From 76b98d8f55138fbad1c46736b9c5a603ad344864 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 stable inclusion from stable-v5.10.158 commit 302edce1dd426f7e2abfed35563dec8d5aed0667 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I7NTXH Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=302edce1dd426f7e2abfed35563dec8d5aed0667 -------------------------------- [ 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 Reviewed-by: Tony Lindgren Link: https://lore.kernel.org/r/20221117123034.27383-1-korotkov.maxim.s@gmail.com Signed-off-by: Linus Walleij Signed-off-by: Sasha Levin Signed-off-by: sanglipeng --- 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 17aa0d542d92..d139cd9e6d13 100644 --- a/drivers/pinctrl/pinctrl-single.c +++ b/drivers/pinctrl/pinctrl-single.c @@ -726,7 +726,7 @@ 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; -- GitLab