spi: bcm2835: Fix use-after-free on unbind (e1483ac0) · Commits · 戴 / test

bcm2835_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: ("spi: add driver for BCM2835") Reported-by:

Sascha Hauer <s.hauer@pengutronix.de> Reported-by:

Florian Fainelli <f.fainelli@gmail.com> Signed-off-by:

Lukas Wunner <lukas@wunner.de> Cc: <stable@vger.kernel.org> # v3.10+: 123456789abc: spi: Introduce device-managed SPI controller allocation Cc: <stable@vger.kernel.org> # v3.10+ Cc: Vladimir Oltean <olteanv@gmail.com> Tested-by:

Florian Fainelli <f.fainelli@gmail.com> Acked-by:

Florian Fainelli <f.fainelli@gmail.com> Link: https://lore.kernel.org/r/ad66e0a0ad96feb848814842ecf5b6a4539ef35c.1605121038.git.lukas@wunner.de Signed-off-by:

Mark Brown <broonie@kernel.org>

drivers/spi/spi-bcm2835.c

+8 −16

Original line number	Diff line number	Diff line
		@@ -1278,7 +1278,7 @@ static int bcm2835_spi_probe(struct platform_device *pdev)
		struct bcm2835_spi *bs;
		int err;

		ctlr = spi_alloc_master(&pdev->dev, ALIGN(sizeof(*bs),
		ctlr = devm_spi_alloc_master(&pdev->dev, ALIGN(sizeof(*bs),
		dma_get_cache_alignment()));
		if (!ctlr)
		return -ENOMEM;
		@@ -1299,23 +1299,17 @@ static int bcm2835_spi_probe(struct platform_device *pdev)
		bs->ctlr = ctlr;

		bs->regs = devm_platform_ioremap_resource(pdev, 0);
		if (IS_ERR(bs->regs)) {
		err = PTR_ERR(bs->regs);
		goto out_controller_put;
		}
		if (IS_ERR(bs->regs))
		return PTR_ERR(bs->regs);

		bs->clk = devm_clk_get(&pdev->dev, NULL);
		if (IS_ERR(bs->clk)) {
		err = dev_err_probe(&pdev->dev, PTR_ERR(bs->clk),
		if (IS_ERR(bs->clk))
		return dev_err_probe(&pdev->dev, PTR_ERR(bs->clk),
		"could not get clk\n");
		goto out_controller_put;
		}

		bs->irq = platform_get_irq(pdev, 0);
		if (bs->irq <= 0) {
		err = bs->irq ? bs->irq : -ENODEV;
		goto out_controller_put;
		}
		if (bs->irq <= 0)
		return bs->irq ? bs->irq : -ENODEV;

		clk_prepare_enable(bs->clk);

		@@ -1349,8 +1343,6 @@ out_dma_release:
		bcm2835_dma_release(ctlr, bs);
		out_clk_disable:
		clk_disable_unprepare(bs->clk);
		out_controller_put:
		spi_controller_put(ctlr);
		return err;
		}

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