From dbabad0c9c026dea3ba803cbd9d768cdffc68e32 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Thu, 8 May 2008 01:43:59 +0200 Subject: [PATCH] zd1211rw: fix potential use-after-free bug zd_mac_tx_to_dev() could potentially free the skb, or hand it off to mac80211 which might free it. Hence, this code needs to get the usb pointer out of skb->cb before handing it off to that function. Signed-off-by: Johannes Berg Signed-off-by: John W. Linville --- drivers/net/wireless/zd1211rw/zd_usb.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/zd1211rw/zd_usb.c b/drivers/net/wireless/zd1211rw/zd_usb.c index 5316074f39f0..12e24f04dddf 100644 --- a/drivers/net/wireless/zd1211rw/zd_usb.c +++ b/drivers/net/wireless/zd1211rw/zd_usb.c @@ -889,9 +889,13 @@ static void tx_urb_complete(struct urb *urb) } free_urb: skb = (struct sk_buff *)urb->context; - zd_mac_tx_to_dev(skb, urb->status); + /* + * grab 'usb' pointer before handing off the skb (since + * it might be freed by zd_mac_tx_to_dev or mac80211) + */ cb = (struct zd_tx_skb_control_block *)skb->cb; usb = &zd_hw_mac(cb->hw)->chip.usb; + zd_mac_tx_to_dev(skb, urb->status); free_tx_urb(usb, urb); tx_dec_submitted_urbs(usb); return; -- 2.39.5