linux-toradex.git/net, branch v3.2.28 Linux kernel for Apalis and Colibri modules cfg80211: process pending events when unregistering net device 2012-08-19T17:15:30+00:00 Daniel Drake dsd@laptop.org 2012-08-02T17:41:48+00:00 c506474fed3246e4ea1dcf86809cbd802d57e541 commit 1f6fc43e621167492ed4b7f3b4269c584c3d6ccc upstream. libertas currently calls cfg80211_disconnected() when it is being brought down. This causes an event to be allocated, but since the wdev is already removed from the rdev by the time that the event processing work executes, the event is never processed or freed. http://article.gmane.org/gmane.linux.kernel.wireless.general/95666 Fix this leak, and other possible situations, by processing the event queue when a device is being unregistered. Thanks to Johannes Berg for the suggestion. Signed-off-by: Daniel Drake <dsd@laptop.org> Reviewed-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 1f6fc43e621167492ed4b7f3b4269c584c3d6ccc upstream.

libertas currently calls cfg80211_disconnected() when it is being
brought down. This causes an event to be allocated, but since the
wdev is already removed from the rdev by the time that the event
processing work executes, the event is never processed or freed.
http://article.gmane.org/gmane.linux.kernel.wireless.general/95666

Fix this leak, and other possible situations, by processing the event
queue when a device is being unregistered. Thanks to Johannes Berg for
the suggestion.

Signed-off-by: Daniel Drake <dsd@laptop.org>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
mac80211: cancel mesh path timer 2012-08-19T17:15:28+00:00 Johannes Berg johannes.berg@intel.com 2012-08-01T19:03:21+00:00 afac82f0c92a4c53feab7db8490a1ec731b5bf0a commit dd4c9260e7f23f2e951cbfb2726e468c6d30306c upstream. The mesh path timer needs to be canceled when leaving the mesh as otherwise it could fire after the interface has been removed already. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit dd4c9260e7f23f2e951cbfb2726e468c6d30306c upstream.

The mesh path timer needs to be canceled when
leaving the mesh as otherwise it could fire
after the interface has been removed already.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
tcp: perform DMA to userspace only if there is a task waiting for it 2012-08-19T17:15:25+00:00 Jiri Kosina jkosina@suse.cz 2012-07-27T10:38:50+00:00 789e0ed6c1132db40b4e6349113516ea0f700710 [ Upstream commit 59ea33a68a9083ac98515e4861c00e71efdc49a1 ] Back in 2006, commit 1a2449a87b ("[I/OAT]: TCP recv offload to I/OAT") added support for receive offloading to IOAT dma engine if available. The code in tcp_rcv_established() tries to perform early DMA copy if applicable. It however does so without checking whether the userspace task is actually expecting the data in the buffer. This is not a problem under normal circumstances, but there is a corner case where this doesn't work -- and that's when MSG_TRUNC flag to recvmsg() is used. If the IOAT dma engine is not used, the code properly checks whether there is a valid ucopy.task and the socket is owned by userspace, but misses the check in the dmaengine case. This problem can be observed in real trivially -- for example 'tbench' is a good reproducer, as it makes a heavy use of MSG_TRUNC. On systems utilizing IOAT, you will soon find tbench waiting indefinitely in sk_wait_data(), as they have been already early-copied in tcp_rcv_established() using dma engine. This patch introduces the same check we are performing in the simple iovec copy case to the IOAT case as well. It fixes the indefinite recvmsg(MSG_TRUNC) hangs. Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
[ Upstream commit 59ea33a68a9083ac98515e4861c00e71efdc49a1 ]

Back in 2006, commit 1a2449a87b ("[I/OAT]: TCP recv offload to I/OAT")
added support for receive offloading to IOAT dma engine if available.

The code in tcp_rcv_established() tries to perform early DMA copy if
applicable. It however does so without checking whether the userspace
task is actually expecting the data in the buffer.

This is not a problem under normal circumstances, but there is a corner
case where this doesn't work -- and that's when MSG_TRUNC flag to
recvmsg() is used.

If the IOAT dma engine is not used, the code properly checks whether
there is a valid ucopy.task and the socket is owned by userspace, but
misses the check in the dmaengine case.

This problem can be observed in real trivially -- for example 'tbench' is a
good reproducer, as it makes a heavy use of MSG_TRUNC. On systems utilizing
IOAT, you will soon find tbench waiting indefinitely in sk_wait_data(), as they
have been already early-copied in tcp_rcv_established() using dma engine.

This patch introduces the same check we are performing in the simple
iovec copy case to the IOAT case as well. It fixes the indefinite
recvmsg(MSG_TRUNC) hangs.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
net: fix rtnetlink IFF_PROMISC and IFF_ALLMULTI handling 2012-08-19T17:15:25+00:00 Jiri Benc jbenc@redhat.com 2012-07-27T02:58:22+00:00 99517853a21edf2327cbe34441de9142720563c8 [ Upstream commit b1beb681cba5358f62e6187340660ade226a5fcc ] When device flags are set using rtnetlink, IFF_PROMISC and IFF_ALLMULTI flags are handled specially. Function dev_change_flags sets IFF_PROMISC and IFF_ALLMULTI bits in dev->gflags according to the passed value but do_setlink passes a result of rtnl_dev_combine_flags which takes those bits from dev->flags. This can be easily trigerred by doing: tcpdump -i eth0 & ip l s up eth0 ip sets IFF_UP flag in ifi_flags and ifi_change, which is combined with IFF_PROMISC by rtnl_dev_combine_flags, causing __dev_change_flags to set IFF_PROMISC in gflags. Reported-by: Max Matveev <makc@redhat.com> Signed-off-by: Jiri Benc <jbenc@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
[ Upstream commit b1beb681cba5358f62e6187340660ade226a5fcc ]

When device flags are set using rtnetlink, IFF_PROMISC and IFF_ALLMULTI
flags are handled specially. Function dev_change_flags sets IFF_PROMISC and
IFF_ALLMULTI bits in dev->gflags according to the passed value but
do_setlink passes a result of rtnl_dev_combine_flags which takes those bits
from dev->flags.

This can be easily trigerred by doing:

tcpdump -i eth0 &
ip l s up eth0

ip sets IFF_UP flag in ifi_flags and ifi_change, which is combined with
IFF_PROMISC by rtnl_dev_combine_flags, causing __dev_change_flags to set
IFF_PROMISC in gflags.

Reported-by: Max Matveev <makc@redhat.com>
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
tcp: Add TCP_USER_TIMEOUT negative value check 2012-08-19T17:15:24+00:00 Hangbin Liu liuhangbin@gmail.com 2012-07-26T22:52:21+00:00 df7ba2e6620095039c0aa42af7de1ec565eca2eb [ Upstream commit 42493570100b91ef663c4c6f0c0fdab238f9d3c2 ] TCP_USER_TIMEOUT is a TCP level socket option that takes an unsigned int. But patch "tcp: Add TCP_USER_TIMEOUT socket option"(dca43c75) didn't check the negative values. If a user assign -1 to it, the socket will set successfully and wait for 4294967295 miliseconds. This patch add a negative value check to avoid this issue. Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
[ Upstream commit 42493570100b91ef663c4c6f0c0fdab238f9d3c2 ]

TCP_USER_TIMEOUT is a TCP level socket option that takes an unsigned int. But
patch "tcp: Add TCP_USER_TIMEOUT socket option"(dca43c75) didn't check the negative
values. If a user assign -1 to it, the socket will set successfully and wait
for 4294967295 miliseconds. This patch add a negative value check to avoid
this issue.

Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
wanmain: comparing array with NULL 2012-08-19T17:15:24+00:00 Alan Cox alan@linux.intel.com 2012-07-24T08:16:25+00:00 761bfbd36cbff87f2d04502b66a363507a08ad33 [ Upstream commit 8b72ff6484fe303e01498b58621810a114f3cf09 ] gcc really should warn about these ! Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
[ Upstream commit 8b72ff6484fe303e01498b58621810a114f3cf09 ]

gcc really should warn about these !

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
cipso: don't follow a NULL pointer when setsockopt() is called 2012-08-19T17:15:23+00:00 Paul Moore pmoore@redhat.com 2012-07-17T11:07:47+00:00 7f6453d8c6f68e26fa6086c654b7fca39b960637 [ Upstream commit 89d7ae34cdda4195809a5a987f697a517a2a3177 ] As reported by Alan Cox, and verified by Lin Ming, when a user attempts to add a CIPSO option to a socket using the CIPSO_V4_TAG_LOCAL tag the kernel dies a terrible death when it attempts to follow a NULL pointer (the skb argument to cipso_v4_validate() is NULL when called via the setsockopt() syscall). This patch fixes this by first checking to ensure that the skb is non-NULL before using it to find the incoming network interface. In the unlikely case where the skb is NULL and the user attempts to add a CIPSO option with the _TAG_LOCAL tag we return an error as this is not something we want to allow. A simple reproducer, kindly supplied by Lin Ming, although you must have the CIPSO DOI #3 configure on the system first or you will be caught early in cipso_v4_validate(): #include <sys/types.h> #include <sys/socket.h> #include <linux/ip.h> #include <linux/in.h> #include <string.h> struct local_tag { char type; char length; char info[4]; }; struct cipso { char type; char length; char doi[4]; struct local_tag local; }; int main(int argc, char **argv) { int sockfd; struct cipso cipso = { .type = IPOPT_CIPSO, .length = sizeof(struct cipso), .local = { .type = 128, .length = sizeof(struct local_tag), }, }; memset(cipso.doi, 0, 4); cipso.doi[3] = 3; sockfd = socket(AF_INET, SOCK_DGRAM, 0); #define SOL_IP 0 setsockopt(sockfd, SOL_IP, IP_OPTIONS, &cipso, sizeof(struct cipso)); return 0; } CC: Lin Ming <mlin@ss.pku.edu.cn> Reported-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Paul Moore <pmoore@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
[ Upstream commit 89d7ae34cdda4195809a5a987f697a517a2a3177 ]

As reported by Alan Cox, and verified by Lin Ming, when a user
attempts to add a CIPSO option to a socket using the CIPSO_V4_TAG_LOCAL
tag the kernel dies a terrible death when it attempts to follow a NULL
pointer (the skb argument to cipso_v4_validate() is NULL when called via
the setsockopt() syscall).

This patch fixes this by first checking to ensure that the skb is
non-NULL before using it to find the incoming network interface.  In
the unlikely case where the skb is NULL and the user attempts to add
a CIPSO option with the _TAG_LOCAL tag we return an error as this is
not something we want to allow.

A simple reproducer, kindly supplied by Lin Ming, although you must
have the CIPSO DOI #3 configure on the system first or you will be
caught early in cipso_v4_validate():

	#include <sys/types.h>
	#include <sys/socket.h>
	#include <linux/ip.h>
	#include <linux/in.h>
	#include <string.h>

	struct local_tag {
		char type;
		char length;
		char info[4];
	};

	struct cipso {
		char type;
		char length;
		char doi[4];
		struct local_tag local;
	};

	int main(int argc, char **argv)
	{
		int sockfd;
		struct cipso cipso = {
			.type = IPOPT_CIPSO,
			.length = sizeof(struct cipso),
			.local = {
				.type = 128,
				.length = sizeof(struct local_tag),
			},
		};

		memset(cipso.doi, 0, 4);
		cipso.doi[3] = 3;

		sockfd = socket(AF_INET, SOCK_DGRAM, 0);
		#define SOL_IP 0
		setsockopt(sockfd, SOL_IP, IP_OPTIONS,
			&cipso, sizeof(struct cipso));

		return 0;
	}

CC: Lin Ming <mlin@ss.pku.edu.cn>
Reported-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Paul Moore <pmoore@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
caif: Fix access to freed pernet memory 2012-08-19T17:15:22+00:00 Sjur Brændeland sjur.brandeland@stericsson.com 2012-07-15T10:10:14+00:00 9fbc36b812a7f55972682b4b175d2284f487df77 [ Upstream commit 96f80d123eff05c3cd4701463786b87952a6c3ac ] unregister_netdevice_notifier() must be called before unregister_pernet_subsys() to avoid accessing already freed pernet memory. This fixes the following oops when doing rmmod: Call Trace: [<ffffffffa0f802bd>] caif_device_notify+0x4d/0x5a0 [caif] [<ffffffff81552ba9>] unregister_netdevice_notifier+0xb9/0x100 [<ffffffffa0f86dcc>] caif_device_exit+0x1c/0x250 [caif] [<ffffffff810e7734>] sys_delete_module+0x1a4/0x300 [<ffffffff810da82d>] ? trace_hardirqs_on_caller+0x15d/0x1e0 [<ffffffff813517de>] ? trace_hardirqs_on_thunk+0x3a/0x3 [<ffffffff81696bad>] system_call_fastpath+0x1a/0x1f RIP [<ffffffffa0f7f561>] caif_get+0x51/0xb0 [caif] Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
[ Upstream commit 96f80d123eff05c3cd4701463786b87952a6c3ac ]

unregister_netdevice_notifier() must be called before
unregister_pernet_subsys() to avoid accessing already freed
pernet memory. This fixes the following oops when doing rmmod:

Call Trace:
 [<ffffffffa0f802bd>] caif_device_notify+0x4d/0x5a0 [caif]
 [<ffffffff81552ba9>] unregister_netdevice_notifier+0xb9/0x100
 [<ffffffffa0f86dcc>] caif_device_exit+0x1c/0x250 [caif]
 [<ffffffff810e7734>] sys_delete_module+0x1a4/0x300
 [<ffffffff810da82d>] ? trace_hardirqs_on_caller+0x15d/0x1e0
 [<ffffffff813517de>] ? trace_hardirqs_on_thunk+0x3a/0x3
 [<ffffffff81696bad>] system_call_fastpath+0x1a/0x1f

RIP
 [<ffffffffa0f7f561>] caif_get+0x51/0xb0 [caif]

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
sctp: Fix list corruption resulting from freeing an association on a list 2012-08-19T17:15:22+00:00 Neil Horman nhorman@tuxdriver.com 2012-07-16T09:13:51+00:00 e44b8b47d096751cb15a81b4c0f83a05fc1f49c8 [ 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] <IRQ> [22766.387150] [<ffffffffa169f292>] ? __sctp_lookup_association+0x62/0xd0 [sctp] [22766.387154] [<ffffffffa169f2b6>] __sctp_lookup_association+0x86/0xd0 [sctp] [22766.387157] [<ffffffffa169f597>] sctp_rcv+0x207/0xbb0 [sctp] [22766.387161] [<ffffffff810d4da8>] ? trace_hardirqs_off_caller+0x28/0xd0 [22766.387163] [<ffffffff815827e3>] ? nf_hook_slow+0x133/0x210 [22766.387166] [<ffffffff815902fc>] ? ip_local_deliver_finish+0x4c/0x4c0 [22766.387168] [<ffffffff8159043d>] ip_local_deliver_finish+0x18d/0x4c0 [22766.387169] [<ffffffff815902fc>] ? ip_local_deliver_finish+0x4c/0x4c0 [22766.387171] [<ffffffff81590a07>] ip_local_deliver+0x47/0x80 [22766.387172] [<ffffffff8158fd80>] ip_rcv_finish+0x150/0x680 [22766.387174] [<ffffffff81590c54>] ip_rcv+0x214/0x320 [22766.387176] [<ffffffff81558c07>] __netif_receive_skb+0x7b7/0x910 [22766.387178] [<ffffffff8155856c>] ? __netif_receive_skb+0x11c/0x910 [22766.387180] [<ffffffff810d423e>] ? put_lock_stats.isra.25+0xe/0x40 [22766.387182] [<ffffffff81558f83>] netif_receive_skb+0x23/0x1f0 [22766.387183] [<ffffffff815596a9>] ? dev_gro_receive+0x139/0x440 [22766.387185] [<ffffffff81559280>] napi_skb_finish+0x70/0xa0 [22766.387187] [<ffffffff81559cb5>] napi_gro_receive+0xf5/0x130 [22766.387218] [<ffffffffa01c4679>] e1000_receive_skb+0x59/0x70 [e1000e] [22766.387242] [<ffffffffa01c5aab>] e1000_clean_rx_irq+0x28b/0x460 [e1000e] [22766.387266] [<ffffffffa01c9c18>] e1000e_poll+0x78/0x430 [e1000e] [22766.387268] [<ffffffff81559fea>] net_rx_action+0x1aa/0x3d0 [22766.387270] [<ffffffff810a495f>] ? account_system_vtime+0x10f/0x130 [22766.387273] [<ffffffff810734d0>] __do_softirq+0xe0/0x420 [22766.387275] [<ffffffff8169826c>] call_softirq+0x1c/0x30 [22766.387278] [<ffffffff8101db15>] do_softirq+0xd5/0x110 [22766.387279] [<ffffffff81073bc5>] irq_exit+0xd5/0xe0 [22766.387281] [<ffffffff81698b03>] do_IRQ+0x63/0xd0 [22766.387283] [<ffffffff8168ee2f>] common_interrupt+0x6f/0x6f [22766.387283] <EOI> [22766.387284] [22766.387285] [<ffffffff8168eed9>] ? 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] [<ffffffffa168a2c9>] sctp_assoc_is_match+0x19/0x90 [sctp] [22766.387311] RSP <ffff880147c039b0> [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 <nhorman@tuxdriver.com> Reported-by: davej@redhat.com CC: davej@redhat.com CC: "David S. Miller" <davem@davemloft.net> CC: Vlad Yasevich <vyasevich@gmail.com> CC: Sridhar Samudrala <sri@us.ibm.com> CC: linux-sctp@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
[ 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]  <IRQ>
[22766.387150]  [<ffffffffa169f292>] ? __sctp_lookup_association+0x62/0xd0
[sctp]
[22766.387154]  [<ffffffffa169f2b6>] __sctp_lookup_association+0x86/0xd0 [sctp]
[22766.387157]  [<ffffffffa169f597>] sctp_rcv+0x207/0xbb0 [sctp]
[22766.387161]  [<ffffffff810d4da8>] ? trace_hardirqs_off_caller+0x28/0xd0
[22766.387163]  [<ffffffff815827e3>] ? nf_hook_slow+0x133/0x210
[22766.387166]  [<ffffffff815902fc>] ? ip_local_deliver_finish+0x4c/0x4c0
[22766.387168]  [<ffffffff8159043d>] ip_local_deliver_finish+0x18d/0x4c0
[22766.387169]  [<ffffffff815902fc>] ? ip_local_deliver_finish+0x4c/0x4c0
[22766.387171]  [<ffffffff81590a07>] ip_local_deliver+0x47/0x80
[22766.387172]  [<ffffffff8158fd80>] ip_rcv_finish+0x150/0x680
[22766.387174]  [<ffffffff81590c54>] ip_rcv+0x214/0x320
[22766.387176]  [<ffffffff81558c07>] __netif_receive_skb+0x7b7/0x910
[22766.387178]  [<ffffffff8155856c>] ? __netif_receive_skb+0x11c/0x910
[22766.387180]  [<ffffffff810d423e>] ? put_lock_stats.isra.25+0xe/0x40
[22766.387182]  [<ffffffff81558f83>] netif_receive_skb+0x23/0x1f0
[22766.387183]  [<ffffffff815596a9>] ? dev_gro_receive+0x139/0x440
[22766.387185]  [<ffffffff81559280>] napi_skb_finish+0x70/0xa0
[22766.387187]  [<ffffffff81559cb5>] napi_gro_receive+0xf5/0x130
[22766.387218]  [<ffffffffa01c4679>] e1000_receive_skb+0x59/0x70 [e1000e]
[22766.387242]  [<ffffffffa01c5aab>] e1000_clean_rx_irq+0x28b/0x460 [e1000e]
[22766.387266]  [<ffffffffa01c9c18>] e1000e_poll+0x78/0x430 [e1000e]
[22766.387268]  [<ffffffff81559fea>] net_rx_action+0x1aa/0x3d0
[22766.387270]  [<ffffffff810a495f>] ? account_system_vtime+0x10f/0x130
[22766.387273]  [<ffffffff810734d0>] __do_softirq+0xe0/0x420
[22766.387275]  [<ffffffff8169826c>] call_softirq+0x1c/0x30
[22766.387278]  [<ffffffff8101db15>] do_softirq+0xd5/0x110
[22766.387279]  [<ffffffff81073bc5>] irq_exit+0xd5/0xe0
[22766.387281]  [<ffffffff81698b03>] do_IRQ+0x63/0xd0
[22766.387283]  [<ffffffff8168ee2f>] common_interrupt+0x6f/0x6f
[22766.387283]  <EOI>
[22766.387284]
[22766.387285]  [<ffffffff8168eed9>] ? 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]  [<ffffffffa168a2c9>] sctp_assoc_is_match+0x19/0x90 [sctp]
[22766.387311]  RSP <ffff880147c039b0>
[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 <nhorman@tuxdriver.com>
Reported-by: davej@redhat.com
CC: davej@redhat.com
CC: "David S. Miller" <davem@davemloft.net>
CC: Vlad Yasevich <vyasevich@gmail.com>
CC: Sridhar Samudrala <sri@us.ibm.com>
CC: linux-sctp@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
sch_sfb: Fix missing NULL check 2012-08-19T17:15:21+00:00 Alan Cox alan@linux.intel.com 2012-07-12T03:39:11+00:00 ab12cbb527ec1afc9f71bd2331164c375e1e68f7 [ Upstream commit 7ac2908e4b2edaec60e9090ddb4d9ceb76c05e7d ] Resolves-bug: https://bugzilla.kernel.org/show_bug.cgi?id=44461 Signed-off-by: Alan Cox <alan@linux.intel.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
[ Upstream commit 7ac2908e4b2edaec60e9090ddb4d9ceb76c05e7d ]

Resolves-bug: https://bugzilla.kernel.org/show_bug.cgi?id=44461

Signed-off-by: Alan Cox <alan@linux.intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>