ath9k_htc_rx_msg() assumes skb->data contains a full `struct htc_frame_hdr`, thus it needs a call to pskb_may_pull() to ensure there is enough data. This fixes a long-standing issue reported by KMSAN: BUG: KMSAN: uninit-value in ath9k_htc_rx_msg+0x544/0x980 drivers/net/wireless/ath/ath9k/htc_hst.c:417 ath9k_htc_rx_msg+0x544/0x980 drivers/net/wireless/ath/ath9k/htc_hst.c:417 ath9k_hif_usb_rx_stream drivers/net/wireless/ath/ath9k/hif_usb.c:653 [inline] ath9k_hif_usb_rx_cb+0x196a/0x1f10 drivers/net/wireless/ath/ath9k/hif_usb.c:686 __usb_hcd_giveback_urb+0x522/0x740 drivers/usb/core/hcd.c:1670 usb_hcd_giveback_urb+0x150/0x620 drivers/usb/core/hcd.c:1747 dummy_timer+0xd3f/0x4f20 drivers/usb/gadget/udc/dummy_hcd.c:1988 call_timer_fn+0x43/0x480 kernel/time/timer.c:1474 expire_timers+0x272/0x610 kernel/time/timer.c:1519 __run_timers+0x5bc/0x8c0 kernel/time/timer.c:1790 ... Uninit was created at: ... __alloc_skb+0x34a/0xd70 net/core/skbuff.c:426 __netdev_alloc_skb+0x126/0x780 net/core/skbuff.c:494 __dev_alloc_skb include/linux/skbuff.h:3264 [inline] ath9k_hif_usb_rx_stream drivers/net/wireless/ath/ath9k/hif_usb.c:635 [inline] ath9k_hif_usb_rx_cb+0xe7b/0x1f10 drivers/net/wireless/ath/ath9k/hif_usb.c:686 __usb_hcd_giveback_urb+0x522/0x740 drivers/usb/core/hcd.c:1670 ... Reported-by: syzbot+2ca247c2d60c7023de7f@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Phillip Potter <phil@xxxxxxxxxxxxxxxx> Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx> --- drivers/net/wireless/ath/ath9k/htc_hst.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/ath/ath9k/htc_hst.c b/drivers/net/wireless/ath/ath9k/htc_hst.c index 994ec48b2f669..83a1d2fba2218 100644 --- a/drivers/net/wireless/ath/ath9k/htc_hst.c +++ b/drivers/net/wireless/ath/ath9k/htc_hst.c @@ -408,7 +408,8 @@ void ath9k_htc_rx_msg(struct htc_target *htc_handle, struct htc_endpoint *endpoint; __be16 *msg_id; - if (!htc_handle || !skb) + if (!htc_handle || !skb || + !pskb_may_pull(skb, sizeof(struct htc_frame_hdr))) return; htc_hdr = (struct htc_frame_hdr *) skb->data; -- 2.37.2.672.g94769d06f0-goog
