linux-stable.git/net/ipv4, branch v3.2.78

udp: properly support MSG_PEEK with truncated buffers

2016-01-22T21:40:10+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

Revert "net: add length argument to skb_copy_and_csum_datagram_iovec"

2016-01-22T21:40:09+00:00

This reverts commit 127500d724f8c43f452610c9080444eedb5eaa6c.  That fixed
the problem of buffer over-reads introduced by backporting commit
89c22d8c3b27 ("net: Fix skb csum races when peeking"), but resulted in
incorrect checksumming for short reads.  It will be replaced with a
complete fix.

Signed-off-by: Ben Hutchings

net: add validation for the socket syscall protocol argument

2015-12-30T02:26:03+00:00

[ Upstream commit 79462ad02e861803b3840cc782248c7359451cd9 ]

郭永刚 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: 郭永刚 
Signed-off-by: Hannes Frederic Sowa 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2: open-code U8_MAX]
Signed-off-by: Ben Hutchings

net: ipmr: fix static mfc/dev leaks on table destruction

2015-12-30T02:26:02+00:00

[ Upstream commit 0e615e9601a15efeeb8942cf7cd4dadba0c8c5a7 ]

When destroying an mrt table the static mfc entries and the static
devices are kept, which leads to devices that can never be destroyed
(because of refcnt taken) and leaked memory, for example:
unreferenced object 0xffff880034c144c0 (size 192):
  comm "mfc-broken", pid 4777, jiffies 4320349055 (age 46001.964s)
  hex dump (first 32 bytes):
    98 53 f0 34 00 88 ff ff 98 53 f0 34 00 88 ff ff  .S.4.....S.4....
    ef 0a 0a 14 01 02 03 04 00 00 00 00 01 00 00 00  ................
  backtrace:
    [] kmemleak_alloc+0x4e/0xb0
    [] kmem_cache_alloc+0x190/0x300
    [] ip_mroute_setsockopt+0x5cb/0x910
    [] do_ip_setsockopt.isra.11+0x105/0xff0
    [] ip_setsockopt+0x30/0xa0
    [] raw_setsockopt+0x33/0x90
    [] sock_common_setsockopt+0x14/0x20
    [] SyS_setsockopt+0x71/0xc0
    [] entry_SYSCALL_64_fastpath+0x16/0x7a
    [] 0xffffffffffffffff

Make sure that everything is cleaned on netns destruction.

Signed-off-by: Nikolay Aleksandrov 
Reviewed-by: Cong Wang 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

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

2015-12-30T02:26:01+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

ipv4: igmp: Allow removing groups from a removed interface

2015-12-30T02:25:59+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

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

2015-11-27T12:48:25+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

net: add length argument to skb_copy_and_csum_datagram_iovec

2015-11-17T15:54:45+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

ipv6: lock socket in ip6_datagram_connect()

2015-10-13T02:46:12+00:00

[ Upstream commit 03645a11a570d52e70631838cb786eb4253eb463 ]

ip6_datagram_connect() is doing a lot of socket changes without
socket being locked.

This looks wrong, at least for udp_lib_rehash() which could corrupt
lists because of concurrent udp_sk(sk)->udp_portaddr_hash accesses.

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

inet: frags: fix defragmented packet's IP header for af_packet

2015-08-12T14:33:22+00:00

commit 0848f6428ba3a2e42db124d41ac6f548655735bf upstream.

When ip_frag_queue() computes positions, it assumes that the passed
sk_buff does not contain L2 headers.

However, when PACKET_FANOUT_FLAG_DEFRAG is used, IP reassembly
functions can be called on outgoing packets that contain L2 headers.

Also, IPv4 checksum is not corrected after reassembly.

Fixes: 7736d33f4262 ("packet: Add pre-defragmentation support for ipv4 fanouts.")
Signed-off-by: Edward Hyunkoo Jee 
Signed-off-by: Eric Dumazet 
Cc: Willem de Bruijn 
Cc: Jerry Chu 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings