syzbot, using KMSAN, has reported an uninit-value access in hwsim_cloned_frame_received_nl(). This is happening because frame_data_len is 0. The code doesn't detect this case and blindly tries to read the frame's header. Fix this by bailing out in case frame_data_len is 0. Reported-by: syzbot+b2645b5bf1512b81fa22@xxxxxxxxxxxxxxxxxxxxxxxxx Tested-by: syzbot+b2645b5bf1512b81fa22@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Anirudh Rayabharam <mail@xxxxxxxxxxxxx> --- drivers/net/wireless/mac80211_hwsim.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c index 51ce767eaf88..ccfe40313109 100644 --- a/drivers/net/wireless/mac80211_hwsim.c +++ b/drivers/net/wireless/mac80211_hwsim.c @@ -3649,7 +3649,7 @@ static int hwsim_cloned_frame_received_nl(struct sk_buff *skb_2, if (skb == NULL) goto err; - if (frame_data_len > IEEE80211_MAX_DATA_LEN) + if (frame_data_len == 0 || frame_data_len > IEEE80211_MAX_DATA_LEN) goto err; /* Copy the data */ -- 2.26.2
