linux-toradex.git/net/sctp, branch v3.4.10

sctp: Fix list corruption resulting from freeing an association on a list

2012-08-09T15:31:42+00:00

[ Upstream commit 2eebc1e188e9e45886ee00662519849339884d6d ]

A few days ago Dave Jones reported this oops:

[22766.294255] general protection fault: 0000 [#1] PREEMPT SMP
[22766.295376] CPU 0
[22766.295384] Modules linked in:
[22766.387137]  ffffffffa169f292 6b6b6b6b6b6b6b6b ffff880147c03a90
ffff880147c03a74
[22766.387135] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 00000000000
[22766.387136] Process trinity-watchdo (pid: 10896, threadinfo ffff88013e7d2000,
[22766.387137] Stack:
[22766.387140]  ffff880147c03a10
[22766.387140]  ffffffffa169f2b6
[22766.387140]  ffff88013ed95728
[22766.387143]  0000000000000002
[22766.387143]  0000000000000000
[22766.387143]  ffff880003fad062
[22766.387144]  ffff88013c120000
[22766.387144]
[22766.387145] Call Trace:
[22766.387145]  
[22766.387150]  [] ? __sctp_lookup_association+0x62/0xd0
[sctp]
[22766.387154]  [] __sctp_lookup_association+0x86/0xd0 [sctp]
[22766.387157]  [] sctp_rcv+0x207/0xbb0 [sctp]
[22766.387161]  [] ? trace_hardirqs_off_caller+0x28/0xd0
[22766.387163]  [] ? nf_hook_slow+0x133/0x210
[22766.387166]  [] ? ip_local_deliver_finish+0x4c/0x4c0
[22766.387168]  [] ip_local_deliver_finish+0x18d/0x4c0
[22766.387169]  [] ? ip_local_deliver_finish+0x4c/0x4c0
[22766.387171]  [] ip_local_deliver+0x47/0x80
[22766.387172]  [] ip_rcv_finish+0x150/0x680
[22766.387174]  [] ip_rcv+0x214/0x320
[22766.387176]  [] __netif_receive_skb+0x7b7/0x910
[22766.387178]  [] ? __netif_receive_skb+0x11c/0x910
[22766.387180]  [] ? put_lock_stats.isra.25+0xe/0x40
[22766.387182]  [] netif_receive_skb+0x23/0x1f0
[22766.387183]  [] ? dev_gro_receive+0x139/0x440
[22766.387185]  [] napi_skb_finish+0x70/0xa0
[22766.387187]  [] napi_gro_receive+0xf5/0x130
[22766.387218]  [] e1000_receive_skb+0x59/0x70 [e1000e]
[22766.387242]  [] e1000_clean_rx_irq+0x28b/0x460 [e1000e]
[22766.387266]  [] e1000e_poll+0x78/0x430 [e1000e]
[22766.387268]  [] net_rx_action+0x1aa/0x3d0
[22766.387270]  [] ? account_system_vtime+0x10f/0x130
[22766.387273]  [] __do_softirq+0xe0/0x420
[22766.387275]  [] call_softirq+0x1c/0x30
[22766.387278]  [] do_softirq+0xd5/0x110
[22766.387279]  [] irq_exit+0xd5/0xe0
[22766.387281]  [] do_IRQ+0x63/0xd0
[22766.387283]  [] common_interrupt+0x6f/0x6f
[22766.387283]  
[22766.387284]
[22766.387285]  [] ? retint_swapgs+0x13/0x1b
[22766.387285] Code: c0 90 5d c3 66 0f 1f 44 00 00 4c 89 c8 5d c3 0f 1f 00 55 48
89 e5 48 83
ec 20 48 89 5d e8 4c 89 65 f0 4c 89 6d f8 66 66 66 66 90 <0f> b7 87 98 00 00 00
48 89 fb
49 89 f5 66 c1 c0 08 66 39 46 02
[22766.387307]
[22766.387307] RIP
[22766.387311]  [] sctp_assoc_is_match+0x19/0x90 [sctp]
[22766.387311]  RSP 
[22766.387142]  ffffffffa16ab120
[22766.599537] ---[ end trace 3f6dae82e37b17f5 ]---
[22766.601221] Kernel panic - not syncing: Fatal exception in interrupt

It appears from his analysis and some staring at the code that this is likely
occuring because an association is getting freed while still on the
sctp_assoc_hashtable.  As a result, we get a gpf when traversing the hashtable
while a freed node corrupts part of the list.

Nominally I would think that an mibalanced refcount was responsible for this,
but I can't seem to find any obvious imbalance.  What I did note however was
that the two places where we create an association using
sctp_primitive_ASSOCIATE (__sctp_connect and sctp_sendmsg), have failure paths
which free a newly created association after calling sctp_primitive_ASSOCIATE.
sctp_primitive_ASSOCIATE brings us into the sctp_sf_do_prm_asoc path, which
issues a SCTP_CMD_NEW_ASOC side effect, which in turn adds a new association to
the aforementioned hash table.  the sctp command interpreter that process side
effects has not way to unwind previously processed commands, so freeing the
association from the __sctp_connect or sctp_sendmsg error path would lead to a
freed association remaining on this hash table.

I've fixed this but modifying sctp_[un]hash_established to use hlist_del_init,
which allows us to proerly use hlist_unhashed to check if the node is on a
hashlist safely during a delete.  That in turn alows us to safely call
sctp_unhash_established in the __sctp_connect and sctp_sendmsg error paths
before freeing them, regardles of what the associations state is on the hash
list.

I noted, while I was doing this, that the __sctp_unhash_endpoint was using
hlist_unhsashed in a simmilar fashion, but never nullified any removed nodes
pointers to make that function work properly, so I fixed that up in a simmilar
fashion.

I attempted to test this using a virtual guest running the SCTP_RR test from
netperf in a loop while running the trinity fuzzer, both in a loop.  I wasn't
able to recreate the problem prior to this fix, nor was I able to trigger the
failure after (neither of which I suppose is suprising).  Given the trace above
however, I think its likely that this is what we hit.

Signed-off-by: Neil Horman 
Reported-by: davej@redhat.com
CC: davej@redhat.com
CC: "David S. Miller" 
CC: Vlad Yasevich 
CC: Sridhar Samudrala 
CC: linux-sctp@vger.kernel.org
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

sctp: check cached dst before using it

2012-05-11T03:15:47+00:00

dst_check() will take care of SA (and obsolete field), hence
IPsec rekeying scenario is taken into account.

Signed-off-by: Nicolas Dichtel 
Acked-by: Vlad Yaseivch 
Signed-off-by: David S. Miller

sctp: Allow struct sctp_event_subscribe to grow without breaking binaries

2012-04-04T22:05:02+00:00

getsockopt(..., SCTP_EVENTS, ...) performs a length check and returns
an error if the user provides less bytes than the size of struct
sctp_event_subscribe.

Struct sctp_event_subscribe needs to be extended by an u8 for every
new event or notification type that is added.

This obviously makes getsockopt fail for binaries that are compiled
against an older versions of  which do not contain
all event types.

This patch changes getsockopt behaviour to no longer return an error
if not enough bytes are being provided by the user. Instead, it
returns as much of sctp_event_subscribe as fits into the provided buffer.

This leads to the new behavior that users see what they have been aware
of at compile time.

The setsockopt(..., SCTP_EVENTS, ...) API is already behaving like this.

Signed-off-by: Thomas Graf 
Acked-by: Vlad Yasevich 
Signed-off-by: David S. Miller

sctp: Export sctp_do_peeloff

2012-03-08T21:52:08+00:00

lookup sctp_association within sctp_do_peeloff() to enable its use outside of
the sctp code with minimal knowledge of the former.

Signed-off-by: Benjamin Poirier 
Acked-by: Vlad Yasevich 
Signed-off-by: David S. Miller

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial

2012-01-08T21:21:22+00:00

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (53 commits)
  Kconfig: acpi: Fix typo in comment.
  misc latin1 to utf8 conversions
  devres: Fix a typo in devm_kfree comment
  btrfs: free-space-cache.c: remove extra semicolon.
  fat: Spelling s/obsolate/obsolete/g
  SCSI, pmcraid: Fix spelling error in a pmcraid_err() call
  tools/power turbostat: update fields in manpage
  mac80211: drop spelling fix
  types.h: fix comment spelling for 'architectures'
  typo fixes: aera -> area, exntension -> extension
  devices.txt: Fix typo of 'VMware'.
  sis900: Fix enum typo 'sis900_rx_bufer_status'
  decompress_bunzip2: remove invalid vi modeline
  treewide: Fix comment and string typo 'bufer'
  hyper-v: Update MAINTAINERS
  treewide: Fix typos in various parts of the kernel, and fix some comments.
  clockevents: drop unknown Kconfig symbol GENERIC_CLOCKEVENTS_MIGR
  gpio: Kconfig: drop unknown symbol 'CS5535_GPIO'
  leds: Kconfig: Fix typo 'D2NET_V2'
  sound: Kconfig: drop unknown symbol ARCH_CLPS7500
  ...

Fix up trivial conflicts in arch/powerpc/platforms/40x/Kconfig (some new
kconfig additions, close to removed commented-out old ones)

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2011-12-23T22:13:56+00:00

Conflicts:
	net/bluetooth/l2cap_core.c

Just two overlapping changes, one added an initialization of
a local variable, and another change added a new local variable.

Signed-off-by: David S. Miller

sctp: Do not account for sizeof(struct sk_buff) in estimated rwnd

2011-12-20T18:58:37+00:00

When checking whether a DATA chunk fits into the estimated rwnd a
full sizeof(struct sk_buff) is added to the needed chunk size. This
quickly exhausts the available rwnd space and leads to packets being
sent which are much below the PMTU limit. This can lead to much worse
performance.

The reason for this behaviour was to avoid putting too much memory
pressure on the receiver. The concept is not completely irational
because a Linux receiver does in fact clone an skb for each DATA chunk
delivered. However, Linux also reserves half the available socket
buffer space for data structures therefore usage of it is already
accounted for.

When proposing to change this the last time it was noted that this
behaviour was introduced to solve a performance issue caused by rwnd
overusage in combination with small DATA chunks.

Trying to reproduce this I found that with the sk_buff overhead removed,
the performance would improve significantly unless socket buffer limits
are increased.

The following numbers have been gathered using a patched iperf
supporting SCTP over a live 1 Gbit ethernet network. The -l option
was used to limit DATA chunk sizes. The numbers listed are based on
the average of 3 test runs each. Default values have been used for
sk_(r|w)mem.

Chunk
Size    Unpatched     No Overhead
-------------------------------------
   4    15.2 Kbit [!]   12.2 Mbit [!]
   8    35.8 Kbit [!]   26.0 Mbit [!]
  16    95.5 Kbit [!]   54.4 Mbit [!]
  32   106.7 Mbit      102.3 Mbit
  64   189.2 Mbit      188.3 Mbit
 128   331.2 Mbit      334.8 Mbit
 256   537.7 Mbit      536.0 Mbit
 512   766.9 Mbit      766.6 Mbit
1024   810.1 Mbit      808.6 Mbit

Signed-off-by: Thomas Graf 
Signed-off-by: David S. Miller

sctp: fix incorrect overflow check on autoclose

2011-12-19T21:25:46+00:00

Commit 8ffd3208 voids the previous patches f6778aab and 810c0719 for
limiting the autoclose value.  If userspace passes in -1 on 32-bit
platform, the overflow check didn't work and autoclose would be set
to 0xffffffff.

This patch defines a max_autoclose (in seconds) for limiting the value
and exposes it through sysctl, with the following intentions.

1) Avoid overflowing autoclose * HZ.

2) Keep the default autoclose bound consistent across 32- and 64-bit
   platforms (INT_MAX / HZ in this patch).

3) Keep the autoclose value consistent between setsockopt() and
   getsockopt() calls.

Suggested-by: Vlad Yasevich 
Signed-off-by: Xi Wang 
Signed-off-by: David S. Miller

net: use IS_ENABLED(CONFIG_IPV6)

2011-12-11T23:25:16+00:00

Instead of testing defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)

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

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2011-12-02T18:49:21+00:00