From: Jiri Pirko <jpirko@redhat.com>
Date: Mon, 26 Apr 2010 15:47:54 -0400
Subject: [net] sctp: file must be valid before setting timeout
Message-id: <20100426154754.GL2941@psychotron.lab.eng.brq.redhat.com>
Patchwork-id: 24624
O-Subject: [RHEL5.6 patch] BZ578261 net: SCTP: Check to make sure file is valid
	before setting timeout
Bugzilla: 578261
RH-Acked-by: Neil Horman <nhorman@redhat.com>
RH-Acked-by: John Feeney <jfeeney@redhat.com>
RH-Acked-by: Dean Nelson <dnelson@redhat.com>

BZ578261
https://bugzilla.redhat.com/show_bug.cgi?id=578261

Description:
In-kernel sockets created with sock_create_kern don't usually
have a file and file descriptor allocated to them.  As a result,
when SCTP tries to check the non-blocking flag, we Oops when
dereferencing a NULL file pointer.

Upstream:
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff_plain;h=f50f95cab735ebe2993e8d1549f0615bad05f3f2

Brew:
https://brewweb.devel.redhat.com/taskinfo?taskID=2401567

Tested on x86_64. Works as expected.

Jirka

Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Signed-off-by: Jarod Wilson <jarod@redhat.com>

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index a60f7d8..32d4750 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -1002,6 +1002,7 @@ static int __sctp_connect(struct sock* sk,
 	int walk_size = 0;
 	struct sockaddr *sa_addr;
 	void *addr_buf;
+	unsigned int f_flags = 0;
 
 	sp = sctp_sk(sk);
 	ep = sp->ep;
@@ -1123,7 +1124,14 @@ static int __sctp_connect(struct sock* sk,
 	af->to_sk_daddr(&to, sk);
 	sk->sk_err = 0;
 
-	timeo = sock_sndtimeo(sk, sk->sk_socket->file->f_flags & O_NONBLOCK);
+	/* in-kernel sockets don't generally have a file allocated to them
+	 * if all they do is call sock_create_kern().
+	 */
+	if (sk->sk_socket->file)
+		f_flags = sk->sk_socket->file->f_flags;
+
+	timeo = sock_sndtimeo(sk, f_flags & O_NONBLOCK);
+
 	err = sctp_wait_for_connect(asoc, &timeo);
 
 	/* Don't free association on exit. */