From: Peter Ujfalusi <peter.ujfalusi@ti.com>
Date: Fri, 20 Dec 2019 13:11:00 +0000 (+0200)
Subject: dmaengine: virt-dma: Fix access after free in vchan_complete()
X-Git-Tag: v5.4.9~69
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=fdfd8f9ef2d3a35764e8fabc035bd0bbb382e318;p=platform%2Fkernel%2Flinux-rpi.git

dmaengine: virt-dma: Fix access after free in vchan_complete()

commit 24461d9792c2c706092805ff1b067628933441bd upstream.

vchan_vdesc_fini() is freeing up 'vd' so the access to vd->tx_result is
via already freed up memory.

Move the vchan_vdesc_fini() after invoking the callback to avoid this.

Fixes: 09d5b702b0f97 ("dmaengine: virt-dma: store result on dma descriptor")
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Reviewed-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20191220131100.21804-1-peter.ujfalusi@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/dma/virt-dma.c b/drivers/dma/virt-dma.c
index ec4adf4..256fc66 100644
--- a/drivers/dma/virt-dma.c
+++ b/drivers/dma/virt-dma.c
@@ -104,9 +104,8 @@ static void vchan_complete(unsigned long arg)
 		dmaengine_desc_get_callback(&vd->tx, &cb);
 
 		list_del(&vd->node);
-		vchan_vdesc_fini(vd);
-
 		dmaengine_desc_callback_invoke(&cb, &vd->tx_result);
+		vchan_vdesc_fini(vd);
 	}
 }