From: Johannes Berg <johannes.berg@xxxxxxxxx> [ Upstream commit fba360a047d5eeeb9d4b7c3a9b1c8308980ce9a6 ] While technically some control frames like ACK are shorter and end after Address 1, such frames shouldn't be forwarded through wmediumd or similar userspace, so require the full 3-address header to avoid accessing invalid memory if shorter frames are passed in. Reported-by: syzbot+b2645b5bf1512b81fa22@xxxxxxxxxxxxxxxxxxxxxxxxx Reviewed-by: Jeff Johnson <quic_jjohnson@xxxxxxxxxxx> Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/net/wireless/mac80211_hwsim.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c index f80b1d57d6c38..a21739b2f44e6 100644 --- a/drivers/net/wireless/mac80211_hwsim.c +++ b/drivers/net/wireless/mac80211_hwsim.c @@ -3367,14 +3367,15 @@ static int hwsim_cloned_frame_received_nl(struct sk_buff *skb_2, frame_data_len = nla_len(info->attrs[HWSIM_ATTR_FRAME]); frame_data = (void *)nla_data(info->attrs[HWSIM_ATTR_FRAME]); + if (frame_data_len < sizeof(struct ieee80211_hdr_3addr) || + frame_data_len > IEEE80211_MAX_DATA_LEN) + goto err; + /* Allocate new skb here */ skb = alloc_skb(frame_data_len, GFP_KERNEL); if (skb == NULL) goto err; - if (frame_data_len > IEEE80211_MAX_DATA_LEN) - goto err; - /* Copy the data */ skb_put_data(skb, frame_data, frame_data_len); -- 2.40.1
