dmaengine: Fix a double free in dma_async_device_register
In the first list_for_each_entry() macro of dma_async_device_register, it gets the chan from list and calls __dma_async_device_channel_register (..,chan). We can see that chan->local is allocated by alloc_percpu() and it is freed chan->local by free_percpu(chan->local) when __dma_async_device_channel_register() failed. But after __dma_async_device_channel_register() failed, the caller will goto err_out and freed the chan->local in the second time by free_percpu(). The cause of this problem is forget to set chan->local to NULL when chan->local was freed in __dma_async_device_channel_register(). My patch sets chan->local to NULL when the callee failed to avoid double free. Fixes: d2fb0a04 ("dmaengine: break out channel registration") Signed-off-by:Lv Yunlong <lyl2019@mail.ustc.edu.cn> Reviewed-by:
Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/20210331014458.3944-1-lyl2019@mail.ustc.edu.cn Signed-off-by:
Vinod Koul <vkoul@kernel.org>
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