linux-stable.git/net/ipv4, branch linux-2.6.32.y

tcp: initialize tp->copied_seq in case of cross SYN connection

2016-01-29T21:12:49+00:00

[ Upstream commit 142a2e7ece8d8ac0e818eb2c91f99ca894730e2a ]

Dmitry provided a syzkaller (http://github.com/google/syzkaller)
generated program that triggers the WARNING at
net/ipv4/tcp.c:1729 in tcp_recvmsg() :

WARN_ON(tp->copied_seq != tp->rcv_nxt &&
        !(flags & (MSG_PEEK | MSG_TRUNC)));

His program is specifically attempting a Cross SYN TCP exchange,
that we support (for the pleasure of hackers ?), but it looks we
lack proper tcp->copied_seq initialization.

Thanks again Dmitry for your report and testings.

Signed-off-by: Eric Dumazet 
Reported-by: Dmitry Vyukov 
Tested-by: Dmitry Vyukov 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings 
(cherry picked from commit 6cfa9781d3bf950eed455369966bbdf9d05871c5)
Signed-off-by: Willy Tarreau

ipv4: igmp: Allow removing groups from a removed interface

2016-01-29T21:12:47+00:00

commit 4eba7bb1d72d9bde67d810d09bf62dc207b63c5c upstream.

When a multicast group is joined on a socket, a struct ip_mc_socklist
is appended to the sockets mc_list containing information about the
joined group.

If the interface is hot unplugged, this entry becomes stale. Prior to
commit 52ad353a5344f ("igmp: fix the problem when mc leave group") it
was possible to remove the stale entry by performing a
IP_DROP_MEMBERSHIP, passing either the old ifindex or ip address on
the interface. However, this fix enforces that the interface must
still exist. Thus with time, the number of stale entries grows, until
sysctl_igmp_max_memberships is reached and then it is not possible to
join and more groups.

The previous patch fixes an issue where a IP_DROP_MEMBERSHIP is
performed without specifying the interface, either by ifindex or ip
address. However here we do supply one of these. So loosen the
restriction on device existence to only apply when the interface has
not been specified. This then restores the ability to clean up the
stale entries.

Signed-off-by: Andrew Lunn 
Fixes: 52ad353a5344f "(igmp: fix the problem when mc leave group")
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings 
(cherry picked from commit b1fa852672fb1ea4b0e34bfa1136bb65dba66151)
Signed-off-by: Willy Tarreau

net: add validation for the socket syscall protocol argument

2016-01-29T21:12:42+00:00

commit 79462ad02e861803b3840cc782248c7359451cd9 upstream.

éæ°¸å reported that one could simply crash the kernel as root by
using a simple program:

	int socket_fd;
	struct sockaddr_in addr;
	addr.sin_port = 0;
	addr.sin_addr.s_addr = INADDR_ANY;
	addr.sin_family = 10;

	socket_fd = socket(10,3,0x40000000);
	connect(socket_fd , &addr,16);

AF_INET, AF_INET6 sockets actually only support 8-bit protocol
identifiers. inet_sock's skc_protocol field thus is sized accordingly,
thus larger protocol identifiers simply cut off the higher bits and
store a zero in the protocol fields.

This could lead to e.g. NULL function pointer because as a result of
the cut off inet_num is zero and we call down to inet_autobind, which
is NULL for raw sockets.

kernel: Call Trace:
kernel:  [] ? inet_autobind+0x2e/0x70
kernel:  [] inet_dgram_connect+0x54/0x80
kernel:  [] SYSC_connect+0xd9/0x110
kernel:  [] ? ptrace_notify+0x5b/0x80
kernel:  [] ? syscall_trace_enter_phase2+0x108/0x200
kernel:  [] SyS_connect+0xe/0x10
kernel:  [] tracesys_phase2+0x84/0x89

I found no particular commit which introduced this problem.

CVE: CVE-2015-8543
Cc: Cong Wang 
Reported-by: éæ°¸å 
Signed-off-by: Hannes Frederic Sowa 
Signed-off-by: David S. Miller 
[bwh: Backported to 2.6.32: open-code U8_MAX; adjust context]
Signed-off-by: Ben Hutchings 
Signed-off-by: Willy Tarreau

udp: properly support MSG_PEEK with truncated buffers

2016-01-29T21:12:41+00:00

commit 197c949e7798fbf28cfadc69d9ca0c2abbf93191 upstream.

Backport of this upstream commit into stable kernels :
89c22d8c3b27 ("net: Fix skb csum races when peeking")
exposed a bug in udp stack vs MSG_PEEK support, when user provides
a buffer smaller than skb payload.

In this case,
skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr),
                                 msg->msg_iov);
returns -EFAULT.

This bug does not happen in upstream kernels since Al Viro did a great
job to replace this into :
skb_copy_and_csum_datagram_msg(skb, sizeof(struct udphdr), msg);
This variant is safe vs short buffers.

For the time being, instead reverting Herbert Xu patch and add back
skb->ip_summed invalid changes, simply store the result of
udp_lib_checksum_complete() so that we avoid computing the checksum a
second time, and avoid the problematic
skb_copy_and_csum_datagram_iovec() call.

This patch can be applied on recent kernels as it avoids a double
checksumming, then backported to stable kernels as a bug fix.

Signed-off-by: Eric Dumazet 
Acked-by: Herbert Xu 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings 
(cherry picked from commit 18a6eba2eabbcb50a78210b16f7dd43d888a537b)
Signed-off-by: Willy Tarreau

Revert "net: add length argument to skb_copy_and_csum_datagram_iovec"

2016-01-29T21:12:40+00:00

This reverts commit c507639ba963bb47e3f515670a7cace76af76ab6.
As reported by Michal Kubecek, this fix doesn't handle truncated
reads correctly. Next patch from Eric fixes it better.

Signed-off-by: Willy Tarreau

ipmr: fix possible race resulting from improper usage of IP_INC_STATS_BH() in preemptible context.

2015-12-05T23:49:19+00:00

[ Upstream commit 44f49dd8b5a606870a1f21101522a0f9c4414784 ]

Fixes the following kernel BUG :

BUG: using __this_cpu_add() in preemptible [00000000] code: bash/2758
caller is __this_cpu_preempt_check+0x13/0x15
CPU: 0 PID: 2758 Comm: bash Tainted: P           O   3.18.19 #2
 ffffffff8170eaca ffff880110d1b788 ffffffff81482b2a 0000000000000000
 0000000000000000 ffff880110d1b7b8 ffffffff812010ae ffff880007cab800
 ffff88001a060800 ffff88013a899108 ffff880108b84240 ffff880110d1b7c8
Call Trace:
[] dump_stack+0x52/0x80
[] check_preemption_disabled+0xce/0xe1
[] __this_cpu_preempt_check+0x13/0x15
[] ipmr_queue_xmit+0x647/0x70c
[] ip_mr_forward+0x32f/0x34e
[] ip_mroute_setsockopt+0xe03/0x108c
[] ? get_parent_ip+0x11/0x42
[] ? pollwake+0x4d/0x51
[] ? default_wake_function+0x0/0xf
[] ? get_parent_ip+0x11/0x42
[] ? __wake_up_common+0x45/0x77
[] ? _raw_spin_unlock_irqrestore+0x1d/0x32
[] ? __wake_up_sync_key+0x4a/0x53
[] ? sock_def_readable+0x71/0x75
[] do_ip_setsockopt+0x9d/0xb55
[] ? unix_seqpacket_sendmsg+0x3f/0x41
[] ? sock_sendmsg+0x6d/0x86
[] ? sockfd_lookup_light+0x12/0x5d
[] ? SyS_sendto+0xf3/0x11b
[] ? new_sync_read+0x82/0xaa
[] compat_ip_setsockopt+0x3b/0x99
[] compat_raw_setsockopt+0x11/0x32
[] compat_sock_common_setsockopt+0x18/0x1f
[] compat_SyS_setsockopt+0x1a9/0x1cf
[] compat_SyS_socketcall+0x180/0x1e3
[] cstar_dispatch+0x7/0x1e

Signed-off-by: Ani Sinha 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2: ipmr doesn't implement IPSTATS_MIB_OUTOCTETS]
Signed-off-by: Ben Hutchings 
(cherry picked from commit 33cf84ba8c25b40c7de52029efc8d4372725c95f)

Signed-off-by: Willy Tarreau

net: add length argument to skb_copy_and_csum_datagram_iovec

2015-12-05T23:49:13+00:00

Without this length argument, we can read past the end of the iovec in
memcpy_toiovec because we have no way of knowing the total length of the
iovec's buffers.

This is needed for stable kernels where 89c22d8c3b27 ("net: Fix skb
csum races when peeking") has been backported but that don't have the
ioviter conversion, which is almost all the stable trees <= 3.18.

This also fixes a kernel crash for NFS servers when the client uses
 -onfsvers=3,proto=udp to mount the export.

Signed-off-by: Sabrina Dubroca 
Reviewed-by: Hannes Frederic Sowa 
[bwh: Backported to 3.2: adjust context in include/linux/skbuff.h]
Signed-off-by: Ben Hutchings 
(cherry picked from commit 127500d724f8c43f452610c9080444eedb5eaa6c)

Signed-off-by: Willy Tarreau

udp: fix behavior of wrong checksums

2015-09-18T11:51:57+00:00

commit beb39db59d14990e401e235faf66a6b9b31240b0 upstream.

We have two problems in UDP stack related to bogus checksums :

1) We return -EAGAIN to application even if receive queue is not empty.
   This breaks applications using edge trigger epoll()

2) Under UDP flood, we can loop forever without yielding to other
   processes, potentially hanging the host, especially on non SMP.

This patch is an attempt to make things better.

We might in the future add extra support for rt applications
wanting to better control time spent doing a recv() in a hostile
environment. For example we could validate checksums before queuing
packets in socket receive queue.

Signed-off-by: Eric Dumazet 
Cc: Willem de Bruijn 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings 

CVE-2015-5364
CVE-2015-5366

Signed-off-by: Willy Tarreau

net: fix incorrect backport of tcp_send_fin in 2.6.32.66

2015-06-03T15:12:46+00:00

Eric forwarded this bug report happening since 2.6.32.66, found that the
backport of commit 845704a5 ("tcp: avoid looping in tcp_send_fin()") was
incorrect and proposed this patch to fix it. The bug was also reported by
starlight.2015q2@binnacle.cx who confirmed the fix.

> Date: Fri, 29 May 2015 09:12:45 +0000
> From: "bugzilla-daemon@bugzilla.kernel.org" 
> To: "shemminger@linux-foundation.org" 
> Subject: [Bug 99161] New: 2.6.32.66 PPC Oops in tcp_send_fin
>
>
> https://bugzilla.kernel.org/show_bug.cgi?id=99161
>
>             Bug ID: 99161
>            Summary: 2.6.32.66 PPC Oops in tcp_send_fin
>            Product: Networking
>            Version: 2.5
>     Kernel Version: 2.6.32.66
>           Hardware: PPC-32
>                 OS: Linux
>               Tree: Mainline
>             Status: NEW
>           Severity: normal
>           Priority: P1
>          Component: IPV4
>           Assignee: shemminger@linux-foundation.org
>           Reporter: varenet@parisc-linux.org
>         Regression: No
>
> I just updated my trusty old PPC box to longterm 2.6.32.66 (was running .65
> before that with zero issue) and it started spewing oopses at me like hell
> broke loose. This machine is primarily used as a DNS and MX (albeit under low
> pressure).
(...)

Cc: Eric Dumazet 
Signed-off-by: Willy Tarreau

ipv4: fix nexthop attlen check in fib_nh_match

2015-05-24T08:10:53+00:00

commit f76936d07c4eeb36d8dbb64ebd30ab46ff85d9f7 upstream.

fib_nh_match does not match nexthops correctly. Example:

ip route add 172.16.10/24 nexthop via 192.168.122.12 dev eth0 \
                          nexthop via 192.168.122.13 dev eth0
ip route del 172.16.10/24 nexthop via 192.168.122.14 dev eth0 \
                          nexthop via 192.168.122.15 dev eth0

Del command is successful and route is removed. After this patch
applied, the route is correctly matched and result is:
RTNETLINK answers: No such process

Please consider this for stable trees as well.

Fixes: 4e902c57417c4 ("[IPv4]: FIB configuration using struct fib_config")
Signed-off-by: Jiri Pirko 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings 
(cherry picked from commit 0aba46add2915b344580569e87d9c41274b9c475)

Signed-off-by: Willy Tarreau