From 9840aa82c45aa474a0ef40ddc0cfbf59c2cff4c7 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Thu, 1 Dec 2011 14:12:55 -0500 Subject: Revert "udp: remove redundant variable" This reverts commit 81d54ec8479a2c695760da81f05b5a9fb2dbe40a. If we take the "try_again" goto, due to a checksum error, the 'len' has already been truncated. So we won't compute the same values as the original code did. Change-Id: I0503e45682377965571c4544385811765ef2e2bb Reported-by: paul bilke Signed-off-by: David S. Miller (cherry picked from commit 7c3b1de9c0ba32bd33ac15c62e8b8a0548641c6b) --- net/ipv4/udp.c | 15 ++++++++------- net/ipv6/udp.c | 15 ++++++++------- 2 files changed, 16 insertions(+), 14 deletions(-) diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 24c7f521537..05b0523096e 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1165,7 +1165,7 @@ int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, struct inet_sock *inet = inet_sk(sk); struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name; struct sk_buff *skb; - unsigned int ulen; + unsigned int ulen, copied; int peeked; int err; int is_udplite = IS_UDPLITE(sk); @@ -1187,9 +1187,10 @@ try_again: goto out; ulen = skb->len - sizeof(struct udphdr); - if (len > ulen) - len = ulen; - else if (len < ulen) + copied = len; + if (copied > ulen) + copied = ulen; + else if (copied < ulen) msg->msg_flags |= MSG_TRUNC; /* @@ -1198,14 +1199,14 @@ try_again: * coverage checksum (UDP-Lite), do it before the copy. */ - if (len < ulen || UDP_SKB_CB(skb)->partial_cov) { + if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) { if (udp_lib_checksum_complete(skb)) goto csum_copy_err; } if (skb_csum_unnecessary(skb)) err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), - msg->msg_iov, len); + msg->msg_iov, copied); else { err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), @@ -1234,7 +1235,7 @@ try_again: if (inet->cmsg_flags) ip_cmsg_recv(msg, skb); - err = len; + err = copied; if (flags & MSG_TRUNC) err = ulen; diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 62a3701e82d..2e3a22d8b3a 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -340,7 +340,7 @@ int udpv6_recvmsg(struct kiocb *iocb, struct sock *sk, struct ipv6_pinfo *np = inet6_sk(sk); struct inet_sock *inet = inet_sk(sk); struct sk_buff *skb; - unsigned int ulen; + unsigned int ulen, copied; int peeked; int err; int is_udplite = IS_UDPLITE(sk); @@ -363,9 +363,10 @@ try_again: goto out; ulen = skb->len - sizeof(struct udphdr); - if (len > ulen) - len = ulen; - else if (len < ulen) + copied = len; + if (copied > ulen) + copied = ulen; + else if (copied < ulen) msg->msg_flags |= MSG_TRUNC; is_udp4 = (skb->protocol == htons(ETH_P_IP)); @@ -376,14 +377,14 @@ try_again: * coverage checksum (UDP-Lite), do it before the copy. */ - if (len < ulen || UDP_SKB_CB(skb)->partial_cov) { + if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) { if (udp_lib_checksum_complete(skb)) goto csum_copy_err; } if (skb_csum_unnecessary(skb)) err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), - msg->msg_iov,len); + msg->msg_iov, copied ); else { err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov); if (err == -EINVAL) @@ -432,7 +433,7 @@ try_again: datagram_recv_ctl(sk, msg, skb); } - err = len; + err = copied; if (flags & MSG_TRUNC) err = ulen; -- cgit v1.2.3