In the Linux kernel, the following vulnerability has been resolved: iio: buffer: Make IIO DMA fence release RCU-safe The `dma_fence` docum

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

iio: buffer: Make IIO DMA fence release RCU-safe

The dma_fence documentation states that if a custom release
implementation is provided, the dma_fence object must be freed in an
RCU-safe way. The current iio_dma_fence implementation uses kfree(),
which might result in a use-after-free.

Remove the custom release implementation. This makes the DMA fence core
fall back to dma_fence_free(), which calls kfree_rcu() on the fence.
This requires that the fence be the first member of struct iio_dma_fence.

Using the default release method for extended DMA fence structures is a
common pattern.