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spi: bcm2835: Fix use-after-free on unbind

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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: f8043872e796 ("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>
This commit is contained in:
Lukas Wunner 2020-11-11 20:07:20 +01:00 committed by Mark Brown
parent 5e844cc37a
commit e1483ac030
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GPG Key ID: 24D68B725D5487D0
1 changed files with 8 additions and 16 deletions
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22
drivers/spi/spi-bcm2835.c
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@ -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;
}