Unverified Commit 393f981c authored Dec 07, 2020 by Lukas Wunner Committed by Mark Brown Dec 07, 2020

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: Lukas 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: Mark 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;
		}

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