AZL-90482

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

net/mlx5e: xsk: Fix DMA and xdpframe leak on XDPTX xmit failure

In the XSK branch of mlx5exmitxdpbuff(), when sq->xmitxdpframe() returns false (e.g. XDPSQ is full), the function returns without unmapping the DMA address or freeing the xdpframe allocated by xdpconvertzctoxdpframe(). The xdpififo push only happens on success, so the completion path cannot recover these entries.

With CONFIGDMAAPI_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 DMATODEVICE] [mapped as phy] WARNING: kernel/dma/debug.c:881 at dmadebugdevicechange+0x127/0x180 ... DMA-API: Mapped at: debugdmamapphys+0x4b/0xd0 dmamapphys+0xfd/0x2d0 mlx5exdphandle+0x5ae/0xac0 [mlx5core] mlx5exskskbfromcqempwrqlinear+0xc4/0x170 [mlx5core] mlx5ehandlerxcqempwrq+0xc1/0x290 [mlx5_core]

Add the missing unmap + xdpreturnframe, matching the cleanup already done in mlx5exdpxmit(). has_frags is rejected earlier in this branch, so no per-frag unmap is needed.