · fixed in e9edf9893cf26d060705c910a9b62d8cc96ed56a; From c0cfa2d8a788fcf45df5bf4070ab2474c88d543a · fixed in 6d3275fc4ed968938e1d556c344798046776668d; From c0cfa2d8a788fcf45df5bf4070ab2474c88d543a · fixed in 52bcb57a4e8a0865a76c587c2451906342ae1b2d

• Linux Linux

  5.5

• KernelLinux

  From 5.5.0 · fixed in 5.10.258; From 5.11.0 · fixed in 5.15.209; From 5.16.0 · fixed in 6.1.175; From 6.2.0 · fixed in 6.6.140; From 6.7.0 · fixed in 6.12.90; From 6.13.0 · fixed in 6.18.32; From 6.19.0 · fixed in 7.0.9

References 8