linux-stable.git/net/tipc, branch v4.4.64 Linux kernel stable tree tipc: fix crash during node removal 2017-04-27T07:09:34+00:00 Jon Paul Maloy jon.maloy@ericsson.com 2016-02-24T16:10:48+00:00 6862fa9077dea0ec2ba5e6ea7c7f90b786288596 commit d25a01257e422a4bdeb426f69529d57c73b235fe upstream. When the TIPC module is unloaded, we have identified a race condition that allows a node reference counter to go to zero and the node instance being freed before the node timer is finished with accessing it. This leads to occasional crashes, especially in multi-namespace environments. The scenario goes as follows: CPU0:(node_stop) CPU1:(node_timeout) // ref == 2 1: if(!mod_timer()) 2: if (del_timer()) 3: tipc_node_put() // ref -> 1 4: tipc_node_put() // ref -> 0 5: kfree_rcu(node); 6: tipc_node_get(node) 7: // BOOM! We now clean up this functionality as follows: 1) We remove the node pointer from the node lookup table before we attempt deactivating the timer. This way, we reduce the risk that tipc_node_find() may obtain a valid pointer to an instance marked for deletion; a harmless but undesirable situation. 2) We use del_timer_sync() instead of del_timer() to safely deactivate the node timer without any risk that it might be reactivated by the timeout handler. There is no risk of deadlock here, since the two functions never touch the same spinlocks. 3: We remove a pointless tipc_node_get() + tipc_node_put() from the timeout handler. Reported-by: Zhijiang Hu <huzhijiang@gmail.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit d25a01257e422a4bdeb426f69529d57c73b235fe upstream.

When the TIPC module is unloaded, we have identified a race condition
that allows a node reference counter to go to zero and the node instance
being freed before the node timer is finished with accessing it. This
leads to occasional crashes, especially in multi-namespace environments.

The scenario goes as follows:

CPU0:(node_stop)                       CPU1:(node_timeout)  // ref == 2

1:                                          if(!mod_timer())
2: if (del_timer())
3:   tipc_node_put()                                        // ref -> 1
4: tipc_node_put()                                          // ref -> 0
5:   kfree_rcu(node);
6:                                               tipc_node_get(node)
7:                                               // BOOM!

We now clean up this functionality as follows:

1) We remove the node pointer from the node lookup table before we
   attempt deactivating the timer. This way, we reduce the risk that
   tipc_node_find() may obtain a valid pointer to an instance marked
   for deletion; a harmless but undesirable situation.

2) We use del_timer_sync() instead of del_timer() to safely deactivate
   the node timer without any risk that it might be reactivated by the
   timeout handler. There is no risk of deadlock here, since the two
   functions never touch the same spinlocks.

3: We remove a pointless tipc_node_get() + tipc_node_put() from the
   timeout handler.

Reported-by: Zhijiang Hu <huzhijiang@gmail.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tipc: fix NULL pointer dereference in shutdown() 2016-09-30T08:18:36+00:00 Vegard Nossum vegard.nossum@oracle.com 2016-07-23T06:15:04+00:00 4be4511af7966b7b0f93d9f129a876458794f2f3 [ Upstream commit d2fbdf76b85bcdfe57b8ef2ba09d20e8ada79abd ] tipc_msg_create() can return a NULL skb and if so, we shouldn't try to call tipc_node_xmit_skb() on it. general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 3 PID: 30298 Comm: trinity-c0 Not tainted 4.7.0-rc7+ #19 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 task: ffff8800baf09980 ti: ffff8800595b8000 task.ti: ffff8800595b8000 RIP: 0010:[<ffffffff830bb46b>] [<ffffffff830bb46b>] tipc_node_xmit_skb+0x6b/0x140 RSP: 0018:ffff8800595bfce8 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000000003023b0e0 RDX: 0000000000000000 RSI: dffffc0000000000 RDI: ffffffff83d12580 RBP: ffff8800595bfd78 R08: ffffed000b2b7f32 R09: 0000000000000000 R10: fffffbfff0759725 R11: 0000000000000000 R12: 1ffff1000b2b7f9f R13: ffff8800595bfd58 R14: ffffffff83d12580 R15: dffffc0000000000 FS: 00007fcdde242700(0000) GS:ffff88011af80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fcddde1db10 CR3: 000000006874b000 CR4: 00000000000006e0 DR0: 00007fcdde248000 DR1: 00007fcddd73d000 DR2: 00007fcdde248000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000090602 Stack: 0000000000000018 0000000000000018 0000000041b58ab3 ffffffff83954208 ffffffff830bb400 ffff8800595bfd30 ffffffff8309d767 0000000000000018 0000000000000018 ffff8800595bfd78 ffffffff8309da1a 00000000810ee611 Call Trace: [<ffffffff830c84a3>] tipc_shutdown+0x553/0x880 [<ffffffff825b4a3b>] SyS_shutdown+0x14b/0x170 [<ffffffff8100334c>] do_syscall_64+0x19c/0x410 [<ffffffff83295ca5>] entry_SYSCALL64_slow_path+0x25/0x25 Code: 90 00 b4 0b 83 c7 00 f1 f1 f1 f1 4c 8d 6d e0 c7 40 04 00 00 00 f4 c7 40 08 f3 f3 f3 f3 48 89 d8 48 c1 e8 03 c7 45 b4 00 00 00 00 <80> 3c 30 00 75 78 48 8d 7b 08 49 8d 75 c0 48 b8 00 00 00 00 00 RIP [<ffffffff830bb46b>] tipc_node_xmit_skb+0x6b/0x140 RSP <ffff8800595bfce8> ---[ end trace 57b0484e351e71f1 ]--- I feel like we should maybe return -ENOMEM or -ENOBUFS, but I'm not sure userspace is equipped to handle that. Anyway, this is better than a GPF and looks somewhat consistent with other tipc_msg_create() callers. Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Acked-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit d2fbdf76b85bcdfe57b8ef2ba09d20e8ada79abd ]

tipc_msg_create() can return a NULL skb and if so, we shouldn't try to
call tipc_node_xmit_skb() on it.

    general protection fault: 0000 [#1] PREEMPT SMP KASAN
    CPU: 3 PID: 30298 Comm: trinity-c0 Not tainted 4.7.0-rc7+ #19
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
    task: ffff8800baf09980 ti: ffff8800595b8000 task.ti: ffff8800595b8000
    RIP: 0010:[<ffffffff830bb46b>]  [<ffffffff830bb46b>] tipc_node_xmit_skb+0x6b/0x140
    RSP: 0018:ffff8800595bfce8  EFLAGS: 00010246
    RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000000003023b0e0
    RDX: 0000000000000000 RSI: dffffc0000000000 RDI: ffffffff83d12580
    RBP: ffff8800595bfd78 R08: ffffed000b2b7f32 R09: 0000000000000000
    R10: fffffbfff0759725 R11: 0000000000000000 R12: 1ffff1000b2b7f9f
    R13: ffff8800595bfd58 R14: ffffffff83d12580 R15: dffffc0000000000
    FS:  00007fcdde242700(0000) GS:ffff88011af80000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 00007fcddde1db10 CR3: 000000006874b000 CR4: 00000000000006e0
    DR0: 00007fcdde248000 DR1: 00007fcddd73d000 DR2: 00007fcdde248000
    DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000090602
    Stack:
     0000000000000018 0000000000000018 0000000041b58ab3 ffffffff83954208
     ffffffff830bb400 ffff8800595bfd30 ffffffff8309d767 0000000000000018
     0000000000000018 ffff8800595bfd78 ffffffff8309da1a 00000000810ee611
    Call Trace:
     [<ffffffff830c84a3>] tipc_shutdown+0x553/0x880
     [<ffffffff825b4a3b>] SyS_shutdown+0x14b/0x170
     [<ffffffff8100334c>] do_syscall_64+0x19c/0x410
     [<ffffffff83295ca5>] entry_SYSCALL64_slow_path+0x25/0x25
    Code: 90 00 b4 0b 83 c7 00 f1 f1 f1 f1 4c 8d 6d e0 c7 40 04 00 00 00 f4 c7 40 08 f3 f3 f3 f3 48 89 d8 48 c1 e8 03 c7 45 b4 00 00 00 00 <80> 3c 30 00 75 78 48 8d 7b 08 49 8d 75 c0 48 b8 00 00 00 00 00
    RIP  [<ffffffff830bb46b>] tipc_node_xmit_skb+0x6b/0x140
     RSP <ffff8800595bfce8>
    ---[ end trace 57b0484e351e71f1 ]---

I feel like we should maybe return -ENOMEM or -ENOBUFS, but I'm not sure
userspace is equipped to handle that. Anyway, this is better than a GPF
and looks somewhat consistent with other tipc_msg_create() callers.

Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tipc: move linearization of buffers to generic code 2016-09-24T08:07:35+00:00 Jon Paul Maloy jon.maloy@ericsson.com 2016-09-21T13:00:02+00:00 e70bb22b8fc502757332d06a484696ce3efa9d2a commit c7cad0d6f70cd4ce8644ffe528a4df1cdc2e77f5 upstream. In commit 5cbb28a4bf65c7e4 ("tipc: linearize arriving NAME_DISTR and LINK_PROTO buffers") we added linearization of NAME_DISTRIBUTOR, LINK_PROTOCOL/RESET and LINK_PROTOCOL/ACTIVATE to the function tipc_udp_recv(). The location of the change was selected in order to make the commit easily appliable to 'net' and 'stable'. We now move this linearization to where it should be done, in the functions tipc_named_rcv() and tipc_link_proto_rcv() respectively. Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Juerg Haefliger <juerg.haefliger@hpe.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit c7cad0d6f70cd4ce8644ffe528a4df1cdc2e77f5 upstream.

In commit 5cbb28a4bf65c7e4 ("tipc: linearize arriving NAME_DISTR
and LINK_PROTO buffers") we added linearization of NAME_DISTRIBUTOR,
LINK_PROTOCOL/RESET and LINK_PROTOCOL/ACTIVATE to the function
tipc_udp_recv(). The location of the change was selected in order
to make the commit easily appliable to 'net' and 'stable'.

We now move this linearization to where it should be done, in the
functions tipc_named_rcv() and tipc_link_proto_rcv() respectively.

Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Juerg Haefliger <juerg.haefliger@hpe.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tipc: fix nl compat regression for link statistics 2016-09-15T06:27:49+00:00 Richard Alpe richard.alpe@ericsson.com 2016-07-14T14:02:07+00:00 8b2e345ed50bc140e2334e6b8fa9108ee66683cb [ Upstream commit 55e77a3e8297581c919b45adcc4d0815b69afa84 ] Fix incorrect use of nla_strlcpy() where the first NLA_HDRLEN bytes of the link name where left out. Making the output of tipc-config -ls look something like: Link statistics: dcast-link 1:data0-1.1.2:data0 1:data0-1.1.3:data0 Also, for the record, the patch that introduce this regression claims "Sending the whole object out can cause a leak". Which isn't very likely as this is a compat layer, where the data we are parsing is generated by us and we know the string to be NULL terminated. But you can of course never be to secure. Fixes: 5d2be1422e02 (tipc: fix an infoleak in tipc_nl_compat_link_dump) Signed-off-by: Richard Alpe <richard.alpe@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 55e77a3e8297581c919b45adcc4d0815b69afa84 ]

Fix incorrect use of nla_strlcpy() where the first NLA_HDRLEN bytes
of the link name where left out.

Making the output of tipc-config -ls look something like:
Link statistics:
dcast-link
1:data0-1.1.2:data0
1:data0-1.1.3:data0

Also, for the record, the patch that introduce this regression
claims "Sending the whole object out can cause a leak". Which isn't
very likely as this is a compat layer, where the data we are parsing
is generated by us and we know the string to be NULL terminated. But
you can of course never be to secure.

Fixes: 5d2be1422e02 (tipc: fix an infoleak in tipc_nl_compat_link_dump)
Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tipc: fix an infoleak in tipc_nl_compat_link_dump 2016-09-15T06:27:49+00:00 Kangjie Lu kangjielu@gmail.com 2016-07-14T14:02:06+00:00 5fb71611925f734f7fe03a45527e14b296fd5167 [ Upstream commit 5d2be1422e02ccd697ccfcd45c85b4a26e6178e2 ] link_info.str is a char array of size 60. Memory after the NULL byte is not initialized. Sending the whole object out can cause a leak. Signed-off-by: Kangjie Lu <kjlu@gatech.edu> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 5d2be1422e02ccd697ccfcd45c85b4a26e6178e2 ]

link_info.str is a char array of size 60. Memory after the NULL
byte is not initialized. Sending the whole object out can cause
a leak.

Signed-off-by: Kangjie Lu <kjlu@gatech.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tipc: fix nullptr crash during subscription cancel 2016-09-15T06:27:44+00:00 Parthasarathy Bhuvaragan parthasarathy.bhuvaragan@ericsson.com 2016-03-03T16:54:54+00:00 1b82da380dcfd030bd1ee32853b132659bb0ab4c [ Upstream commit 4de13d7ed6ffdcbb34317acaa9236f121176f5f8 ] commit 4d5cfcba2f6e ('tipc: fix connection abort during subscription cancel'), removes the check for a valid subscription before calling tipc_nametbl_subscribe(). This will lead to a nullptr exception when we process a subscription cancel request. For a cancel request, a null subscription is passed to tipc_nametbl_subscribe() resulting in exception. In this commit, we call tipc_nametbl_subscribe() only for a valid subscription. Fixes: 4d5cfcba2f6e ('tipc: fix connection abort during subscription cancel') Reported-by: Anders Widell <anders.widell@ericsson.com> Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 4de13d7ed6ffdcbb34317acaa9236f121176f5f8 ]

commit 4d5cfcba2f6e ('tipc: fix connection abort during subscription
cancel'), removes the check for a valid subscription before calling
tipc_nametbl_subscribe().

This will lead to a nullptr exception when we process a
subscription cancel request. For a cancel request, a null
subscription is passed to tipc_nametbl_subscribe() resulting
in exception.

In this commit, we call tipc_nametbl_subscribe() only for
a valid subscription.

Fixes: 4d5cfcba2f6e ('tipc: fix connection abort during subscription cancel')
Reported-by: Anders Widell <anders.widell@ericsson.com>
Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tipc: fix nametable publication field in nl compat 2016-06-24T17:18:16+00:00 Richard Alpe richard.alpe@ericsson.com 2016-05-17T14:57:37+00:00 6a58f3e12e8e5c330940b38cc8c98d52171aefa8 [ Upstream commit 03aaaa9b941e136757b55c4cf775aab6068dfd94 ] The publication field of the old netlink API should contain the publication key and not the publication reference. Fixes: 44a8ae94fd55 (tipc: convert legacy nl name table dump to nl compat) Signed-off-by: Richard Alpe <richard.alpe@ericsson.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 03aaaa9b941e136757b55c4cf775aab6068dfd94 ]

The publication field of the old netlink API should contain the
publication key and not the publication reference.

Fixes: 44a8ae94fd55 (tipc: convert legacy nl name table dump to nl compat)
Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tipc: check nl sock before parsing nested attributes 2016-06-24T17:18:16+00:00 Richard Alpe richard.alpe@ericsson.com 2016-05-16T09:14:54+00:00 23cdd8c3cbe9d790f23d7f9ae14e9b828f56f69c [ Upstream commit 45e093ae2830cd1264677d47ff9a95a71f5d9f9c ] Make sure the socket for which the user is listing publication exists before parsing the socket netlink attributes. Prior to this patch a call without any socket caused a NULL pointer dereference in tipc_nl_publ_dump(). Tested-and-reported-by: Baozeng Ding <sploving1@gmail.com> Signed-off-by: Richard Alpe <richard.alpe@ericsson.com> Acked-by: Jon Maloy <jon.maloy@ericsson.cm> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 45e093ae2830cd1264677d47ff9a95a71f5d9f9c ]

Make sure the socket for which the user is listing publication exists
before parsing the socket netlink attributes.

Prior to this patch a call without any socket caused a NULL pointer
dereference in tipc_nl_publ_dump().

Tested-and-reported-by: Baozeng Ding <sploving1@gmail.com>
Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.cm>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tipc: Revert "tipc: use existing sk_write_queue for outgoing packet chain" 2016-04-20T06:41:58+00:00 Parthasarathy Bhuvaragan parthasarathy.bhuvaragan@ericsson.com 2016-03-01T10:07:09+00:00 7da899cee1f19bdaf2649e5e8c36c0e65ace5a5c [ Upstream commit f214fc402967e1bc94ad7f39faa03db5813d6849 ] reverts commit 94153e36e709e ("tipc: use existing sk_write_queue for outgoing packet chain") In Commit 94153e36e709e, we assume that we fill & empty the socket's sk_write_queue within the same lock_sock() session. This is not true if the link is congested. During congestion, the socket lock is released while we wait for the congestion to cease. This implementation causes a nullptr exception, if the user space program has several threads accessing the same socket descriptor. Consider two threads of the same program performing the following: Thread1 Thread2 -------------------- ---------------------- Enter tipc_sendmsg() Enter tipc_sendmsg() lock_sock() lock_sock() Enter tipc_link_xmit(), ret=ELINKCONG spin on socket lock.. sk_wait_event() : release_sock() grab socket lock : Enter tipc_link_xmit(), ret=0 : release_sock() Wakeup after congestion lock_sock() skb = skb_peek(pktchain); !! TIPC_SKB_CB(skb)->wakeup_pending = tsk->link_cong; In this case, the second thread transmits the buffers belonging to both thread1 and thread2 successfully. When the first thread wakeup after the congestion it assumes that the pktchain is intact and operates on the skb's in it, which leads to the following exception: [2102.439969] BUG: unable to handle kernel NULL pointer dereference at 00000000000000d0 [2102.440074] IP: [<ffffffffa005f330>] __tipc_link_xmit+0x2b0/0x4d0 [tipc] [2102.440074] PGD 3fa3f067 PUD 3fa6b067 PMD 0 [2102.440074] Oops: 0000 [#1] SMP [2102.440074] CPU: 2 PID: 244 Comm: sender Not tainted 3.12.28 #1 [2102.440074] RIP: 0010:[<ffffffffa005f330>] [<ffffffffa005f330>] __tipc_link_xmit+0x2b0/0x4d0 [tipc] [...] [2102.440074] Call Trace: [2102.440074] [<ffffffff8163f0b9>] ? schedule+0x29/0x70 [2102.440074] [<ffffffffa006a756>] ? tipc_node_unlock+0x46/0x170 [tipc] [2102.440074] [<ffffffffa005f761>] tipc_link_xmit+0x51/0xf0 [tipc] [2102.440074] [<ffffffffa006d8ae>] tipc_send_stream+0x11e/0x4f0 [tipc] [2102.440074] [<ffffffff8106b150>] ? __wake_up_sync+0x20/0x20 [2102.440074] [<ffffffffa006dc9c>] tipc_send_packet+0x1c/0x20 [tipc] [2102.440074] [<ffffffff81502478>] sock_sendmsg+0xa8/0xd0 [2102.440074] [<ffffffff81507895>] ? release_sock+0x145/0x170 [2102.440074] [<ffffffff815030d8>] ___sys_sendmsg+0x3d8/0x3e0 [2102.440074] [<ffffffff816426ae>] ? _raw_spin_unlock+0xe/0x10 [2102.440074] [<ffffffff81115c2a>] ? handle_mm_fault+0x6ca/0x9d0 [2102.440074] [<ffffffff8107dd65>] ? set_next_entity+0x85/0xa0 [2102.440074] [<ffffffff816426de>] ? _raw_spin_unlock_irq+0xe/0x20 [2102.440074] [<ffffffff8107463c>] ? finish_task_switch+0x5c/0xc0 [2102.440074] [<ffffffff8163ea8c>] ? __schedule+0x34c/0x950 [2102.440074] [<ffffffff81504e12>] __sys_sendmsg+0x42/0x80 [2102.440074] [<ffffffff81504e62>] SyS_sendmsg+0x12/0x20 [2102.440074] [<ffffffff8164aed2>] system_call_fastpath+0x16/0x1b In this commit, we maintain the skb list always in the stack. Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit f214fc402967e1bc94ad7f39faa03db5813d6849 ]

reverts commit 94153e36e709e ("tipc: use existing sk_write_queue for
outgoing packet chain")

In Commit 94153e36e709e, we assume that we fill & empty the socket's
sk_write_queue within the same lock_sock() session.

This is not true if the link is congested. During congestion, the
socket lock is released while we wait for the congestion to cease.
This implementation causes a nullptr exception, if the user space
program has several threads accessing the same socket descriptor.

Consider two threads of the same program performing the following:
     Thread1                                  Thread2
--------------------                    ----------------------
Enter tipc_sendmsg()                    Enter tipc_sendmsg()
lock_sock()                             lock_sock()
Enter tipc_link_xmit(), ret=ELINKCONG   spin on socket lock..
sk_wait_event()                             :
release_sock()                          grab socket lock
    :                                   Enter tipc_link_xmit(), ret=0
    :                                   release_sock()
Wakeup after congestion
lock_sock()
skb = skb_peek(pktchain);
!! TIPC_SKB_CB(skb)->wakeup_pending = tsk->link_cong;

In this case, the second thread transmits the buffers belonging to
both thread1 and thread2 successfully. When the first thread wakeup
after the congestion it assumes that the pktchain is intact and
operates on the skb's in it, which leads to the following exception:

[2102.439969] BUG: unable to handle kernel NULL pointer dereference at 00000000000000d0
[2102.440074] IP: [<ffffffffa005f330>] __tipc_link_xmit+0x2b0/0x4d0 [tipc]
[2102.440074] PGD 3fa3f067 PUD 3fa6b067 PMD 0
[2102.440074] Oops: 0000 [#1] SMP
[2102.440074] CPU: 2 PID: 244 Comm: sender Not tainted 3.12.28 #1
[2102.440074] RIP: 0010:[<ffffffffa005f330>]  [<ffffffffa005f330>] __tipc_link_xmit+0x2b0/0x4d0 [tipc]
[...]
[2102.440074] Call Trace:
[2102.440074]  [<ffffffff8163f0b9>] ? schedule+0x29/0x70
[2102.440074]  [<ffffffffa006a756>] ? tipc_node_unlock+0x46/0x170 [tipc]
[2102.440074]  [<ffffffffa005f761>] tipc_link_xmit+0x51/0xf0 [tipc]
[2102.440074]  [<ffffffffa006d8ae>] tipc_send_stream+0x11e/0x4f0 [tipc]
[2102.440074]  [<ffffffff8106b150>] ? __wake_up_sync+0x20/0x20
[2102.440074]  [<ffffffffa006dc9c>] tipc_send_packet+0x1c/0x20 [tipc]
[2102.440074]  [<ffffffff81502478>] sock_sendmsg+0xa8/0xd0
[2102.440074]  [<ffffffff81507895>] ? release_sock+0x145/0x170
[2102.440074]  [<ffffffff815030d8>] ___sys_sendmsg+0x3d8/0x3e0
[2102.440074]  [<ffffffff816426ae>] ? _raw_spin_unlock+0xe/0x10
[2102.440074]  [<ffffffff81115c2a>] ? handle_mm_fault+0x6ca/0x9d0
[2102.440074]  [<ffffffff8107dd65>] ? set_next_entity+0x85/0xa0
[2102.440074]  [<ffffffff816426de>] ? _raw_spin_unlock_irq+0xe/0x20
[2102.440074]  [<ffffffff8107463c>] ? finish_task_switch+0x5c/0xc0
[2102.440074]  [<ffffffff8163ea8c>] ? __schedule+0x34c/0x950
[2102.440074]  [<ffffffff81504e12>] __sys_sendmsg+0x42/0x80
[2102.440074]  [<ffffffff81504e62>] SyS_sendmsg+0x12/0x20
[2102.440074]  [<ffffffff8164aed2>] system_call_fastpath+0x16/0x1b

In this commit, we maintain the skb list always in the stack.

Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tipc: unlock in error path 2016-03-03T23:07:07+00:00 Insu Yun wuninsu@gmail.com 2016-02-17T16:47:35+00:00 4ac39c3e2c80000a40b11bde33f425a44f1ef55b [ Upstream commit b53ce3e7d407aa4196877a48b8601181162ab158 ] tipc_bcast_unlock need to be unlocked in error path. Signed-off-by: Insu Yun <wuninsu@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit b53ce3e7d407aa4196877a48b8601181162ab158 ]

tipc_bcast_unlock need to be unlocked in error path.

Signed-off-by: Insu Yun <wuninsu@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>