[ 34/46] tipc: set sk_err correctly when connection fails

From: Greg Kroah-Hartman
Date: Thu Sep 12 2013 - 14:04:34 EST


3.10-stable review patch. If anyone has any objections, please let me know.

------------------

From: Erik Hugne <erik.hugne@xxxxxxxxxxxx>

[ Upstream commit 2c8d85182348021fc0a1bed193a4be4161dc8364 ]

Should a connect fail, if the publication/server is unavailable or
due to some other error, a positive value will be returned and errno
is never set. If the application code checks for an explicit zero
return from connect (success) or a negative return (failure), it
will not catch the error and subsequent send() calls will fail as
shown from the strace snippet below.

socket(0x1e /* PF_??? */, SOCK_SEQPACKET, 0) = 3
connect(3, {sa_family=0x1e /* AF_??? */, sa_data="\2\1\322\4\0\0\322\4\0\0\0\0\0\0"}, 16) = 111
sendto(3, "test", 4, 0, NULL, 0) = -1 EPIPE (Broken pipe)

The reason for this behaviour is that TIPC wrongly inverts error
codes set in sk_err.

Signed-off-by: Erik Hugne <erik.hugne@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/tipc/socket.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -1179,7 +1179,7 @@ static u32 filter_connect(struct tipc_so
/* Accept only ACK or NACK message */
if (unlikely(msg_errcode(msg))) {
sock->state = SS_DISCONNECTING;
- sk->sk_err = -ECONNREFUSED;
+ sk->sk_err = ECONNREFUSED;
retval = TIPC_OK;
break;
}
@@ -1190,7 +1190,7 @@ static u32 filter_connect(struct tipc_so
res = auto_connect(sock, msg);
if (res) {
sock->state = SS_DISCONNECTING;
- sk->sk_err = res;
+ sk->sk_err = -res;
retval = TIPC_OK;
break;
}


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