s32ton always be 0 when n>=32,add check n. Reported-by: syzbot+3fa2af55f15bd21cada9@xxxxxxxxxxxxxxxxxxxxxxxxx Closes: https://syzkaller.appspot.com/bug?extid=3fa2af55f15bd21cada9 Fixes: c653ffc28340 ("HID: stop exporting hid_snto32()") Signed-off-by: Pei Xiao <xiaopei01@xxxxxxxxxx> --- drivers/hid/hid-core.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) 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); -- 2.34.1
