linux.git/net/ipv4, branch v2.6.38

Merge branch 'master' of /home/davem/src/GIT/linux-2.6/

2011-03-10T22:00:44+00:00

net: don't allow CAP_NET_ADMIN to load non-netdev kernel modules

2011-03-09T23:25:19+00:00

Since a8f80e8ff94ecba629542d9b4b5f5a8ee3eb565c any process with
CAP_NET_ADMIN may load any module from /lib/modules/.  This doesn't mean
that CAP_NET_ADMIN is a superset of CAP_SYS_MODULE as modules are
limited to /lib/modules/**.  However, CAP_NET_ADMIN capability shouldn't
allow anybody load any module not related to networking.

This patch restricts an ability of autoloading modules to netdev modules
with explicit aliases.  This fixes CVE-2011-1019.

Arnd Bergmann suggested to leave untouched the old pre-v2.6.32 behavior
of loading netdev modules by name (without any prefix) for processes
with CAP_SYS_MODULE to maintain the compatibility with network scripts
that use autoloading netdev modules by aliases like "eth0", "wlan0".

Currently there are only three users of the feature in the upstream
kernel: ipip, ip_gre and sit.

    root@albatros:~# capsh --drop=$(seq -s, 0 11),$(seq -s, 13 34) --
    root@albatros:~# grep Cap /proc/$$/status
    CapInh:	0000000000000000
    CapPrm:	fffffff800001000
    CapEff:	fffffff800001000
    CapBnd:	fffffff800001000
    root@albatros:~# modprobe xfs
    FATAL: Error inserting xfs
    (/lib/modules/2.6.38-rc6-00001-g2bf4ca3/kernel/fs/xfs/xfs.ko): Operation not permitted
    root@albatros:~# lsmod | grep xfs
    root@albatros:~# ifconfig xfs
    xfs: error fetching interface information: Device not found
    root@albatros:~# lsmod | grep xfs
    root@albatros:~# lsmod | grep sit
    root@albatros:~# ifconfig sit
    sit: error fetching interface information: Device not found
    root@albatros:~# lsmod | grep sit
    root@albatros:~# ifconfig sit0
    sit0      Link encap:IPv6-in-IPv4
	      NOARP  MTU:1480  Metric:1

    root@albatros:~# lsmod | grep sit
    sit                    10457  0
    tunnel4                 2957  1 sit

For CAP_SYS_MODULE module loading is still relaxed:

    root@albatros:~# grep Cap /proc/$$/status
    CapInh:	0000000000000000
    CapPrm:	ffffffffffffffff
    CapEff:	ffffffffffffffff
    CapBnd:	ffffffffffffffff
    root@albatros:~# ifconfig xfs
    xfs: error fetching interface information: Device not found
    root@albatros:~# lsmod | grep xfs
    xfs                   745319  0

Reference: https://lkml.org/lkml/2011/2/24/203

Signed-off-by: Vasiliy Kulikov 
Signed-off-by: Michael Tokarev 
Acked-by: David S. Miller 
Acked-by: Kees Cook 
Signed-off-by: James Morris

ipv4: Fix erroneous uses of ifa_address.

2011-03-09T21:27:16+00:00

In usual cases ifa_address == ifa_local, but in the case where
SIOCSIFDSTADDR sets the destination address on a point-to-point
link, ifa_address gets set to that destination address.

Therefore we should use ifa_local when we want the local interface
address.

There were two cases where the selection was done incorrectly:

1) When devinet_ioctl() does matching, it checks ifa_address even
   though gifconf correct reported ifa_local to the user

2) IN_DEV_ARP_NOTIFY handling sends a gratuitous ARP using
   ifa_address instead of ifa_local.

Reported-by: Julian Anastasov 
Signed-off-by: David S. Miller

tcp: undo_retrans counter fixes

2011-02-21T19:31:18+00:00

Fix a bug that undo_retrans is incorrectly decremented when undo_marker is
not set or undo_retrans is already 0. This happens when sender receives
more DSACK ACKs than packets retransmitted during the current
undo phase. This may also happen when sender receives DSACK after
the undo operation is completed or cancelled.

Fix another bug that undo_retrans is incorrectly incremented when
sender retransmits an skb and tcp_skb_pcount(skb) > 1 (TSO). This case
is rare but not impossible.

Signed-off-by: Yuchung Cheng 
Acked-by: Ilpo Järvinen 
Signed-off-by: David S. Miller

tcp: fix inet_twsk_deschedule()

2011-02-20T02:59:04+00:00

Eric W. Biederman reported a lockdep splat in inet_twsk_deschedule()

This is caused by inet_twsk_purge(), run from process context,
and commit 575f4cd5a5b6394577 (net: Use rcu lookups in inet_twsk_purge.)
removed the BH disabling that was necessary.

Add the BH disabling but fine grained, right before calling
inet_twsk_deschedule(), instead of whole function.

With help from Linus Torvalds and Eric W. Biederman

Reported-by: Eric W. Biederman 
Signed-off-by: Eric Dumazet 
CC: Daniel Lezcano 
CC: Pavel Emelyanov 
CC: Arnaldo Carvalho de Melo 
CC: stable  (# 2.6.33+)
Signed-off-by: David S. Miller

net: provide default_advmss() methods to blackhole dst_ops

2011-02-18T19:39:01+00:00

Commit 0dbaee3b37e118a (net: Abstract default ADVMSS behind an
accessor.) introduced a possible crash in tcp_connect_init(), when
dst->default_advmss() is called from dst_metric_advmss()

Reported-by: George Spelvin 
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

arp_notify: unconditionally send gratuitous ARP for NETDEV_NOTIFY_PEERS.

2011-02-15T01:47:15+00:00

NETDEV_NOTIFY_PEER is an explicit request by the driver to send a link
notification while NETDEV_UP/NETDEV_CHANGEADDR generate link
notifications as a sort of side effect.

In the later cases the sysctl option is present because link
notification events can have undesired effects e.g. if the link is
flapping. I don't think this applies in the case of an explicit
request from a driver.

This patch makes NETDEV_NOTIFY_PEER unconditional, if preferred we
could add a new sysctl for this case which defaults to on.

This change causes Xen post-migration ARP notifications (which cause
switches to relearn their MAC tables etc) to be sent by default.

Signed-off-by: Ian Campbell 
Signed-off-by: David S. Miller

ip_gre: Add IPPROTO_GRE to flowi in ipgre_tunnel_xmit

2011-02-11T19:23:12+00:00

Commit 5811662b15db018c740c57d037523683fd3e6123 ("net: use the macros
defined for the members of flowi") accidentally removed the setting of
IPPROTO_GRE from the struct flowi in ipgre_tunnel_xmit. This patch
restores it.

Signed-off-by: Steffen Klassert 
Acked-by: Changli Gao 
Signed-off-by: David S. Miller

net: Support compat SIOCGETVIFCNT ioctl in ipv4.

2011-02-04T01:24:28+00:00

Signed-off-by: David S. Miller

net: Fix bug in compat SIOCGETSGCNT handling.

2011-02-04T01:21:31+00:00

Commit 709b46e8d90badda1898caea50483c12af178e96 ("net: Add compat
ioctl support for the ipv4 multicast ioctl SIOCGETSGCNT") added the
correct plumbing to handle SIOCGETSGCNT properly.

However, whilst definiting a proper "struct compat_sioc_sg_req" it
isn't actually used in ipmr_compat_ioctl().

Correct this oversight.

Signed-off-by: David S. Miller