dmaengine: Fix a double free in dma_async_device_register
authorLv Yunlong <lyl2019@mail.ustc.edu.cn>
Wed, 31 Mar 2021 01:44:58 +0000 (18:44 -0700)
committerVinod Koul <vkoul@kernel.org>
Mon, 12 Apr 2021 09:35:58 +0000 (15:05 +0530)
commitea45b6008f8095db0cc09ad6e03c7785c2986197
tree36bfe6e35d915dd751f57f802f9067e256109668
parent88cd1d6191b13689094310c2405394e4ce36d061
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: d2fb0a0438384 ("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>
drivers/dma/dmaengine.c