From: Toke Høiland-Jørgensen <toke@xxxxxxxxxx> Syzbot points out that skb_trim() has a sanity check on the existing length of the skb, which can be uninitialised in some error paths. The intent here is clearly just to reset the length to zero before resubmitting, so switch to calling __skb_set_length(skb, 0) directly. In addition, __skb_set_length() already contains a call to skb_reset_tail_pointer(), so remove the redundant call. The syzbot report came from ath9k_hif_usb_reg_in_cb(), but there's a similar usage of skb_trim() in ath9k_hif_usb_rx_cb(), change both while we're at it. Reported-by: syzbot+98afa303be379af6cdb2@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx> --- drivers/net/wireless/ath/ath9k/hif_usb.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/drivers/net/wireless/ath/ath9k/hif_usb.c b/drivers/net/wireless/ath/ath9k/hif_usb.c index 0c7841f95228..a3733c9b484e 100644 --- a/drivers/net/wireless/ath/ath9k/hif_usb.c +++ b/drivers/net/wireless/ath/ath9k/hif_usb.c @@ -716,8 +716,7 @@ static void ath9k_hif_usb_rx_cb(struct urb *urb) } resubmit: - skb_reset_tail_pointer(skb); - skb_trim(skb, 0); + __skb_set_length(skb, 0); usb_anchor_urb(urb, &hif_dev->rx_submitted); ret = usb_submit_urb(urb, GFP_ATOMIC); @@ -754,8 +753,7 @@ static void ath9k_hif_usb_reg_in_cb(struct urb *urb) case -ESHUTDOWN: goto free_skb; default: - skb_reset_tail_pointer(skb); - skb_trim(skb, 0); + __skb_set_length(skb, 0); goto resubmit; } -- 2.46.0
