CVE-2026-53229

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

net/mlx5e: xsk: Fix DMA and xdp_frame leak on XDP_TX xmit failure

In the XSK branch of mlx5e_xmit_xdp_buff(), when sq->xmit_xdp_frame() returns false (e.g. XDPSQ is full), the function returns without unmapping the DMA address or freeing the xdp_frame allocated by xdp_convert_zc_to_xdp_frame(). The xdpi_fifo push only happens on success, so the completion path cannot recover these entries.

With CONFIG_DMA_API_DEBUG=y, the leak surfaces on driver unbind:

DMA-API: pci 0000:08:00.0: device driver has pending DMA allocations while released from device [count=1116] One of leaked entries details: [device address=0x000000010ffd7028] [size=1534 bytes] [mapped with DMA_TO_DEVICE] [mapped as phy] WARNING: kernel/dma/debug.c:881 at dma_debug_device_change+0x127/0x180 … DMA-API: Mapped at: debug_dma_map_phys+0x4b/0xd0 dma_map_phys+0xfd/0x2d0 mlx5e_xdp_handle+0x5ae/0xac0 [mlx5_core] mlx5e_xsk_skb_from_cqe_mpwrq_linear+0xc4/0x170 [mlx5_core] mlx5e_handle_rx_cqe_mpwrq+0xc1/0x290 [mlx5_core]

Add the missing unmap + xdp_return_frame, matching the cleanup already done in mlx5e_xdp_xmit(). has_frags is rejected earlier in this branch, so no per-frag unmap is needed.

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/0aabca726b43d833721034e97d99efcc8237b22a
• https://git.kernel.org/stable/c/2789b74ae1f4b68333c9d5eec2f3354d07b16e61
• https://git.kernel.org/stable/c/7b3eeba50fbc3b45f279037c29a87a90e8bac1e1
• https://git.kernel.org/stable/c/b69004f5a6ad32da84d8aa5b23b9c0caafe6252e