Commit 90b7e112 authored by Adam Langley's avatar Adam Langley Committed by David S. Miller
Browse files

tcp: MD5: Fix MD5 signatures on certain ACK packets 



I noticed, looking at tcpdumps, that timewait ACKs were getting sent
with an incorrect MD5 signature when signatures were enabled.

I broke this in 49a72dfb ("tcp: Fix
MD5 signatures for non-linear skbs"). I didn't take into account that
the skb passed to tcp_*_send_ack was the inbound packet, thus the
source and dest addresses need to be swapped when calculating the MD5
pseudoheader.

Signed-off-by: default avatarAdam Langley <agl@imperialviolet.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 77e2f14f

net/ipv4/tcp_ipv4.c

+2 −2
Original line number Diff line number Diff line
@@ -655,8 +655,8 @@ static void tcp_v4_send_ack(struct sk_buff *skb, u32 seq, u32 ack, 
		rep.th.doff = arg.iov[0].iov_len/4;



		tcp_v4_md5_hash_hdr((__u8 *) &rep.opt[offset],

				    key, ip_hdr(skb)->daddr,

				    ip_hdr(skb)->saddr, &rep.th);

				    key, ip_hdr(skb)->saddr,

				    ip_hdr(skb)->daddr, &rep.th);

	}

#endif

	arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr,

net/ipv6/tcp_ipv6.c

+2 −2
Original line number Diff line number Diff line
@@ -1094,8 +1094,8 @@ static void tcp_v6_send_ack(struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 
		*topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |

				(TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);

		tcp_v6_md5_hash_hdr((__u8 *)topt, key,

				    &ipv6_hdr(skb)->daddr,

				    &ipv6_hdr(skb)->saddr, t1);

				    &ipv6_hdr(skb)->saddr,

				    &ipv6_hdr(skb)->daddr, t1);

	}

#endif

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