[3.8.y.z extended stable] Patch "ipv4: Fix runtime WARNING in rtmsg_ifa()" has been added to staging queue

[Kamal Mostafa]

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

    ipv4: Fix runtime WARNING in rtmsg_ifa()

to the linux-3.8.y-queue branch of the 3.8.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-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.21.

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

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 8dde451777fd2d122a27185010184f3921bb4d9a Mon Sep 17 00:00:00 2001
From: Geert Uytterhoeven <geert at linux-m68k.org>
Date: Wed, 5 Feb 2014 08:38:25 +0100
Subject: ipv4: Fix runtime WARNING in rtmsg_ifa()

[ Upstream commit 63b5f152eb4a5bb79b9caf7ec37b4201d12f6e66 ]

On m68k/ARAnyM:

WARNING: CPU: 0 PID: 407 at net/ipv4/devinet.c:1599 0x316a99()
Modules linked in:
CPU: 0 PID: 407 Comm: ifconfig Not tainted
3.13.0-atari-09263-g0c71d68014d1 #1378
Stack from 10c4fdf0:
        10c4fdf0 002ffabb 000243e8 00000000 008ced6c 00024416 00316a99 0000063f
        00316a99 00000009 00000000 002501b4 00316a99 0000063f c0a86117 00000080
        c0a86117 00ad0c90 00250a5a 00000014 00ad0c90 00000000 00000000 00000001
        00b02dd0 00356594 00000000 00356594 c0a86117 eff6c9e4 008ced6c 00000002
        008ced60 0024f9b4 00250b52 00ad0c90 00000000 00000000 00252390 00ad0c90
        eff6c9e4 0000004f 00000000 00000000 eff6c9e4 8000e25c eff6c9e4 80001020
Call Trace: [<000243e8>] warn_slowpath_common+0x52/0x6c
 [<00024416>] warn_slowpath_null+0x14/0x1a
 [<002501b4>] rtmsg_ifa+0xdc/0xf0
 [<00250a5a>] __inet_insert_ifa+0xd6/0x1c2
 [<0024f9b4>] inet_abc_len+0x0/0x42
 [<00250b52>] inet_insert_ifa+0xc/0x12
 [<00252390>] devinet_ioctl+0x2ae/0x5d6

Adding some debugging code reveals that net_fill_ifaddr() fails in

    put_cacheinfo(skb, ifa->ifa_cstamp, ifa->ifa_tstamp,
                              preferred, valid))

nla_put complains:

    lib/nlattr.c:454: skb_tailroom(skb) = 12, nla_total_size(attrlen) = 20

Apparently commit 5c766d642bcaffd0c2a5b354db2068515b3846cf ("ipv4:
introduce address lifetime") forgot to take into account the addition of
struct ifa_cacheinfo in inet_nlmsg_size(). Hence add it, like is already
done for ipv6.

Suggested-by: Cong Wang <cwang at twopensource.com>
Signed-off-by: Geert Uytterhoeven <geert at linux-m68k.org>
Signed-off-by: Cong Wang <cwang at twopensource.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 net/ipv4/devinet.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index a8e4f26..1b35f0d 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -1243,7 +1243,8 @@ static size_t inet_nlmsg_size(void)
 	       + nla_total_size(4) /* IFA_ADDRESS */
 	       + nla_total_size(4) /* IFA_LOCAL */
 	       + nla_total_size(4) /* IFA_BROADCAST */
-	       + nla_total_size(IFNAMSIZ); /* IFA_LABEL */
+	       + nla_total_size(IFNAMSIZ) /* IFA_LABEL */
+	       + nla_total_size(sizeof(struct ifa_cacheinfo)); /* IFA_CACHEINFO */
 }

 static int inet_fill_ifaddr(struct sk_buff *skb, struct in_ifaddr *ifa,
--
1.8.3.2