CVE-2025-38413 Information

Jul 26, 2025 cve

Description

In the Linux kernel the following vulnerability has been resolved:

virtio-net: xsk: rx: fix the frame’s length check

When calling buf_to_xdp the len argument is the frame data’s length without virtio header’s length (vi->hdr_len). We check that len with

xsk_pool_get_rx_frame_size() + vi->hdr_len

to ensure the provided len does not larger than the allocated chunk size. The additional vi->hdr_len is because in virtnet_add_recvbuf_xsk we use part of XDP_PACKET_HEADROOM for virtio header and ask the vhost to start placing data from

hard_start + XDP_PACKET_HEADROOM - vi->hdr_len

not hard_start + XDP_PACKET_HEADROOM

But the first buffer has virtio_header so the maximum frame’s length in the first buffer can only be

xsk_pool_get_rx_frame_size()

not xsk_pool_get_rx_frame_size() + vi->hdr_len

like in the current check.

This commit adds an additional argument to buf_to_xdp differentiate between the first buffer and other ones to correctly calculate the maximum frame’s length.

Reference

https://git.kernel.org/stable/c/5177373c31318c3c6a190383bfd232e6cf565c36 https://git.kernel.org/stable/c/6013bb6bc24c2cac3f45b37a15b71b232a5b00ff https://git.kernel.org/stable/c/892f6ed9a4a38bb3360fdff091b9241cfa105b61

CNNVD-202507-3242 (Published: 2025-07-25)

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