Re: [PATCH] dmaengine: fix NULL pointer in channel unregistration function

From: Vinod Koul
Date: Thu Dec 21 2023 - 11:31:03 EST



On Wed, 13 Dec 2023 17:04:52 +0100, Amelie Delaunay wrote:
> __dma_async_device_channel_register() can fail. In case of failure,
> chan->local is freed (with free_percpu()), and chan->local is nullified.
> When dma_async_device_unregister() is called (because of managed API or
> intentionally by DMA controller driver), channels are unconditionally
> unregistered, leading to this NULL pointer:
> [ 1.318693] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000d0
> [...]
> [ 1.484499] Call trace:
> [ 1.486930] device_del+0x40/0x394
> [ 1.490314] device_unregister+0x20/0x7c
> [ 1.494220] __dma_async_device_channel_unregister+0x68/0xc0
>
> [...]

Applied, thanks!

[1/1] dmaengine: fix NULL pointer in channel unregistration function
commit: f5c24d94512f1b288262beda4d3dcb9629222fc7

Best regards,
--
~Vinod