Re: [Linux-kernel-mentees][PATCH v2] nl80211: Fix undefined behavior in bit shift

From: Shuah Khan
Date: Wed Jun 26 2019 - 23:34:27 EST


On 6/26/19 9:25 PM, Jiunn Chang wrote:
Shifting signed 32-bit value by 31 bits is undefined. Changing most
significant bit to unsigned.

Changes included in v2:
- use subsystem specific subject lines
- CC required mailing lists

Signed-off-by: Jiunn Chang <c0d1n61at3@xxxxxxxxx>
---

Move version change lines here. They don't belong in the commit log.

include/uapi/linux/nl80211.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index 6f09d1500960..fa7ebbc6ff27 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -5314,7 +5314,7 @@ enum nl80211_feature_flags {
NL80211_FEATURE_TDLS_CHANNEL_SWITCH = 1 << 28,
NL80211_FEATURE_SCAN_RANDOM_MAC_ADDR = 1 << 29,
NL80211_FEATURE_SCHED_SCAN_RANDOM_MAC_ADDR = 1 << 30,
- NL80211_FEATURE_ND_RANDOM_MAC_ADDR = 1 << 31,
+ NL80211_FEATURE_ND_RANDOM_MAC_ADDR = 1U << 31,
};
/**


thanks,
-- Shuah