[PATCH] spi: davinci: Fix use-after-free on unbind

From: Lukas Wunner <lukas@wunner.de>
To: Mark Brown <broonie@kernel.org>
Cc: linux-spi@vger.kernel.org, Peter Ujfalusi <peter.ujfalusi@ti.com>
Subject: [PATCH] spi: davinci: Fix use-after-free on unbind
Date: Sun, 8 Nov 2020 23:41:00 +0100	[thread overview]
Message-ID: <dd060534490eca5e946eb9165916542b01a9358d.1604874488.git.lukas@wunner.de> (raw)

davinci_spi_remove() accesses the driver's private data after it's been
freed with spi_master_put().

Fix by moving the spi_master_put() to the end of the function.

Fixes: fe5fd2540947 ("spi: davinci: Use dma_request_chan() for requesting DMA channel")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: <stable@vger.kernel.org> # v4.7+
Cc: Peter Ujfalusi <peter.ujfalusi@ti.com>
---
 drivers/spi/spi-davinci.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/spi/spi-davinci.c b/drivers/spi/spi-davinci.c
index 818f2b22875d..7453a1dbbc06 100644
--- a/drivers/spi/spi-davinci.c
+++ b/drivers/spi/spi-davinci.c
@@ -1040,13 +1040,13 @@ static int davinci_spi_remove(struct platform_device *pdev)
 	spi_bitbang_stop(&dspi->bitbang);
 
 	clk_disable_unprepare(dspi->clk);
-	spi_master_put(master);
 
 	if (dspi->dma_rx) {
 		dma_release_channel(dspi->dma_rx);
 		dma_release_channel(dspi->dma_tx);
 	}
 
+	spi_master_put(master);
 	return 0;
 }
 
-- 
2.28.0

