From: Lv Yunlong lyl2019@mail.ustc.edu.cn
[ Upstream commit ea45b6008f8095db0cc09ad6e03c7785c2986197 ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/dma/dmaengine.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index fe6a460c4373..af3ee288bc11 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -1086,6 +1086,7 @@ static int __dma_async_device_channel_register(struct dma_device *device, kfree(chan->dev); err_free_local: free_percpu(chan->local); + chan->local = NULL; return rc; }