| Message ID | 20230424183348.111355-1-pchelkin@ispras.ru |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] wifi: ath9k: avoid referencing uninit memory in ath9k_wmi_ctrl_rx | expand |
diff --git a/drivers/net/wireless/ath/ath9k/wmi.c b/drivers/net/wireless/ath/ath9k/wmi.c index 19345b8f7bfd..d652c647d56b 100644 --- a/drivers/net/wireless/ath/ath9k/wmi.c +++ b/drivers/net/wireless/ath/ath9k/wmi.c @@ -221,6 +221,10 @@ static void ath9k_wmi_ctrl_rx(void *priv, struct sk_buff *skb, if (unlikely(wmi->stopped)) goto free_skb; + /* Validate the obtained SKB. */ + if (unlikely(skb->len < sizeof(struct wmi_cmd_hdr))) + goto free_skb; + hdr = (struct wmi_cmd_hdr *) skb->data; cmd_id = be16_to_cpu(hdr->command_id);
For the reasons also described in commit b383e8abed41 ("wifi: ath9k: avoid uninit memory read in ath9k_htc_rx_msg()"), ath9k_htc_rx_msg() should validate pkt_len before accessing the SKB. For example, the obtained SKB may have been badly constructed with pkt_len = 8. In this case, the SKB can only contain a valid htc_frame_hdr but after being processed in ath9k_htc_rx_msg() and passed to ath9k_wmi_ctrl_rx() endpoint RX handler, it is expected to have a WMI command header which should be located inside its data payload. Implement sanity checking inside ath9k_wmi_ctrl_rx(). Otherwise, uninit memory can be referenced. Tested on Qualcomm Atheros Communications AR9271 802.11n . Found by Linux Verification Center (linuxtesting.org) with Syzkaller. Fixes: fb9987d0f748 ("ath9k_htc: Support for AR9271 chipset.") Reported-and-tested-by: syzbot+f2cb6e0ffdb961921e4d@syzkaller.appspotmail.com Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru> --- v2: remove incorrect checks and rephrase commit info drivers/net/wireless/ath/ath9k/wmi.c | 4 ++++ 1 file changed, 4 insertions(+)