CVE-2025-40350

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

net/mlx5e: RX, Fix generating skb from non-linear xdp_buff for striding RQ

XDP programs can change the layout of an xdp_buff through

bpf_xdp_adjust_tail() and bpf_xdp_adjust_head(). Therefore, the driver

cannot assume the size of the linear data area nor fragments. Fix the

bug in mlx5 by generating skb according to xdp_buff after XDP programs

run.

Currently, when handling multi-buf XDP, the mlx5 driver assumes the

layout of an xdp_buff to be unchanged. That is, the linear data area

continues to be empty and fragments remain the same. This may cause

the driver to generate erroneous skb or triggering a kernel

warning. When an XDP program added linear data through

bpf_xdp_adjust_head(), the linear data will be ignored as

mlx5e_build_linear_skb() builds an skb without linear data and then

pull data from fragments to fill the linear data area. When an XDP

program has shrunk the non-linear data through bpf_xdp_adjust_tail

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References