This is a note to let you know that I've just added the patch titled spi: bcm2835: Fix use-after-free on unbind to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: spi-bcm2835-fix-use-after-free-on-unbind.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Thu Dec 10 01:41:37 PM CET 2020 From: Lukas Wunner <lukas@xxxxxxxxx> Date: Sun, 6 Dec 2020 13:46:02 +0100 Subject: spi: bcm2835: Fix use-after-free on unbind To: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: Mark Brown <broonie@xxxxxxxxxx>, Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx>, stable@xxxxxxxxxxxxxxx Message-ID: <ef79f82544556ed860dea61bfaeae93b62ab15ae.1607258638.git.lukas@xxxxxxxxx> From: Lukas Wunner <lukas@xxxxxxxxx> [ Upstream commit e1483ac030fb4c57734289742f1c1d38dca61e22 ] 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@xxxxxxxxxxxxxx> Reported-by: Florian Fainelli <f.fainelli@xxxxxxxxx> Signed-off-by: Lukas Wunner <lukas@xxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> # v3.10+: 5e844cc37a5c: spi: Introduce device-managed SPI controller allocation Cc: <stable@xxxxxxxxxxxxxxx> # v3.10+ Cc: Vladimir Oltean <olteanv@xxxxxxxxx> Tested-by: Florian Fainelli <f.fainelli@xxxxxxxxx> Acked-by: Florian Fainelli <f.fainelli@xxxxxxxxx> Link: https://lore.kernel.org/r/ad66e0a0ad96feb848814842ecf5b6a4539ef35c.1605121038.git.lukas@xxxxxxxxx Signed-off-by: Mark Brown <broonie@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/spi/spi-bcm2835.c | 15 +++++---------- 1 file changed, 5 insertions(+), 10 deletions(-) --- a/drivers/spi/spi-bcm2835.c +++ b/drivers/spi/spi-bcm2835.c @@ -737,7 +737,7 @@ static int bcm2835_spi_probe(struct plat struct resource *res; int err; - master = spi_alloc_master(&pdev->dev, sizeof(*bs)); + master = devm_spi_alloc_master(&pdev->dev, sizeof(*bs)); if (!master) { dev_err(&pdev->dev, "spi_alloc_master() failed\n"); return -ENOMEM; @@ -759,23 +759,20 @@ static int bcm2835_spi_probe(struct plat res = platform_get_resource(pdev, IORESOURCE_MEM, 0); bs->regs = devm_ioremap_resource(&pdev->dev, res); - if (IS_ERR(bs->regs)) { - err = PTR_ERR(bs->regs); - goto out_master_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_master_put; + return err; } bs->irq = platform_get_irq(pdev, 0); if (bs->irq <= 0) { dev_err(&pdev->dev, "could not get IRQ: %d\n", bs->irq); - err = bs->irq ? bs->irq : -ENODEV; - goto out_master_put; + return bs->irq ? bs->irq : -ENODEV; } clk_prepare_enable(bs->clk); @@ -803,8 +800,6 @@ static int bcm2835_spi_probe(struct plat out_clk_disable: clk_disable_unprepare(bs->clk); -out_master_put: - spi_master_put(master); return err; } Patches currently in stable-queue which might be from lukas@xxxxxxxxx are queue-4.9/spi-fix-controller-unregister-order-harder.patch queue-4.9/spi-bcm-qspi-fix-use-after-free-on-unbind.patch queue-4.9/spi-bcm2835-fix-use-after-free-on-unbind.patch queue-4.9/spi-bcm2835-release-the-dma-channel-if-probe-fails-after-dma_init.patch queue-4.9/spi-introduce-device-managed-spi-controller-allocation.patch