iio: buffer: Tie IIO dma fence lock lifetime to the fence

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The `iio_dma_fence` implementation currently uses a lock embedded in the
`iio_dmabuf_priv`. But the `iio_dma_fence` can outlive the
`iio_dmabuf_priv`, which can cause a use-after-free.

Tie the lifetime of the lock to the lifetime of the fence by embedding them
in the same struct.

We can't just hold a reference to the `iio_dmabuf_priv` from the
`iio_dma_fence` since `iio_buffer_dmabuf_release()` might sleep and the
fence release callback is not allowed to sleep.

Note that the `dma_fence` framework now has an internal lock that gets used
when the passing `NULL` for `lock` in `dma_fence_init()`, but in order to
allow this patch to be backportable use an external lock.

Reported-by: codex:gpt-5.6
Fixes: 3e26d9f08f ("iio: core: Add new DMABUF interface infrastructure")
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>

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Lars-Peter Clausen 2026-07-15 08:42:44 -07:00 • committed by Jonathan Cameron

parent 6288b593e7

commit f25ec4627d

1 changed files with 4 additions and 5 deletions

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drivers/iio/industrialio-buffer.c

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