This is a note to let you know that I've just added the patch titled spi: bcm2835aux: Fix use-after-free on unbind to the 5.9-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-bcm2835aux-fix-use-after-free-on-unbind.patch and it can be found in the queue-5.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From e13ee6cc4781edaf8c7321bee19217e3702ed481 Mon Sep 17 00:00:00 2001 From: Lukas Wunner <lukas@xxxxxxxxx> Date: Wed, 11 Nov 2020 20:07:30 +0100 Subject: spi: bcm2835aux: Fix use-after-free on unbind From: Lukas Wunner <lukas@xxxxxxxxx> commit e13ee6cc4781edaf8c7321bee19217e3702ed481 upstream. bcm2835aux_spi_remove() accesses the driver's private data after calling spi_unregister_master() even though that function releases the last reference on the spi_master 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: b9dd3f6d4172 ("spi: bcm2835aux: Fix controller unregister order") Signed-off-by: Lukas Wunner <lukas@xxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> # v4.4+: 123456789abc: spi: Introduce device-managed SPI controller allocation Cc: <stable@xxxxxxxxxxxxxxx> # v4.4+: b9dd3f6d4172: spi: bcm2835aux: Fix controller unregister order Cc: <stable@xxxxxxxxxxxxxxx> # v4.4+ Link: https://lore.kernel.org/r/b290b06357d0c0bdee9cecc539b840a90630f101.1605121038.git.lukas@xxxxxxxxx Signed-off-by: Mark Brown <broonie@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/spi/spi-bcm2835aux.c | 21 +++++++-------------- 1 file changed, 7 insertions(+), 14 deletions(-) --- a/drivers/spi/spi-bcm2835aux.c +++ b/drivers/spi/spi-bcm2835aux.c @@ -494,7 +494,7 @@ static int bcm2835aux_spi_probe(struct p unsigned long clk_hz; int err; - master = spi_alloc_master(&pdev->dev, sizeof(*bs)); + master = devm_spi_alloc_master(&pdev->dev, sizeof(*bs)); if (!master) return -ENOMEM; @@ -524,29 +524,24 @@ static int bcm2835aux_spi_probe(struct p /* the main area */ bs->regs = devm_platform_ioremap_resource(pdev, 0); - 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 PTR_ERR(bs->clk); } bs->irq = platform_get_irq(pdev, 0); - if (bs->irq <= 0) { - err = bs->irq ? bs->irq : -ENODEV; - goto out_master_put; - } + if (bs->irq <= 0) + return bs->irq ? bs->irq : -ENODEV; /* this also enables the HW block */ err = clk_prepare_enable(bs->clk); if (err) { dev_err(&pdev->dev, "could not prepare clock: %d\n", err); - goto out_master_put; + return err; } /* just checking if the clock returns a sane value */ @@ -581,8 +576,6 @@ static int bcm2835aux_spi_probe(struct p 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-5.9/spi-bcm2835aux-fix-use-after-free-on-unbind.patch queue-5.9/spi-lpspi-fix-use-after-free-on-unbind.patch queue-5.9/spi-npcm-fiu-don-t-leak-spi-master-in-probe-error-path.patch queue-5.9/spi-introduce-device-managed-spi-controller-allocation.patch