Re: [syzbot] [input?] [usb?] UBSAN: shift-out-of-bounds in s32ton
From: Pei Xiao
Date: Wed Nov 13 2024 - 20:40:28 EST
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 81d6c734c8bc..ead1d338fa58 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -66,8 +66,11 @@ static s32 snto32(__u32 value, unsigned int n)
static u32 s32ton(__s32 value, unsigned int n)
{
- s32 a = value >> (n - 1);
+ s32 a;
+ if (n >= 32)
+ return value;
+ a = value >> (n - 1);
if (a && a != -1)
return value < 0 ? 1 << (n - 1) : (1 << (n - 1)) - 1;
return value & ((1 << n) - 1);