From 14da0230d8ad4f9c599703580b5c52de9b68851a Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Fri, 6 Jul 2018 11:39:21 +0300 Subject: [PATCH] Staging: Gasket: shift wrapping bug in gasket_read_modify_write_64() This function only has one caller so mask_width is 1 and mask_shift is 32. Shifting an int by 32 bits is undefined, but I guess on GCC it wraps to 0x1? Anyway it's supposed to be 0x100000000. Fixes: 9a69f5087ccc ("drivers/staging: Gasket driver framework + Apex driver") Signed-off-by: Dan Carpenter Signed-off-by: Greg Kroah-Hartman --- gasket_core.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/gasket_core.h b/gasket_core.h index 203b9a3..5d6535a 100644 --- a/gasket_core.h +++ b/gasket_core.h @@ -683,7 +683,7 @@ static inline void gasket_read_modify_write_64( u64 mask, tmp; tmp = gasket_dev_read_64(dev, bar, location); - mask = ((1 << mask_width) - 1) << mask_shift; + mask = ((1ULL << mask_width) - 1) << mask_shift; tmp = (tmp & ~mask) | (value << mask_shift); gasket_dev_write_64(dev, tmp, bar, location); }