[3.11.y.z extended stable] Patch "inet: fix possible seqlock deadlocks" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    inet: fix possible seqlock deadlocks

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 46e6799a5eb34c3529f9c948e54f9e47fe68574b Mon Sep 17 00:00:00 2001
From: Eric Dumazet <edumazet at google.com>
Date: Thu, 28 Nov 2013 09:51:22 -0800
Subject: inet: fix possible seqlock deadlocks

commit f1d8cba61c3c4b1eb88e507249c4cb8d635d9a76 upstream.

In commit c9e9042994d3 ("ipv4: fix possible seqlock deadlock") I left
another places where IP_INC_STATS_BH() were improperly used.

udp_sendmsg(), ping_v4_sendmsg() and tcp_v4_connect() are called from
process context, not from softirq context.

This was detected by lockdep seqlock support.

Reported-by: jongman heo <jongman.heo at samsung.com>
Fixes: 584bdf8cbdf6 ("[IPV4]: Fix "ipOutNoRoutes" counter error for TCP and UDP")
Fixes: c319b4d76b9e ("net: ipv4: add IPPROTO_ICMP socket kind")
Signed-off-by: Eric Dumazet <edumazet at google.com>
Cc: Hannes Frederic Sowa <hannes at stressinduktion.org>
Acked-by: Hannes Frederic Sowa <hannes at stressinduktion.org>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 net/ipv4/ping.c     | 2 +-
 net/ipv4/tcp_ipv4.c | 2 +-
 net/ipv4/udp.c      | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c
index 09ee970..d7886b2 100644
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -769,7 +769,7 @@ int ping_v4_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 		err = PTR_ERR(rt);
 		rt = NULL;
 		if (err == -ENETUNREACH)
-			IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
+			IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
 		goto out;
 	}

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index b299da5..0f20350 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -177,7 +177,7 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 	if (IS_ERR(rt)) {
 		err = PTR_ERR(rt);
 		if (err == -ENETUNREACH)
-			IP_INC_STATS_BH(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
+			IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
 		return err;
 	}

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index a1787101d..b30deb9 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -972,7 +972,7 @@ int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 			err = PTR_ERR(rt);
 			rt = NULL;
 			if (err == -ENETUNREACH)
-				IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
+				IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
 			goto out;
 		}

--
1.8.3.2