CVE-2025-21788

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

net: ethernet: ti: am65-cpsw: fix memleak in certain XDP cases

If the XDP program doesnt result in XDP_PASS then we leak the memory allocated by am65_cpsw_build_skb().

It is pointless to allocate SKB memory before running the XDP program as we would be wasting CPU cycles for cases other than XDP_PASS. Move the SKB allocation after evaluating the XDP program result.

This fixes the memleak. A performance boost is seen for XDP_DROP test.

XDP_DROP test: Before: 460256 rx/s 0 err/s After: 784130 rx/s 0 err/s

Weakness

The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.

Affected Software

Potential Mitigations

• Choose a language or tool that provides automatic memory management, or makes manual memory management less error-prone.
• For example, glibc in Linux provides protection against free of invalid pointers.
• When using Xcode to target OS X or iOS, enable automatic reference counting (ARC) [REF-391].
• To help correctly and consistently manage memory when programming in C++, consider using a smart pointer class such as std::auto_ptr (defined by ISO/IEC ISO/IEC 14882:2003), std::shared_ptr and std::unique_ptr (specified by an upcoming revision of the C++ standard, informally referred to as C++ 1x), or equivalent solutions such as Boost.

References

• https://git.kernel.org/stable/c/1bba1d042107167164a0ae3a843fdf650ab005d7
• https://git.kernel.org/stable/c/5db843258de1e4e6b1ef1cbd1797923c9e3de548
• https://git.kernel.org/stable/c/dc11f049612b9d926aca2e55f8dc9d82850d0da3