From: Maxim Korotkov korotkov.maxim.s@gmail.com
[ 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@gmail.com Reviewed-by: Tony Lindgren tony@atomide.com Link: https://lore.kernel.org/r/20221117123034.27383-1-korotkov.maxim.s@gmail.com Signed-off-by: Linus Walleij linus.walleij@linaro.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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;