Merge tag 'dmaengine-fix-4.16-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git...
authorLinus Torvalds <torvalds@linux-foundation.org>
Sun, 25 Mar 2018 17:45:10 +0000 (07:45 -1000)
committerLinus Torvalds <torvalds@linux-foundation.org>
Sun, 25 Mar 2018 17:45:10 +0000 (07:45 -1000)
Pull dmaengine fix from Vinod Koul:
 "One small fix for stm32-dmamux fixing buffer overflow"

* tag 'dmaengine-fix-4.16-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/slave-dma:
  dmaengine: stm32-dmamux: fix a potential buffer overflow

drivers/dma/stm32-dmamux.c

index 4dbb30cf94acb8462cd50b8123c64259a86f31c9..b922db90939a5d9643753bfdc313d9fdbdd2dc33 100644 (file)
@@ -118,14 +118,15 @@ static void *stm32_dmamux_route_allocate(struct of_phandle_args *dma_spec,
        spin_lock_irqsave(&dmamux->lock, flags);
        mux->chan_id = find_first_zero_bit(dmamux->dma_inuse,
                                           dmamux->dma_requests);
-       set_bit(mux->chan_id, dmamux->dma_inuse);
-       spin_unlock_irqrestore(&dmamux->lock, flags);
 
        if (mux->chan_id == dmamux->dma_requests) {
+               spin_unlock_irqrestore(&dmamux->lock, flags);
                dev_err(&pdev->dev, "Run out of free DMA requests\n");
                ret = -ENOMEM;
-               goto error;
+               goto error_chan_id;
        }
+       set_bit(mux->chan_id, dmamux->dma_inuse);
+       spin_unlock_irqrestore(&dmamux->lock, flags);
 
        /* Look for DMA Master */
        for (i = 1, min = 0, max = dmamux->dma_reqs[i];
@@ -173,6 +174,8 @@ static void *stm32_dmamux_route_allocate(struct of_phandle_args *dma_spec,
 
 error:
        clear_bit(mux->chan_id, dmamux->dma_inuse);
+
+error_chan_id:
        kfree(mux);
        return ERR_PTR(ret);
 }