linux-stable.git/net/ipv6, branch linux-2.6.34.y

ipv6: call udp_push_pending_frames when uncorking a socket with AF_INET pending data

2014-02-10T21:10:45+00:00

commit 8822b64a0fa64a5dd1dfcf837c5b0be83f8c05d1 upstream.

We accidentally call down to ip6_push_pending_frames when uncorking
pending AF_INET data on a ipv6 socket. This results in the following
splat (from Dave Jones):

skbuff: skb_under_panic: text:ffffffff816765f6 len:48 put:40 head:ffff88013deb6df0 data:ffff88013deb6dec tail:0x2c end:0xc0 dev:
------------[ cut here ]------------
kernel BUG at net/core/skbuff.c:126!
invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
Modules linked in: dccp_ipv4 dccp 8021q garp bridge stp dlci mpoa snd_seq_dummy sctp fuse hidp tun bnep nfnetlink scsi_transport_iscsi rfcomm can_raw can_bcm af_802154 appletalk caif_socket can caif ipt_ULOG x25 rose af_key pppoe pppox ipx phonet irda llc2 ppp_generic slhc p8023 psnap p8022 llc crc_ccitt atm bluetooth
+netrom ax25 nfc rfkill rds af_rxrpc coretemp hwmon kvm_intel kvm crc32c_intel snd_hda_codec_realtek ghash_clmulni_intel microcode pcspkr snd_hda_codec_hdmi snd_hda_intel snd_hda_codec snd_hwdep usb_debug snd_seq snd_seq_device snd_pcm e1000e snd_page_alloc snd_timer ptp snd pps_core soundcore xfs libcrc32c
CPU: 2 PID: 8095 Comm: trinity-child2 Not tainted 3.10.0-rc7+ #37
task: ffff8801f52c2520 ti: ffff8801e6430000 task.ti: ffff8801e6430000
RIP: 0010:[]  [] skb_panic+0x63/0x65
RSP: 0018:ffff8801e6431de8  EFLAGS: 00010282
RAX: 0000000000000086 RBX: ffff8802353d3cc0 RCX: 0000000000000006
RDX: 0000000000003b90 RSI: ffff8801f52c2ca0 RDI: ffff8801f52c2520
RBP: ffff8801e6431e08 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: ffff88022ea0c800
R13: ffff88022ea0cdf8 R14: ffff8802353ecb40 R15: ffffffff81cc7800
FS:  00007f5720a10740(0000) GS:ffff880244c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000005862000 CR3: 000000022843c000 CR4: 00000000001407e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Stack:
 ffff88013deb6dec 000000000000002c 00000000000000c0 ffffffff81a3f6e4
 ffff8801e6431e18 ffffffff8159a9aa ffff8801e6431e90 ffffffff816765f6
 ffffffff810b756b 0000000700000002 ffff8801e6431e40 0000fea9292aa8c0
Call Trace:
 [] skb_push+0x3a/0x40
 [] ip6_push_pending_frames+0x1f6/0x4d0
 [] ? mark_held_locks+0xbb/0x140
 [] udp_v6_push_pending_frames+0x2b9/0x3d0
 [] ? udplite_getfrag+0x20/0x20
 [] udp_lib_setsockopt+0x1aa/0x1f0
 [] ? fget_light+0x387/0x4f0
 [] udpv6_setsockopt+0x34/0x40
 [] sock_common_setsockopt+0x14/0x20
 [] SyS_setsockopt+0x71/0xd0
 [] tracesys+0xdd/0xe2
Code: 00 00 48 89 44 24 10 8b 87 d8 00 00 00 48 89 44 24 08 48 8b 87 e8 00 00 00 48 c7 c7 c0 04 aa 81 48 89 04 24 31 c0 e8 e1 7e ff ff <0f> 0b 55 48 89 e5 0f 0b 55 48 89 e5 0f 0b 55 48 89 e5 0f 0b 55
RIP  [] skb_panic+0x63/0x65
 RSP 

This patch adds a check if the pending data is of address family AF_INET
and directly calls udp_push_ending_frames from udp_v6_push_pending_frames
if that is the case.

This bug was found by Dave Jones with trinity.

(Also move the initialization of fl6 below the AF_INET check, even if
not strictly necessary.)

Cc: Dave Jones 
Cc: YOSHIFUJI Hideaki 
Signed-off-by: Hannes Frederic Sowa 
Signed-off-by: David S. Miller 
[PG: The line "flowi6 *fl6 = &inet->cork.fl.u.ip6"  was
              "flowi *fl = &inet->cork.fl" in 2.6.34 kernel.]
Signed-off-by: Paul Gortmaker

inet: add RCU protection to inet->opt

2014-02-10T21:10:42+00:00

commit f6d8bd051c391c1c0458a30b2a7abcd939329259 upstream.

We lack proper synchronization to manipulate inet->opt ip_options

Problem is ip_make_skb() calls ip_setup_cork() and
ip_setup_cork() possibly makes a copy of ipc->opt (struct ip_options),
without any protection against another thread manipulating inet->opt.

Another thread can change inet->opt pointer and free old one under us.

Use RCU to protect inet->opt (changed to inet->inet_opt).

Instead of handling atomic refcounts, just copy ip_options when
necessary, to avoid cache line dirtying.

We cant insert an rcu_head in struct ip_options since its included in
skb->cb[], so this patch is large because I had to introduce a new
ip_options_rcu structure.

Signed-off-by: Eric Dumazet 
Cc: Herbert Xu 
Signed-off-by: David S. Miller 
[dannf/bwh: backported to Debian's 2.6.32]
Signed-off-by: Ben Hutchings 
Signed-off-by: Willy Tarreau 
[PG: use 2.6.32 patch, since it is closer to 2.6.34 than original
 baseline; drop net/l2tp/l2tp_ip.c chunk as we don't have that file]
Signed-off-by: Paul Gortmaker

ipv6: Add GSO support on forwarding path

2012-08-17T19:35:09+00:00

commit 0aa68271510ae2b221d4b60892103837be63afe4 upstream.

Currently we disallow GSO packets on the IPv6 forward path.
This patch fixes this.

Note that I discovered that our existing GSO MTU checks (e.g.,
IPv4 forwarding) are buggy in that they skip the check altogether,
when they really should be checking gso_size + header instead.

I have also been lazy here in that I haven't bothered to segment
the GSO packet by hand before generating an ICMP message.  Someone
should add that to be 100% correct.

Reported-by: Ralf Baechle 
Signed-off-by: Herbert Xu 
Signed-off-by: David S. Miller 
Signed-off-by: Paul Gortmaker

net: Compute protocol sequence numbers and fragment IDs using MD5.

2012-05-17T15:21:27+00:00

commit 6e5714eaf77d79ae1c8b47e3e040ff5411b717ec upstream.

Computers have become a lot faster since we compromised on the
partial MD4 hash which we use currently for performance reasons.

MD5 is a much safer choice, and is inline with both RFC1948 and
other ISS generators (OpenBSD, Solaris, etc.)

Furthermore, only having 24-bits of the sequence number be truly
unpredictable is a very serious limitation.  So the periodic
regeneration and 8-bit counter have been removed.  We compute and
use a full 32-bit sequence number.

For ipv6, DCCP was found to use a 32-bit truncated initial sequence
number (it needs 43-bits) and that is fixed here as well.

Reported-by: Dan Kaminsky 
Tested-by: Willy Tarreau 
Signed-off-by: David S. Miller 
[PG: diffstat vs. 6e5714 differs, since no secure_ipv6_id to delete in 34]
Signed-off-by: Paul Gortmaker

udp/recvmsg: Clear MSG_TRUNC flag when starting over for a new packet

2012-05-17T15:21:07+00:00

commit 9cfaa8def1c795a512bc04f2aec333b03724ca2e upstream.

Consider this scenario: When the size of the first received udp packet
is bigger than the receive buffer, MSG_TRUNC bit is set in msg->msg_flags.
However, if checksum error happens and this is a blocking socket, it will
goto try_again loop to receive the next packet.  But if the size of the
next udp packet is smaller than receive buffer, MSG_TRUNC flag should not
be set, but because MSG_TRUNC bit is not cleared in msg->msg_flags before
receive the next packet, MSG_TRUNC is still set, which is wrong.

Fix this problem by clearing MSG_TRUNC flag when starting over for a
new packet.

Signed-off-by: Xufeng Zhang 
Signed-off-by: Paul Gortmaker 
Signed-off-by: David S. Miller 
Signed-off-by: Paul Gortmaker

ipv6/udp: Use the correct variable to determine non-blocking condition

2012-05-17T15:21:07+00:00

commit 32c90254ed4a0c698caa0794ebb4de63fcc69631 upstream.

udpv6_recvmsg() function is not using the correct variable to determine
whether or not the socket is in non-blocking operation, this will lead
to unexpected behavior when a UDP checksum error occurs.

Consider a non-blocking udp receive scenario: when udpv6_recvmsg() is
called by sock_common_recvmsg(), MSG_DONTWAIT bit of flags variable in
udpv6_recvmsg() is cleared by "flags & ~MSG_DONTWAIT" in this call:

    err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
                   flags & ~MSG_DONTWAIT, &addr_len);

i.e. with udpv6_recvmsg() getting these values:

	int noblock = flags & MSG_DONTWAIT
	int flags = flags & ~MSG_DONTWAIT

So, when udp checksum error occurs, the execution will go to
csum_copy_err, and then the problem happens:

    csum_copy_err:
            ...............
            if (flags & MSG_DONTWAIT)
                    return -EAGAIN;
            goto try_again;
            ...............

But it will always go to try_again as MSG_DONTWAIT has been cleared
from flags at call time -- only noblock contains the original value
of MSG_DONTWAIT, so the test should be:

            if (noblock)
                    return -EAGAIN;

This is also consistent with what the ipv4/udp code does.

Signed-off-by: Xufeng Zhang 
Signed-off-by: Paul Gortmaker 
Signed-off-by: David S. Miller 
Signed-off-by: Paul Gortmaker

netfilter: IPv6: initialize TOS field in REJECT target module

2012-05-17T15:20:52+00:00

commit 4319cc0cf5bb894b7368008cdf6dd20eb8868018 upstream.

The IPv6 header is not zeroed out in alloc_skb so we must initialize
it properly unless we want to see IPv6 packets with random TOS fields
floating around. The current implementation resets the flow label
but this could be changed if deemed necessary.

We stumbled upon this issue when trying to apply a mangle rule to
the RST packet generated by the REJECT target module.

Signed-off-by: Fernando Luis Vazquez Cao 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Paul Gortmaker

net: sk_add_backlog() take rmem_alloc into account

2012-03-14T14:58:05+00:00

commit c377411f2494a931ff7facdbb3a6839b1266bcf6 upstream.

Current socket backlog limit is not enough to really stop DDOS attacks,
because user thread spend many time to process a full backlog each
round, and user might crazy spin on socket lock.

We should add backlog size and receive_queue size (aka rmem_alloc) to
pace writers, and let user run without being slow down too much.

Introduce a sk_rcvqueues_full() helper, to avoid taking socket lock in
stress situations.

Under huge stress from a multiqueue/RPS enabled NIC, a single flow udp
receiver can now process ~200.000 pps (instead of ~100 pps before the
patch) on a 8 core machine.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Paul Gortmaker

ipv6: udp: fix the wrong headroom check

2012-03-14T14:58:03+00:00

commit a9cf73ea7ff78f52662c8658d93c226effbbedde upstream.

At this point, skb->data points to skb_transport_header.
So, headroom check is wrong.

For some case:bridge(UFO is on) + eth device(UFO is off),
there is no enough headroom for IPv6 frag head.
But headroom check is always false.

This will bring about data be moved to there prior to skb->head,
when adding IPv6 frag header to skb.

Signed-off-by: Shan Wei 
Acked-by: Herbert Xu 
Signed-off-by: David S. Miller 
Signed-off-by: Paul Gortmaker

ipv6: Silence privacy extensions initialization

2012-03-14T14:57:50+00:00

commit 2fdc1c8093255f9da877d7b9ce3f46c2098377dc upstream.

When a network namespace is created (via CLONE_NEWNET), the loopback
interface is automatically added to the new namespace, triggering a
printk in ipv6_add_dev() if CONFIG_IPV6_PRIVACY is set.

This is problematic for applications which use CLONE_NEWNET as
part of a sandbox, like Chromium's suid sandbox or recent versions of
vsftpd. On a busy machine, it can lead to thousands of useless
"lo: Disabled Privacy Extensions" messages appearing in dmesg.

It's easy enough to check the status of privacy extensions via the
use_tempaddr sysctl, so just removing the printk seems like the most
sensible solution.

Signed-off-by: Romain Francoise 
Signed-off-by: David S. Miller 
Signed-off-by: Paul Gortmaker