From fba360a047d5eeeb9d4b7c3a9b1c8308980ce9a6 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Tue, 15 Aug 2023 21:28:01 +0200 Subject: [PATCH] wifi: mac80211_hwsim: drop short frames 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@syzkaller.appspotmail.com Reviewed-by: Jeff Johnson Signed-off-by: Johannes Berg --- drivers/net/wireless/virtual/mac80211_hwsim.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/net/wireless/virtual/mac80211_hwsim.c b/drivers/net/wireless/virtual/mac80211_hwsim.c index f446fd0..dd516ce 100644 --- a/drivers/net/wireless/virtual/mac80211_hwsim.c +++ b/drivers/net/wireless/virtual/mac80211_hwsim.c @@ -5626,14 +5626,15 @@ 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); -- 2.7.4