linux-stable.git/net/ipv4/udp.c, branch linux-3.0.y

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

2013-07-28T23:18:39+00:00

[ Upstream commit 8822b64a0fa64a5dd1dfcf837c5b0be83f8c05d1 ]

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.)

Signed-off-by: Hannes Frederic Sowa 
Cc: Dave Jones 
Cc: YOSHIFUJI Hideaki 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: refine {udp|tcp|sctp}_mem limits

2011-07-07T07:27:05+00:00

Current tcp/udp/sctp global memory limits are not taking into account
hugepages allocations, and allow 50% of ram to be used by buffers of a
single protocol [ not counting space used by sockets / inodes ...]

Lets use nr_free_buffer_pages() and allow a default of 1/8 of kernel ram
per protocol, and a minimum of 128 pages.
Heavy duty machines sysadmins probably need to tweak limits anyway.


References: https://bugzilla.stlinux.com/show_bug.cgi?id=38032
Reported-by: starlight 
Suggested-by: Andrew Morton 
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

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

2011-06-22T05:34:27+00:00

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

net: convert %p usage to %pK

2011-05-24T05:13:12+00:00

The %pK format specifier is designed to hide exposed kernel pointers,
specifically via /proc interfaces.  Exposing these pointers provides an
easy target for kernel write vulnerabilities, since they reveal the
locations of writable structures containing easily triggerable function
pointers.  The behavior of %pK depends on the kptr_restrict sysctl.

If kptr_restrict is set to 0, no deviation from the standard %p behavior
occurs.  If kptr_restrict is set to 1, the default, if the current user
(intended to be a reader via seq_printf(), etc.) does not have CAP_SYSLOG
(currently in the LSM tree), kernel pointers using %pK are printed as 0's.
 If kptr_restrict is set to 2, kernel pointers using %pK are printed as
0's regardless of privileges.  Replacing with 0's was chosen over the
default "(null)", which cannot be parsed by userland %p, which expects
"(nil)".

The supporting code for kptr_restrict and %pK are currently in the -mm
tree.  This patch converts users of %p in net/ to %pK.  Cases of printing
pointers to the syslog are not covered, since this would eliminate useful
information for postmortem debugging and the reading of the syslog is
already optionally protected by the dmesg_restrict sysctl.

Signed-off-by: Dan Rosenberg 
Cc: James Morris 
Cc: Eric Dumazet 
Cc: Thomas Graf 
Cc: Eugene Teo 
Cc: Kees Cook 
Cc: Ingo Molnar 
Cc: David S. Miller 
Cc: Peter Zijlstra 
Cc: Eric Paris 
Signed-off-by: Andrew Morton 
Signed-off-by: David S. Miller

ipv4: udp: Eliminate remaining uses of rt->rt_src

2011-05-10T20:32:47+00:00

We already track and pass around the correct flow key,
so simply use it in udp_send_skb().

Signed-off-by: David S. Miller

ipv4: Pass flow key down into ip_append_*().

2011-05-09T04:24:07+00:00

This way rt->rt_dst accesses are unnecessary.

Signed-off-by: David S. Miller

ipv4: Pass flow keys down into datagram packet building engine.

2011-05-09T04:24:06+00:00

This way ip_output.c no longer needs rt->rt_{src,dst}.

We already have these keys sitting, ready and waiting, on the stack or
in a socket structure.

Signed-off-by: David S. Miller

udp: Use flow key information instead of rt->rt_{src,dst}

2011-05-09T04:12:48+00:00

We have two cases.

Either the socket is in TCP_ESTABLISHED state and connect() filled
in the inet socket cork flow, or we looked up the route here and
used an on-stack flow.

Track which one it was, and use it to obtain src/dst addrs.

Signed-off-by: David S. Miller

inet: add RCU protection to inet->opt

2011-04-28T20:16:35+00:00

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

inet: constify ip headers and in6_addr

2011-04-22T18:04:14+00:00

Add const qualifiers to structs iphdr, ipv6hdr and in6_addr pointers
where possible, to make code intention more obvious.

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