From 64c150339e7f6c5cbbe8c17a56ef2b3902612798 Mon Sep 17 00:00:00 2001 From: Maxim Korotkov Date: Thu, 17 Nov 2022 15:30:34 +0300 Subject: [PATCH] pinctrl: single: Fix potential division by zero 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 Reviewed-by: Tony Lindgren Link: https://lore.kernel.org/r/20221117123034.27383-1-korotkov.maxim.s@gmail.com Signed-off-by: Linus Walleij --- drivers/pinctrl/pinctrl-single.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/pinctrl/pinctrl-single.c b/drivers/pinctrl/pinctrl-single.c index 67bec7ea0f8b..414ee6bb8ac9 100644 --- a/drivers/pinctrl/pinctrl-single.c +++ b/drivers/pinctrl/pinctrl-single.c @@ -727,7 +727,7 @@ 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; } else {