At the start of ath9k_htc_rx_msg, we check to see if the skb pointer is valid, but what we don't do is check if it is large enough to contain a valid struct htc_frame_hdr. We should check for this and return if not, as the buffer is invalid in this case. Fixes a KMSAN-found uninit-value bug reported by syzbot at: https://syzkaller.appspot.com/bug?id=7dccb7d9ad4251df1c49f370607a49e1f09644ee Reported-by: syzbot+e4534e8c1c382508312c@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Phillip Potter <phil@xxxxxxxxxxxxxxxx> --- V2: * Free skb properly when this problem is detected, as pointed out by Florian Westphal. --- drivers/net/wireless/ath/ath9k/htc_hst.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/net/wireless/ath/ath9k/htc_hst.c b/drivers/net/wireless/ath/ath9k/htc_hst.c index 510e61e97dbc..1fe89b068ac4 100644 --- a/drivers/net/wireless/ath/ath9k/htc_hst.c +++ b/drivers/net/wireless/ath/ath9k/htc_hst.c @@ -406,6 +406,11 @@ void ath9k_htc_rx_msg(struct htc_target *htc_handle, if (!htc_handle || !skb) return; + if (!pskb_may_pull(skb, sizeof(struct htc_frame_hdr))) { + kfree_skb(skb); + return; + } + htc_hdr = (struct htc_frame_hdr *) skb->data; epid = htc_hdr->endpoint_id; -- 2.30.2
