This is a note to let you know that I've just added the patch titled spi: Fix documentation of spi_alloc_master() to the 4.2-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-fix-documentation-of-spi_alloc_master.patch and it can be found in the queue-4.2 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From a394d635193b641f2c86ead5ada5b115d57c51f8 Mon Sep 17 00:00:00 2001 From: Guenter Roeck <linux@xxxxxxxxxxxx> Date: Sun, 6 Sep 2015 01:46:54 +0300 Subject: spi: Fix documentation of spi_alloc_master() From: Guenter Roeck <linux@xxxxxxxxxxxx> commit a394d635193b641f2c86ead5ada5b115d57c51f8 upstream. Actually, spi_master_put() after spi_alloc_master() must _not_ be followed by kfree(). The memory is already freed with the call to spi_master_put() through spi_master_class, which registers a release function. Calling both spi_master_put() and kfree() results in often nasty (and delayed) crashes elsewhere in the kernel, often in the networking stack. This reverts commit eb4af0f5349235df2e4a5057a72fc8962d00308a. Link to patch and concerns: https://lkml.org/lkml/2012/9/3/269 or http://lkml.iu.edu/hypermail/linux/kernel/1209.0/00790.html Alexey Klimov: This revert becomes valid after 94c69f765f1b4a658d96905ec59928e3e3e07e6a when spi-imx.c has been fixed and there is no need to call kfree() so comment for spi_alloc_master() should be fixed. Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx> Signed-off-by: Alexey Klimov <alexey.klimov@xxxxxxxxxx> Signed-off-by: Mark Brown <broonie@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/spi/spi.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -1437,8 +1437,7 @@ static struct class spi_master_class = { * * The caller is responsible for assigning the bus number and initializing * the master's methods before calling spi_register_master(); and (after errors - * adding the device) calling spi_master_put() and kfree() to prevent a memory - * leak. + * adding the device) calling spi_master_put() to prevent a memory leak. */ struct spi_master *spi_alloc_master(struct device *dev, unsigned size) { Patches currently in stable-queue which might be from linux@xxxxxxxxxxxx are queue-4.2/spi-fix-documentation-of-spi_alloc_master.patch queue-4.2/lib-iommu-common.c-do-not-try-to-deref-a-null-iommu-lazy_flush-pointer-when-n-pool-hint.patch queue-4.2/hwmon-nct6775-swap-step_up_time-and-step_down_time-registers-for-most-chips.patch queue-4.2/watchdog-sunxi-fix-activation-of-system-reset.patch queue-4.2/watchdog-imgpdc-unregister-restart-handler-on-remove.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html