[PATCH] fixp-arith: prevent division by zero in fixp_sin32_rad()

From: Roman Smirnov
Date: Tue Mar 12 2024 - 05:50:55 EST


The parameter twopi can have a zero value. It is necessary
to prevent division by zero.

Found by Linux Verification Center (linuxtesting.org) with Svace.

Signed-off-by: Roman Smirnov <r.smirnov@xxxxxx>
---
include/linux/fixp-arith.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/linux/fixp-arith.h b/include/linux/fixp-arith.h
index e485fb0c1201..434eee8bd9ef 100644
--- a/include/linux/fixp-arith.h
+++ b/include/linux/fixp-arith.h
@@ -118,8 +118,9 @@ static inline s32 fixp_sin32_rad(u32 radians, u32 twopi)

/*
* Avoid too large values for twopi, as we don't want overflows.
+ * Also prevent division by zero.
*/
- BUG_ON(twopi > 1 << 18);
+ BUG_ON(!twopi || twopi > 1 << 18);

degrees = (radians * 360) / twopi;
tmp = radians - (degrees * twopi) / 360;
--
2.34.1