From: [EMAIL PROTECTED] Date: Wed, 24 Jan 2007 19:54:51 -0800 > Hi, > > The following code: > [...] > > Causes the following oops: > ... > [ 66.355188] [<c0396c74>] error_code+0x7c/0x84 > [ 66.355192] [<f8adaf03>] packet_sendmsg+0x147/0x201 [af_packet] > [ 66.355199] [<c030e1c5>] sock_sendmsg+0xf9/0x116 > [ 66.355204] [<c030eb54>] sys_sendto+0xbf/0xe0 > [ 66.355208] [<c030f494>] sys_socketcall+0x1aa/0x277 > [ 66.355212] [<c01041ea>] sysenter_past_esp+0x5f/0x99 > [ 66.355216] ======================= > [ 66.355218] Code: Bad EIP value. > [ 66.355223] EIP: [<00000000>] 0x0 SS:ESP 0068:f6261d70 > > shaper_header() should check for shaper->dev not being NULL (ie. the > shaper was actually attached) as in the following patch. > This happens in mainline too (tested 2.6.19.2). > > Signed-off-by: Frederik Deweerdt <[EMAIL PROTECTED]> > Cc: "David S. Miller" <[EMAIL PROTECTED]> > Cc: Stephen Hemminger <[EMAIL PROTECTED]> > Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
Shaper is actually OK. None of these hardware header callbacks should be invoked if the device is down. Yet, this is what is accidently being allowed in the AF_PACKET socket layer. Shaper makes sure to fail ->open() if shaper->dev is NULL, in order to prevent this. But AF_PACKET does it's check of device state too late, after the dev->header() call. That's the bug. I'll fix it like this: diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 594c078..6dc01bd 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -359,6 +359,10 @@ static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock, if (dev == NULL) goto out_unlock; + err = -ENETDOWN; + if (!(dev->flags & IFF_UP)) + goto out_unlock; + /* * You may not queue a frame bigger than the mtu. This is the lowest level * raw protocol and you must do your own fragmentation at this level. @@ -407,10 +411,6 @@ static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock, if (err) goto out_free; - err = -ENETDOWN; - if (!(dev->flags & IFF_UP)) - goto out_free; - /* * Now send it */ @@ -738,6 +738,10 @@ static int packet_sendmsg(struct kiocb *iocb, struct socket *sock, if (sock->type == SOCK_RAW) reserve = dev->hard_header_len; + err = -ENETDOWN; + if (!(dev->flags & IFF_UP)) + goto out_unlock; + err = -EMSGSIZE; if (len > dev->mtu+reserve) goto out_unlock; @@ -770,10 +774,6 @@ static int packet_sendmsg(struct kiocb *iocb, struct socket *sock, skb->dev = dev; skb->priority = sk->sk_priority; - err = -ENETDOWN; - if (!(dev->flags & IFF_UP)) - goto out_free; - /* * Now send it */ - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html