Unverified Commit 393f981c authored by Lukas Wunner's avatar Lukas Wunner Committed by Mark Brown
Browse files

spi: rpc-if: Fix use-after-free on unbind 



rpcif_spi_remove() accesses the driver's private data after calling
spi_unregister_controller() even though that function releases the last
reference on the spi_controller and thereby frees the private data.

Fix by switching over to the new devm_spi_alloc_master() helper which
keeps the private data accessible until the driver has unbound.

Fixes: eb8d6d46 ("spi: add Renesas RPC-IF driver")
Signed-off-by: default avatarLukas Wunner <lukas@wunner.de>
Cc: <stable@vger.kernel.org> # v5.9+: 5e844cc3: spi: Introduce device-managed SPI controller allocation
Cc: <stable@vger.kernel.org> # v5.9+
Cc: Sergei Shtylyov <s.shtylyov@omprussia.ru>
Link: https://lore.kernel.org/r/c5da472c28021da2f6517441685cef033d40b140.1607286887.git.lukas@wunner.de


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 5626308b

drivers/spi/spi-rpc-if.c

+2 −7
Original line number Diff line number Diff line
@@ -134,7 +134,7 @@ static int rpcif_spi_probe(struct platform_device *pdev) 
	struct rpcif *rpc;

	int error;



	ctlr = spi_alloc_master(&pdev->dev, sizeof(*rpc));

	ctlr = devm_spi_alloc_master(&pdev->dev, sizeof(*rpc));

	if (!ctlr)

		return -ENOMEM;
@@ -159,13 +159,8 @@ static int rpcif_spi_probe(struct platform_device *pdev) 
	error = spi_register_controller(ctlr);

	if (error) {

		dev_err(&pdev->dev, "spi_register_controller failed\n");

		goto err_put_ctlr;

	}

	return 0;



err_put_ctlr:

		rpcif_disable_rpm(rpc);

	spi_controller_put(ctlr);

	}



	return error;

}