This is a note to let you know that I've just added the patch titled pinctrl: single: Fix potential division by zero to the 5.4-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: pinctrl-single-fix-potential-division-by-zero.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 0697136c4e5536aa883f548f52e4cd6de53a3315 Author: Maxim Korotkov <korotkov.maxim.s@xxxxxxxxx> Date: Thu Nov 17 15:30:34 2022 +0300 pinctrl: single: Fix potential division by zero [ Upstream commit 64c150339e7f6c5cbbe8c17a56ef2b3902612798 ] There is a possibility of dividing by zero due to the pcs->bits_per_pin if pcs->fmask() also has a value of zero and called fls from asm-generic/bitops/builtin-fls.h or arch/x86/include/asm/bitops.h. The function pcs_probe() has the branch that assigned to fmask 0 before pcs_allocate_pin_table() was called Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: 4e7e8017a80e ("pinctrl: pinctrl-single: enhance to configure multiple pins of different modules") Signed-off-by: Maxim Korotkov <korotkov.maxim.s@xxxxxxxxx> Reviewed-by: Tony Lindgren <tony@xxxxxxxxxxx> Link: https://lore.kernel.org/r/20221117123034.27383-1-korotkov.maxim.s@xxxxxxxxx Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/pinctrl/pinctrl-single.c b/drivers/pinctrl/pinctrl-single.c index fb1c8965cb99..20c89023d312 100644 --- a/drivers/pinctrl/pinctrl-single.c +++ b/drivers/pinctrl/pinctrl-single.c @@ -703,7 +703,7 @@ static int pcs_allocate_pin_table(struct pcs_device *pcs) mux_bytes = pcs->width / BITS_PER_BYTE; - if (pcs->bits_per_mux) { + if (pcs->bits_per_mux && pcs->fmask) { pcs->bits_per_pin = fls(pcs->fmask); nr_pins = (pcs->size * BITS_PER_BYTE) / pcs->bits_per_pin; num_pins_in_register = pcs->width / pcs->bits_per_pin;