| Message ID | 1383002903-8746-1-git-send-email-Larry.Finger@lwfinger.net (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On Mon, 2013-10-28 at 18:28 -0500, Larry Finger wrote: > From: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk> > > All of the rtlwifi drivers have an error in the routine that tests if > the received data is "special". The 16-bit quantity is big-endian, but > was being extracted in native CPU mode. One of the effects of this bug > is to inhibit association under some conditions. > > A statement that would have made the code correct had been changed to > a comment. Rather than just reinstating that code, the fix here passes > sparse tests. > > Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net> > Cc: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk> > Cc: Stable <stable@vger.kernel.org> [2.6.38+] > --- > drivers/net/wireless/rtlwifi/base.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > diff --git a/drivers/net/wireless/rtlwifi/base.c b/drivers/net/wireless/rtlwifi/base.c > index 9a78e3d..1efde7f 100644 > --- a/drivers/net/wireless/rtlwifi/base.c > +++ b/drivers/net/wireless/rtlwifi/base.c > @@ -1077,8 +1077,8 @@ u8 rtl_is_special_data(struct ieee80211_hw *hw, struct sk_buff *skb, u8 is_tx) > > ip = (struct iphdr *)((u8 *) skb->data + mac_hdr_len + > SNAP_SIZE + PROTOC_TYPE_SIZE); > - ether_type = *(u16 *) ((u8 *) skb->data + mac_hdr_len + SNAP_SIZE); > - /* ether_type = ntohs(ether_type); */ > + ether_type = be16_to_cpu(*(__be16 *)((u8 *)skb->data + mac_hdr_len + > + SNAP_SIZE)); > > if (ETH_P_IP == ether_type) { > if (IPPROTO_UDP == ip->protocol) { This crazy function also says that *all* IPv6 frames are special, which apparently means that on TX they should get sent at the lowest possible bit rate. So I think this is going to cause a regression for IPv6 throughput unless you remove that case. The DHCP case is also not validating IP and UDP header lengths against the packet length, though this may be harmless in practice. Ben.
Ben Hutchings <bhutchings@solarflare.com> writes: >> @@ -1077,8 +1077,8 @@ u8 rtl_is_special_data(struct ieee80211_hw *hw, struct sk_buff *skb, u8 is_tx) >> >> ip = (struct iphdr *)((u8 *) skb->data + mac_hdr_len + >> SNAP_SIZE + PROTOC_TYPE_SIZE); >> - ether_type = *(u16 *) ((u8 *) skb->data + mac_hdr_len + SNAP_SIZE); >> - /* ether_type = ntohs(ether_type); */ >> + ether_type = be16_to_cpu(*(__be16 *)((u8 *)skb->data + mac_hdr_len + >> + SNAP_SIZE)); >> >> if (ETH_P_IP == ether_type) { >> if (IPPROTO_UDP == ip->protocol) { > > This crazy function also says that *all* IPv6 frames are special, which > apparently means that on TX they should get sent at the lowest possible > bit rate. So I think this is going to cause a regression for IPv6 > throughput unless you remove that case. > > The DHCP case is also not validating IP and UDP header lengths against > the packet length, though this may be harmless in practice. It's not validating the upper 8 bits of the port numbers either, so it will hit random UDP traffic in addition to DHCP. But it was good to see this function now. I was wondering how to support some buggy 3G modem firmware without ugly hacks. Seems there will always be worse hacks in drivers/net, no matter what I do :-) Bjørn -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 10/29/2013 09:27 AM, Bjørn Mork wrote: > > It's not validating the upper 8 bits of the port numbers either, so it > will hit random UDP traffic in addition to DHCP. > > But it was good to see this function now. I was wondering how to support > some buggy 3G modem firmware without ugly hacks. Seems there will always > be worse hacks in drivers/net, no matter what I do :-) I'm happy that Realtek and I could make your day. The next version is checking the full 16-bit port numbers. Thanks, Larry -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/net/wireless/rtlwifi/base.c b/drivers/net/wireless/rtlwifi/base.c index 9a78e3d..1efde7f 100644 --- a/drivers/net/wireless/rtlwifi/base.c +++ b/drivers/net/wireless/rtlwifi/base.c @@ -1077,8 +1077,8 @@ u8 rtl_is_special_data(struct ieee80211_hw *hw, struct sk_buff *skb, u8 is_tx) ip = (struct iphdr *)((u8 *) skb->data + mac_hdr_len + SNAP_SIZE + PROTOC_TYPE_SIZE); - ether_type = *(u16 *) ((u8 *) skb->data + mac_hdr_len + SNAP_SIZE); - /* ether_type = ntohs(ether_type); */ + ether_type = be16_to_cpu(*(__be16 *)((u8 *)skb->data + mac_hdr_len + + SNAP_SIZE)); if (ETH_P_IP == ether_type) { if (IPPROTO_UDP == ip->protocol) {