From b027b4de22e3030bb824b40e9cc934c248db9da0 Mon Sep 17 00:00:00 2001 From: Lukas Wunner Date: Wed, 11 Nov 2020 20:07:20 +0100 Subject: [PATCH] spi: bcm2835: Fix use-after-free on unbind commit e1483ac030fb4c57734289742f1c1d38dca61e22 upstream 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 Reported-by: Florian Fainelli Signed-off-by: Lukas Wunner Cc: # v3.10+: 123456789abc: spi: Introduce device-managed SPI controller allocation Cc: # v3.10+ Cc: Vladimir Oltean Tested-by: Florian Fainelli Acked-by: Florian Fainelli Link: https://lore.kernel.org/r/ad66e0a0ad96feb848814842ecf5b6a4539ef35c.1605121038.git.lukas@wunner.de Signed-off-by: Mark Brown [sudip: dev_err_probe() not yet available] Signed-off-by: Sudip Mukherjee --- drivers/spi/spi-bcm2835.c | 18 ++++++------------ 1 file changed, 6 insertions(+), 12 deletions(-) diff --git a/drivers/spi/spi-bcm2835.c b/drivers/spi/spi-bcm2835.c index 9ae1c96f4d3d..5bc97b22491c 100644 --- a/drivers/spi/spi-bcm2835.c +++ b/drivers/spi/spi-bcm2835.c @@ -1264,7 +1264,7 @@ 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; @@ -1284,23 +1284,19 @@ static int bcm2835_spi_probe(struct platform_device *pdev) bs = spi_controller_get_devdata(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 = PTR_ERR(bs->clk); dev_err(&pdev->dev, "could not get clk: %d\n", err); - goto out_controller_put; + return err; } 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); @@ -1330,8 +1326,6 @@ static int bcm2835_spi_probe(struct platform_device *pdev) out_clk_disable: clk_disable_unprepare(bs->clk); -out_controller_put: - spi_controller_put(ctlr); return err; } -- 2.11.0