linux-stable.git/net/l2tp, branch v3.10.78 Linux kernel stable tree l2tp: fix race while getting PMTU on PPP pseudo-wire 2014-10-15T06:31:57+00:00 Guillaume Nault g.nault@alphalink.fr 2014-09-03T12:12:55+00:00 696c5d5f340f57bf1085bc7cc95937d2349988cb [ Upstream commit eed4d839b0cdf9d84b0a9bc63de90fd5e1e886fb ] Use dst_entry held by sk_dst_get() to retrieve tunnel's PMTU. The dst_mtu(__sk_dst_get(tunnel->sock)) call was racy. __sk_dst_get() could return NULL if tunnel->sock->sk_dst_cache was reset just before the call, thus making dst_mtu() dereference a NULL pointer: [ 1937.661598] BUG: unable to handle kernel NULL pointer dereference at 0000000000000020 [ 1937.664005] IP: [<ffffffffa049db88>] pppol2tp_connect+0x33d/0x41e [l2tp_ppp] [ 1937.664005] PGD daf0c067 PUD d9f93067 PMD 0 [ 1937.664005] Oops: 0000 [#1] SMP [ 1937.664005] Modules linked in: l2tp_ppp l2tp_netlink l2tp_core ip6table_filter ip6_tables iptable_filter ip_tables ebtable_nat ebtables x_tables udp_tunnel pppoe pppox ppp_generic slhc deflate ctr twofish_generic twofish_x86_64_3way xts lrw gf128mul glue_helper twofish_x86_64 twofish_common blowfish_generic blowfish_x86_64 blowfish_common des_generic cbc xcbc rmd160 sha512_generic hmac crypto_null af_key xfrm_algo 8021q garp bridge stp llc tun atmtcp clip atm ext3 mbcache jbd iTCO_wdt coretemp kvm_intel iTCO_vendor_support kvm pcspkr evdev ehci_pci lpc_ich mfd_core i5400_edac edac_core i5k_amb shpchp button processor thermal_sys xfs crc32c_generic libcrc32c dm_mod usbhid sg hid sr_mod sd_mod cdrom crc_t10dif crct10dif_common ata_generic ahci ata_piix tg3 libahci libata uhci_hcd ptp ehci_hcd pps_core usbcore scsi_mod libphy usb_common [last unloaded: l2tp_core] [ 1937.664005] CPU: 0 PID: 10022 Comm: l2tpstress Tainted: G O 3.17.0-rc1 #1 [ 1937.664005] Hardware name: HP ProLiant DL160 G5, BIOS O12 08/22/2008 [ 1937.664005] task: ffff8800d8fda790 ti: ffff8800c43c4000 task.ti: ffff8800c43c4000 [ 1937.664005] RIP: 0010:[<ffffffffa049db88>] [<ffffffffa049db88>] pppol2tp_connect+0x33d/0x41e [l2tp_ppp] [ 1937.664005] RSP: 0018:ffff8800c43c7de8 EFLAGS: 00010282 [ 1937.664005] RAX: ffff8800da8a7240 RBX: ffff8800d8c64600 RCX: 000001c325a137b5 [ 1937.664005] RDX: 8c6318c6318c6320 RSI: 000000000000010c RDI: 0000000000000000 [ 1937.664005] RBP: ffff8800c43c7ea8 R08: 0000000000000000 R09: 0000000000000000 [ 1937.664005] R10: ffffffffa048e2c0 R11: ffff8800d8c64600 R12: ffff8800ca7a5000 [ 1937.664005] R13: ffff8800c439bf40 R14: 000000000000000c R15: 0000000000000009 [ 1937.664005] FS: 00007fd7f610f700(0000) GS:ffff88011a600000(0000) knlGS:0000000000000000 [ 1937.664005] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 1937.664005] CR2: 0000000000000020 CR3: 00000000d9d75000 CR4: 00000000000027e0 [ 1937.664005] Stack: [ 1937.664005] ffffffffa049da80 ffff8800d8fda790 000000000000005b ffff880000000009 [ 1937.664005] ffff8800daf3f200 0000000000000003 ffff8800c43c7e48 ffffffff81109b57 [ 1937.664005] ffffffff81109b0e ffffffff8114c566 0000000000000000 0000000000000000 [ 1937.664005] Call Trace: [ 1937.664005] [<ffffffffa049da80>] ? pppol2tp_connect+0x235/0x41e [l2tp_ppp] [ 1937.664005] [<ffffffff81109b57>] ? might_fault+0x9e/0xa5 [ 1937.664005] [<ffffffff81109b0e>] ? might_fault+0x55/0xa5 [ 1937.664005] [<ffffffff8114c566>] ? rcu_read_unlock+0x1c/0x26 [ 1937.664005] [<ffffffff81309196>] SYSC_connect+0x87/0xb1 [ 1937.664005] [<ffffffff813e56f7>] ? sysret_check+0x1b/0x56 [ 1937.664005] [<ffffffff8107590d>] ? trace_hardirqs_on_caller+0x145/0x1a1 [ 1937.664005] [<ffffffff81213dee>] ? trace_hardirqs_on_thunk+0x3a/0x3f [ 1937.664005] [<ffffffff8114c262>] ? spin_lock+0x9/0xb [ 1937.664005] [<ffffffff813092b4>] SyS_connect+0x9/0xb [ 1937.664005] [<ffffffff813e56d2>] system_call_fastpath+0x16/0x1b [ 1937.664005] Code: 10 2a 84 81 e8 65 76 bd e0 65 ff 0c 25 10 bb 00 00 4d 85 ed 74 37 48 8b 85 60 ff ff ff 48 8b 80 88 01 00 00 48 8b b8 10 02 00 00 <48> 8b 47 20 ff 50 20 85 c0 74 0f 83 e8 28 89 83 10 01 00 00 89 [ 1937.664005] RIP [<ffffffffa049db88>] pppol2tp_connect+0x33d/0x41e [l2tp_ppp] [ 1937.664005] RSP <ffff8800c43c7de8> [ 1937.664005] CR2: 0000000000000020 [ 1939.559375] ---[ end trace 82d44500f28f8708 ]--- Fixes: f34c4a35d879 ("l2tp: take PMTU from tunnel UDP socket") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit eed4d839b0cdf9d84b0a9bc63de90fd5e1e886fb ]

Use dst_entry held by sk_dst_get() to retrieve tunnel's PMTU.

The dst_mtu(__sk_dst_get(tunnel->sock)) call was racy. __sk_dst_get()
could return NULL if tunnel->sock->sk_dst_cache was reset just before the
call, thus making dst_mtu() dereference a NULL pointer:

[ 1937.661598] BUG: unable to handle kernel NULL pointer dereference at 0000000000000020
[ 1937.664005] IP: [<ffffffffa049db88>] pppol2tp_connect+0x33d/0x41e [l2tp_ppp]
[ 1937.664005] PGD daf0c067 PUD d9f93067 PMD 0
[ 1937.664005] Oops: 0000 [#1] SMP
[ 1937.664005] Modules linked in: l2tp_ppp l2tp_netlink l2tp_core ip6table_filter ip6_tables iptable_filter ip_tables ebtable_nat ebtables x_tables udp_tunnel pppoe pppox ppp_generic slhc deflate ctr twofish_generic twofish_x86_64_3way xts lrw gf128mul glue_helper twofish_x86_64 twofish_common blowfish_generic blowfish_x86_64 blowfish_common des_generic cbc xcbc rmd160 sha512_generic hmac crypto_null af_key xfrm_algo 8021q garp bridge stp llc tun atmtcp clip atm ext3 mbcache jbd iTCO_wdt coretemp kvm_intel iTCO_vendor_support kvm pcspkr evdev ehci_pci lpc_ich mfd_core i5400_edac edac_core i5k_amb shpchp button processor thermal_sys xfs crc32c_generic libcrc32c dm_mod usbhid sg hid sr_mod sd_mod cdrom crc_t10dif crct10dif_common ata_generic ahci ata_piix tg3 libahci libata uhci_hcd ptp ehci_hcd pps_core usbcore scsi_mod libphy usb_common [last unloaded: l2tp_core]
[ 1937.664005] CPU: 0 PID: 10022 Comm: l2tpstress Tainted: G           O   3.17.0-rc1 #1
[ 1937.664005] Hardware name: HP ProLiant DL160 G5, BIOS O12 08/22/2008
[ 1937.664005] task: ffff8800d8fda790 ti: ffff8800c43c4000 task.ti: ffff8800c43c4000
[ 1937.664005] RIP: 0010:[<ffffffffa049db88>]  [<ffffffffa049db88>] pppol2tp_connect+0x33d/0x41e [l2tp_ppp]
[ 1937.664005] RSP: 0018:ffff8800c43c7de8  EFLAGS: 00010282
[ 1937.664005] RAX: ffff8800da8a7240 RBX: ffff8800d8c64600 RCX: 000001c325a137b5
[ 1937.664005] RDX: 8c6318c6318c6320 RSI: 000000000000010c RDI: 0000000000000000
[ 1937.664005] RBP: ffff8800c43c7ea8 R08: 0000000000000000 R09: 0000000000000000
[ 1937.664005] R10: ffffffffa048e2c0 R11: ffff8800d8c64600 R12: ffff8800ca7a5000
[ 1937.664005] R13: ffff8800c439bf40 R14: 000000000000000c R15: 0000000000000009
[ 1937.664005] FS:  00007fd7f610f700(0000) GS:ffff88011a600000(0000) knlGS:0000000000000000
[ 1937.664005] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 1937.664005] CR2: 0000000000000020 CR3: 00000000d9d75000 CR4: 00000000000027e0
[ 1937.664005] Stack:
[ 1937.664005]  ffffffffa049da80 ffff8800d8fda790 000000000000005b ffff880000000009
[ 1937.664005]  ffff8800daf3f200 0000000000000003 ffff8800c43c7e48 ffffffff81109b57
[ 1937.664005]  ffffffff81109b0e ffffffff8114c566 0000000000000000 0000000000000000
[ 1937.664005] Call Trace:
[ 1937.664005]  [<ffffffffa049da80>] ? pppol2tp_connect+0x235/0x41e [l2tp_ppp]
[ 1937.664005]  [<ffffffff81109b57>] ? might_fault+0x9e/0xa5
[ 1937.664005]  [<ffffffff81109b0e>] ? might_fault+0x55/0xa5
[ 1937.664005]  [<ffffffff8114c566>] ? rcu_read_unlock+0x1c/0x26
[ 1937.664005]  [<ffffffff81309196>] SYSC_connect+0x87/0xb1
[ 1937.664005]  [<ffffffff813e56f7>] ? sysret_check+0x1b/0x56
[ 1937.664005]  [<ffffffff8107590d>] ? trace_hardirqs_on_caller+0x145/0x1a1
[ 1937.664005]  [<ffffffff81213dee>] ? trace_hardirqs_on_thunk+0x3a/0x3f
[ 1937.664005]  [<ffffffff8114c262>] ? spin_lock+0x9/0xb
[ 1937.664005]  [<ffffffff813092b4>] SyS_connect+0x9/0xb
[ 1937.664005]  [<ffffffff813e56d2>] system_call_fastpath+0x16/0x1b
[ 1937.664005] Code: 10 2a 84 81 e8 65 76 bd e0 65 ff 0c 25 10 bb 00 00 4d 85 ed 74 37 48 8b 85 60 ff ff ff 48 8b 80 88 01 00 00 48 8b b8 10 02 00 00 <48> 8b 47 20 ff 50 20 85 c0 74 0f 83 e8 28 89 83 10 01 00 00 89
[ 1937.664005] RIP  [<ffffffffa049db88>] pppol2tp_connect+0x33d/0x41e [l2tp_ppp]
[ 1937.664005]  RSP <ffff8800c43c7de8>
[ 1937.664005] CR2: 0000000000000020
[ 1939.559375] ---[ end trace 82d44500f28f8708 ]---

Fixes: f34c4a35d879 ("l2tp: take PMTU from tunnel UDP socket")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net/l2tp: don't fall back on UDP [get|set]sockopt 2014-08-07T21:30:27+00:00 Sasha Levin sasha.levin@oracle.com 2014-07-15T00:02:31+00:00 6718de2340c5865323f38644627b6b382e25fe26 commit 3cf521f7dc87c031617fd47e4b7aa2593c2f3daf upstream. The l2tp [get|set]sockopt() code has fallen back to the UDP functions for socket option levels != SOL_PPPOL2TP since day one, but that has never actually worked, since the l2tp socket isn't an inet socket. As David Miller points out: "If we wanted this to work, it'd have to look up the tunnel and then use tunnel->sk, but I wonder how useful that would be" Since this can never have worked so nobody could possibly have depended on that functionality, just remove the broken code and return -EINVAL. Reported-by: Sasha Levin <sasha.levin@oracle.com> Acked-by: James Chapman <jchapman@katalix.com> Acked-by: David Miller <davem@davemloft.net> Cc: Phil Turnbull <phil.turnbull@oracle.com> Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: Willy Tarreau <w@1wt.eu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 3cf521f7dc87c031617fd47e4b7aa2593c2f3daf upstream.

The l2tp [get|set]sockopt() code has fallen back to the UDP functions
for socket option levels != SOL_PPPOL2TP since day one, but that has
never actually worked, since the l2tp socket isn't an inet socket.

As David Miller points out:

  "If we wanted this to work, it'd have to look up the tunnel and then
   use tunnel->sk, but I wonder how useful that would be"

Since this can never have worked so nobody could possibly have depended
on that functionality, just remove the broken code and return -EINVAL.

Reported-by: Sasha Levin <sasha.levin@oracle.com>
Acked-by: James Chapman <jchapman@katalix.com>
Acked-by: David Miller <davem@davemloft.net>
Cc: Phil Turnbull <phil.turnbull@oracle.com>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
l2tp: take PMTU from tunnel UDP socket 2014-05-31T04:52:14+00:00 Dmitry Petukhov dmgenp@gmail.com 2014-04-08T20:23:20+00:00 6ea4dd539a9a5994c215ce48377483f7dba01613 [ Upstream commit f34c4a35d87949fbb0e0f31eba3c054e9f8199ba ] When l2tp driver tries to get PMTU for the tunnel destination, it uses the pointer to struct sock that represents PPPoX socket, while it should use the pointer that represents UDP socket of the tunnel. Signed-off-by: Dmitry Petukhov <dmgenp@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit f34c4a35d87949fbb0e0f31eba3c054e9f8199ba ]

When l2tp driver tries to get PMTU for the tunnel destination, it uses
the pointer to struct sock that represents PPPoX socket, while it
should use the pointer that represents UDP socket of the tunnel.

Signed-off-by: Dmitry Petukhov <dmgenp@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
inet: fix addr_len/msg->msg_namelen assignment in recv_error and rxpmtu functions 2013-12-08T15:29:25+00:00 Hannes Frederic Sowa hannes@stressinduktion.org 2013-11-22T23:46:12+00:00 08c62a109ed5f716556b2211f8cfd0d5fe6d18d2 [ Upstream commit 85fbaa75037d0b6b786ff18658ddf0b4014ce2a4 ] Commit bceaa90240b6019ed73b49965eac7d167610be69 ("inet: prevent leakage of uninitialized memory to user in recv syscalls") conditionally updated addr_len if the msg_name is written to. The recv_error and rxpmtu functions relied on the recvmsg functions to set up addr_len before. As this does not happen any more we have to pass addr_len to those functions as well and set it to the size of the corresponding sockaddr length. This broke traceroute and such. Fixes: bceaa90240b6 ("inet: prevent leakage of uninitialized memory to user in recv syscalls") Reported-by: Brad Spengler <spender@grsecurity.net> Reported-by: Tom Labanowski Cc: mpb <mpb.mail@gmail.com> Cc: David S. Miller <davem@davemloft.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 85fbaa75037d0b6b786ff18658ddf0b4014ce2a4 ]

Commit bceaa90240b6019ed73b49965eac7d167610be69 ("inet: prevent leakage
of uninitialized memory to user in recv syscalls") conditionally updated
addr_len if the msg_name is written to. The recv_error and rxpmtu
functions relied on the recvmsg functions to set up addr_len before.

As this does not happen any more we have to pass addr_len to those
functions as well and set it to the size of the corresponding sockaddr
length.

This broke traceroute and such.

Fixes: bceaa90240b6 ("inet: prevent leakage of uninitialized memory to user in recv syscalls")
Reported-by: Brad Spengler <spender@grsecurity.net>
Reported-by: Tom Labanowski
Cc: mpb <mpb.mail@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: rework recvmsg handler msg_name and msg_namelen logic 2013-12-08T15:29:25+00:00 Hannes Frederic Sowa hannes@stressinduktion.org 2013-11-21T02:14:22+00:00 2f73d7fde99d702cba6a05062c27605a6eef1b78 [ Upstream commit f3d3342602f8bcbf37d7c46641cb9bca7618eb1c ] This patch now always passes msg->msg_namelen as 0. recvmsg handlers must set msg_namelen to the proper size <= sizeof(struct sockaddr_storage) to return msg_name to the user. This prevents numerous uninitialized memory leaks we had in the recvmsg handlers and makes it harder for new code to accidentally leak uninitialized memory. Optimize for the case recvfrom is called with NULL as address. We don't need to copy the address at all, so set it to NULL before invoking the recvmsg handler. We can do so, because all the recvmsg handlers must cope with the case a plain read() is called on them. read() also sets msg_name to NULL. Also document these changes in include/linux/net.h as suggested by David Miller. Changes since RFC: Set msg->msg_name = NULL if user specified a NULL in msg_name but had a non-null msg_namelen in verify_iovec/verify_compat_iovec. This doesn't affect sendto as it would bail out earlier while trying to copy-in the address. It also more naturally reflects the logic by the callers of verify_iovec. With this change in place I could remove " if (!uaddr || msg_sys->msg_namelen == 0) msg->msg_name = NULL ". This change does not alter the user visible error logic as we ignore msg_namelen as long as msg_name is NULL. Also remove two unnecessary curly brackets in ___sys_recvmsg and change comments to netdev style. Cc: David Miller <davem@davemloft.net> Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit f3d3342602f8bcbf37d7c46641cb9bca7618eb1c ]

This patch now always passes msg->msg_namelen as 0. recvmsg handlers must
set msg_namelen to the proper size <= sizeof(struct sockaddr_storage)
to return msg_name to the user.

This prevents numerous uninitialized memory leaks we had in the
recvmsg handlers and makes it harder for new code to accidentally leak
uninitialized memory.

Optimize for the case recvfrom is called with NULL as address. We don't
need to copy the address at all, so set it to NULL before invoking the
recvmsg handler. We can do so, because all the recvmsg handlers must
cope with the case a plain read() is called on them. read() also sets
msg_name to NULL.

Also document these changes in include/linux/net.h as suggested by David
Miller.

Changes since RFC:

Set msg->msg_name = NULL if user specified a NULL in msg_name but had a
non-null msg_namelen in verify_iovec/verify_compat_iovec. This doesn't
affect sendto as it would bail out earlier while trying to copy-in the
address. It also more naturally reflects the logic by the callers of
verify_iovec.

With this change in place I could remove "
if (!uaddr || msg_sys->msg_namelen == 0)
	msg->msg_name = NULL
".

This change does not alter the user visible error logic as we ignore
msg_namelen as long as msg_name is NULL.

Also remove two unnecessary curly brackets in ___sys_recvmsg and change
comments to netdev style.

Cc: David Miller <davem@davemloft.net>
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
inet: prevent leakage of uninitialized memory to user in recv syscalls 2013-12-08T15:29:25+00:00 Hannes Frederic Sowa hannes@stressinduktion.org 2013-11-18T03:20:45+00:00 a2214488937a84d8d0b5a3b546f97b2485029a17 [ Upstream commit bceaa90240b6019ed73b49965eac7d167610be69 ] Only update *addr_len when we actually fill in sockaddr, otherwise we can return uninitialized memory from the stack to the caller in the recvfrom, recvmmsg and recvmsg syscalls. Drop the the (addr_len == NULL) checks because we only get called with a valid addr_len pointer either from sock_common_recvmsg or inet_recvmsg. If a blocking read waits on a socket which is concurrently shut down we now return zero and set msg_msgnamelen to 0. Reported-by: mpb <mpb.mail@gmail.com> Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit bceaa90240b6019ed73b49965eac7d167610be69 ]

Only update *addr_len when we actually fill in sockaddr, otherwise we
can return uninitialized memory from the stack to the caller in the
recvfrom, recvmmsg and recvmsg syscalls. Drop the the (addr_len == NULL)
checks because we only get called with a valid addr_len pointer either
from sock_common_recvmsg or inet_recvmsg.

If a blocking read waits on a socket which is concurrently shut down we
now return zero and set msg_msgnamelen to 0.

Reported-by: mpb <mpb.mail@gmail.com>
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
l2tp: must disable bh before calling l2tp_xmit_skb() 2013-11-04T12:31:02+00:00 Eric Dumazet edumazet@google.com 2013-10-10T13:30:09+00:00 a41536775e712e7b438400f73e927ffe4b21149c [ Upstream commit 455cc32bf128e114455d11ad919321ab89a2c312 ] François Cachereul made a very nice bug report and suspected the bh_lock_sock() / bh_unlok_sock() pair used in l2tp_xmit_skb() from process context was not good. This problem was added by commit 6af88da14ee284aaad6e4326da09a89191ab6165 ("l2tp: Fix locking in l2tp_core.c"). l2tp_eth_dev_xmit() runs from BH context, so we must disable BH from other l2tp_xmit_skb() users. [ 452.060011] BUG: soft lockup - CPU#1 stuck for 23s! [accel-pppd:6662] [ 452.061757] Modules linked in: l2tp_ppp l2tp_netlink l2tp_core pppoe pppox ppp_generic slhc ipv6 ext3 mbcache jbd virtio_balloon xfs exportfs dm_mod virtio_blk ata_generic virtio_net floppy ata_piix libata virtio_pci virtio_ring virtio [last unloaded: scsi_wait_scan] [ 452.064012] CPU 1 [ 452.080015] BUG: soft lockup - CPU#2 stuck for 23s! [accel-pppd:6643] [ 452.080015] CPU 2 [ 452.080015] [ 452.080015] Pid: 6643, comm: accel-pppd Not tainted 3.2.46.mini #1 Bochs Bochs [ 452.080015] RIP: 0010:[<ffffffff81059f6c>] [<ffffffff81059f6c>] do_raw_spin_lock+0x17/0x1f [ 452.080015] RSP: 0018:ffff88007125fc18 EFLAGS: 00000293 [ 452.080015] RAX: 000000000000aba9 RBX: ffffffff811d0703 RCX: 0000000000000000 [ 452.080015] RDX: 00000000000000ab RSI: ffff8800711f6896 RDI: ffff8800745c8110 [ 452.080015] RBP: ffff88007125fc18 R08: 0000000000000020 R09: 0000000000000000 [ 452.080015] R10: 0000000000000000 R11: 0000000000000280 R12: 0000000000000286 [ 452.080015] R13: 0000000000000020 R14: 0000000000000240 R15: 0000000000000000 [ 452.080015] FS: 00007fdc0cc24700(0000) GS:ffff8800b6f00000(0000) knlGS:0000000000000000 [ 452.080015] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 452.080015] CR2: 00007fdb054899b8 CR3: 0000000074404000 CR4: 00000000000006a0 [ 452.080015] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 452.080015] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 452.080015] Process accel-pppd (pid: 6643, threadinfo ffff88007125e000, task ffff8800b27e6dd0) [ 452.080015] Stack: [ 452.080015] ffff88007125fc28 ffffffff81256559 ffff88007125fc98 ffffffffa01b2bd1 [ 452.080015] ffff88007125fc58 000000000000000c 00000000029490d0 0000009c71dbe25e [ 452.080015] 000000000000005c 000000080000000e 0000000000000000 ffff880071170600 [ 452.080015] Call Trace: [ 452.080015] [<ffffffff81256559>] _raw_spin_lock+0xe/0x10 [ 452.080015] [<ffffffffa01b2bd1>] l2tp_xmit_skb+0x189/0x4ac [l2tp_core] [ 452.080015] [<ffffffffa01c2d36>] pppol2tp_sendmsg+0x15e/0x19c [l2tp_ppp] [ 452.080015] [<ffffffff811c7872>] __sock_sendmsg_nosec+0x22/0x24 [ 452.080015] [<ffffffff811c83bd>] sock_sendmsg+0xa1/0xb6 [ 452.080015] [<ffffffff81254e88>] ? __schedule+0x5c1/0x616 [ 452.080015] [<ffffffff8103c7c6>] ? __dequeue_signal+0xb7/0x10c [ 452.080015] [<ffffffff810bbd21>] ? fget_light+0x75/0x89 [ 452.080015] [<ffffffff811c8444>] ? sockfd_lookup_light+0x20/0x56 [ 452.080015] [<ffffffff811c9b34>] sys_sendto+0x10c/0x13b [ 452.080015] [<ffffffff8125cac2>] system_call_fastpath+0x16/0x1b [ 452.080015] Code: 81 48 89 e5 72 0c 31 c0 48 81 ff 45 66 25 81 0f 92 c0 5d c3 55 b8 00 01 00 00 48 89 e5 f0 66 0f c1 07 0f b6 d4 38 d0 74 06 f3 90 <8a> 07 eb f6 5d c3 90 90 55 48 89 e5 9c 58 0f 1f 44 00 00 5d c3 [ 452.080015] Call Trace: [ 452.080015] [<ffffffff81256559>] _raw_spin_lock+0xe/0x10 [ 452.080015] [<ffffffffa01b2bd1>] l2tp_xmit_skb+0x189/0x4ac [l2tp_core] [ 452.080015] [<ffffffffa01c2d36>] pppol2tp_sendmsg+0x15e/0x19c [l2tp_ppp] [ 452.080015] [<ffffffff811c7872>] __sock_sendmsg_nosec+0x22/0x24 [ 452.080015] [<ffffffff811c83bd>] sock_sendmsg+0xa1/0xb6 [ 452.080015] [<ffffffff81254e88>] ? __schedule+0x5c1/0x616 [ 452.080015] [<ffffffff8103c7c6>] ? __dequeue_signal+0xb7/0x10c [ 452.080015] [<ffffffff810bbd21>] ? fget_light+0x75/0x89 [ 452.080015] [<ffffffff811c8444>] ? sockfd_lookup_light+0x20/0x56 [ 452.080015] [<ffffffff811c9b34>] sys_sendto+0x10c/0x13b [ 452.080015] [<ffffffff8125cac2>] system_call_fastpath+0x16/0x1b [ 452.064012] [ 452.064012] Pid: 6662, comm: accel-pppd Not tainted 3.2.46.mini #1 Bochs Bochs [ 452.064012] RIP: 0010:[<ffffffff81059f6e>] [<ffffffff81059f6e>] do_raw_spin_lock+0x19/0x1f [ 452.064012] RSP: 0018:ffff8800b6e83ba0 EFLAGS: 00000297 [ 452.064012] RAX: 000000000000aaa9 RBX: ffff8800b6e83b40 RCX: 0000000000000002 [ 452.064012] RDX: 00000000000000aa RSI: 000000000000000a RDI: ffff8800745c8110 [ 452.064012] RBP: ffff8800b6e83ba0 R08: 000000000000c802 R09: 000000000000001c [ 452.064012] R10: ffff880071096c4e R11: 0000000000000006 R12: ffff8800b6e83b18 [ 452.064012] R13: ffffffff8125d51e R14: ffff8800b6e83ba0 R15: ffff880072a589c0 [ 452.064012] FS: 00007fdc0b81e700(0000) GS:ffff8800b6e80000(0000) knlGS:0000000000000000 [ 452.064012] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 452.064012] CR2: 0000000000625208 CR3: 0000000074404000 CR4: 00000000000006a0 [ 452.064012] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 452.064012] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 452.064012] Process accel-pppd (pid: 6662, threadinfo ffff88007129a000, task ffff8800744f7410) [ 452.064012] Stack: [ 452.064012] ffff8800b6e83bb0 ffffffff81256559 ffff8800b6e83bc0 ffffffff8121c64a [ 452.064012] ffff8800b6e83bf0 ffffffff8121ec7a ffff880072a589c0 ffff880071096c62 [ 452.064012] 0000000000000011 ffffffff81430024 ffff8800b6e83c80 ffffffff8121f276 [ 452.064012] Call Trace: [ 452.064012] <IRQ> [ 452.064012] [<ffffffff81256559>] _raw_spin_lock+0xe/0x10 [ 452.064012] [<ffffffff8121c64a>] spin_lock+0x9/0xb [ 452.064012] [<ffffffff8121ec7a>] udp_queue_rcv_skb+0x186/0x269 [ 452.064012] [<ffffffff8121f276>] __udp4_lib_rcv+0x297/0x4ae [ 452.064012] [<ffffffff8121c178>] ? raw_rcv+0xe9/0xf0 [ 452.064012] [<ffffffff8121f4a7>] udp_rcv+0x1a/0x1c [ 452.064012] [<ffffffff811fe385>] ip_local_deliver_finish+0x12b/0x1a5 [ 452.064012] [<ffffffff811fe54e>] ip_local_deliver+0x53/0x84 [ 452.064012] [<ffffffff811fe1d0>] ip_rcv_finish+0x2bc/0x2f3 [ 452.064012] [<ffffffff811fe78f>] ip_rcv+0x210/0x269 [ 452.064012] [<ffffffff8101911e>] ? kvm_clock_get_cycles+0x9/0xb [ 452.064012] [<ffffffff811d88cd>] __netif_receive_skb+0x3a5/0x3f7 [ 452.064012] [<ffffffff811d8eba>] netif_receive_skb+0x57/0x5e [ 452.064012] [<ffffffff811cf30f>] ? __netdev_alloc_skb+0x1f/0x3b [ 452.064012] [<ffffffffa0049126>] virtnet_poll+0x4ba/0x5a4 [virtio_net] [ 452.064012] [<ffffffff811d9417>] net_rx_action+0x73/0x184 [ 452.064012] [<ffffffffa01b2cc2>] ? l2tp_xmit_skb+0x27a/0x4ac [l2tp_core] [ 452.064012] [<ffffffff810343b9>] __do_softirq+0xc3/0x1a8 [ 452.064012] [<ffffffff81013b56>] ? ack_APIC_irq+0x10/0x12 [ 452.064012] [<ffffffff81256559>] ? _raw_spin_lock+0xe/0x10 [ 452.064012] [<ffffffff8125e0ac>] call_softirq+0x1c/0x26 [ 452.064012] [<ffffffff81003587>] do_softirq+0x45/0x82 [ 452.064012] [<ffffffff81034667>] irq_exit+0x42/0x9c [ 452.064012] [<ffffffff8125e146>] do_IRQ+0x8e/0xa5 [ 452.064012] [<ffffffff8125676e>] common_interrupt+0x6e/0x6e [ 452.064012] <EOI> [ 452.064012] [<ffffffff810b82a1>] ? kfree+0x8a/0xa3 [ 452.064012] [<ffffffffa01b2cc2>] ? l2tp_xmit_skb+0x27a/0x4ac [l2tp_core] [ 452.064012] [<ffffffffa01b2c25>] ? l2tp_xmit_skb+0x1dd/0x4ac [l2tp_core] [ 452.064012] [<ffffffffa01c2d36>] pppol2tp_sendmsg+0x15e/0x19c [l2tp_ppp] [ 452.064012] [<ffffffff811c7872>] __sock_sendmsg_nosec+0x22/0x24 [ 452.064012] [<ffffffff811c83bd>] sock_sendmsg+0xa1/0xb6 [ 452.064012] [<ffffffff81254e88>] ? __schedule+0x5c1/0x616 [ 452.064012] [<ffffffff8103c7c6>] ? __dequeue_signal+0xb7/0x10c [ 452.064012] [<ffffffff810bbd21>] ? fget_light+0x75/0x89 [ 452.064012] [<ffffffff811c8444>] ? sockfd_lookup_light+0x20/0x56 [ 452.064012] [<ffffffff811c9b34>] sys_sendto+0x10c/0x13b [ 452.064012] [<ffffffff8125cac2>] system_call_fastpath+0x16/0x1b [ 452.064012] Code: 89 e5 72 0c 31 c0 48 81 ff 45 66 25 81 0f 92 c0 5d c3 55 b8 00 01 00 00 48 89 e5 f0 66 0f c1 07 0f b6 d4 38 d0 74 06 f3 90 8a 07 <eb> f6 5d c3 90 90 55 48 89 e5 9c 58 0f 1f 44 00 00 5d c3 55 48 [ 452.064012] Call Trace: [ 452.064012] <IRQ> [<ffffffff81256559>] _raw_spin_lock+0xe/0x10 [ 452.064012] [<ffffffff8121c64a>] spin_lock+0x9/0xb [ 452.064012] [<ffffffff8121ec7a>] udp_queue_rcv_skb+0x186/0x269 [ 452.064012] [<ffffffff8121f276>] __udp4_lib_rcv+0x297/0x4ae [ 452.064012] [<ffffffff8121c178>] ? raw_rcv+0xe9/0xf0 [ 452.064012] [<ffffffff8121f4a7>] udp_rcv+0x1a/0x1c [ 452.064012] [<ffffffff811fe385>] ip_local_deliver_finish+0x12b/0x1a5 [ 452.064012] [<ffffffff811fe54e>] ip_local_deliver+0x53/0x84 [ 452.064012] [<ffffffff811fe1d0>] ip_rcv_finish+0x2bc/0x2f3 [ 452.064012] [<ffffffff811fe78f>] ip_rcv+0x210/0x269 [ 452.064012] [<ffffffff8101911e>] ? kvm_clock_get_cycles+0x9/0xb [ 452.064012] [<ffffffff811d88cd>] __netif_receive_skb+0x3a5/0x3f7 [ 452.064012] [<ffffffff811d8eba>] netif_receive_skb+0x57/0x5e [ 452.064012] [<ffffffff811cf30f>] ? __netdev_alloc_skb+0x1f/0x3b [ 452.064012] [<ffffffffa0049126>] virtnet_poll+0x4ba/0x5a4 [virtio_net] [ 452.064012] [<ffffffff811d9417>] net_rx_action+0x73/0x184 [ 452.064012] [<ffffffffa01b2cc2>] ? l2tp_xmit_skb+0x27a/0x4ac [l2tp_core] [ 452.064012] [<ffffffff810343b9>] __do_softirq+0xc3/0x1a8 [ 452.064012] [<ffffffff81013b56>] ? ack_APIC_irq+0x10/0x12 [ 452.064012] [<ffffffff81256559>] ? _raw_spin_lock+0xe/0x10 [ 452.064012] [<ffffffff8125e0ac>] call_softirq+0x1c/0x26 [ 452.064012] [<ffffffff81003587>] do_softirq+0x45/0x82 [ 452.064012] [<ffffffff81034667>] irq_exit+0x42/0x9c [ 452.064012] [<ffffffff8125e146>] do_IRQ+0x8e/0xa5 [ 452.064012] [<ffffffff8125676e>] common_interrupt+0x6e/0x6e [ 452.064012] <EOI> [<ffffffff810b82a1>] ? kfree+0x8a/0xa3 [ 452.064012] [<ffffffffa01b2cc2>] ? l2tp_xmit_skb+0x27a/0x4ac [l2tp_core] [ 452.064012] [<ffffffffa01b2c25>] ? l2tp_xmit_skb+0x1dd/0x4ac [l2tp_core] [ 452.064012] [<ffffffffa01c2d36>] pppol2tp_sendmsg+0x15e/0x19c [l2tp_ppp] [ 452.064012] [<ffffffff811c7872>] __sock_sendmsg_nosec+0x22/0x24 [ 452.064012] [<ffffffff811c83bd>] sock_sendmsg+0xa1/0xb6 [ 452.064012] [<ffffffff81254e88>] ? __schedule+0x5c1/0x616 [ 452.064012] [<ffffffff8103c7c6>] ? __dequeue_signal+0xb7/0x10c [ 452.064012] [<ffffffff810bbd21>] ? fget_light+0x75/0x89 [ 452.064012] [<ffffffff811c8444>] ? sockfd_lookup_light+0x20/0x56 [ 452.064012] [<ffffffff811c9b34>] sys_sendto+0x10c/0x13b [ 452.064012] [<ffffffff8125cac2>] system_call_fastpath+0x16/0x1b Reported-by: François Cachereul <f.cachereul@alphalink.fr> Tested-by: François Cachereul <f.cachereul@alphalink.fr> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 455cc32bf128e114455d11ad919321ab89a2c312 ]

François Cachereul made a very nice bug report and suspected
the bh_lock_sock() / bh_unlok_sock() pair used in l2tp_xmit_skb() from
process context was not good.

This problem was added by commit 6af88da14ee284aaad6e4326da09a89191ab6165
("l2tp: Fix locking in l2tp_core.c").

l2tp_eth_dev_xmit() runs from BH context, so we must disable BH
from other l2tp_xmit_skb() users.

[  452.060011] BUG: soft lockup - CPU#1 stuck for 23s! [accel-pppd:6662]
[  452.061757] Modules linked in: l2tp_ppp l2tp_netlink l2tp_core pppoe pppox
ppp_generic slhc ipv6 ext3 mbcache jbd virtio_balloon xfs exportfs dm_mod
virtio_blk ata_generic virtio_net floppy ata_piix libata virtio_pci virtio_ring virtio [last unloaded: scsi_wait_scan]
[  452.064012] CPU 1
[  452.080015] BUG: soft lockup - CPU#2 stuck for 23s! [accel-pppd:6643]
[  452.080015] CPU 2
[  452.080015]
[  452.080015] Pid: 6643, comm: accel-pppd Not tainted 3.2.46.mini #1 Bochs Bochs
[  452.080015] RIP: 0010:[<ffffffff81059f6c>]  [<ffffffff81059f6c>] do_raw_spin_lock+0x17/0x1f
[  452.080015] RSP: 0018:ffff88007125fc18  EFLAGS: 00000293
[  452.080015] RAX: 000000000000aba9 RBX: ffffffff811d0703 RCX: 0000000000000000
[  452.080015] RDX: 00000000000000ab RSI: ffff8800711f6896 RDI: ffff8800745c8110
[  452.080015] RBP: ffff88007125fc18 R08: 0000000000000020 R09: 0000000000000000
[  452.080015] R10: 0000000000000000 R11: 0000000000000280 R12: 0000000000000286
[  452.080015] R13: 0000000000000020 R14: 0000000000000240 R15: 0000000000000000
[  452.080015] FS:  00007fdc0cc24700(0000) GS:ffff8800b6f00000(0000) knlGS:0000000000000000
[  452.080015] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  452.080015] CR2: 00007fdb054899b8 CR3: 0000000074404000 CR4: 00000000000006a0
[  452.080015] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  452.080015] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[  452.080015] Process accel-pppd (pid: 6643, threadinfo ffff88007125e000, task ffff8800b27e6dd0)
[  452.080015] Stack:
[  452.080015]  ffff88007125fc28 ffffffff81256559 ffff88007125fc98 ffffffffa01b2bd1
[  452.080015]  ffff88007125fc58 000000000000000c 00000000029490d0 0000009c71dbe25e
[  452.080015]  000000000000005c 000000080000000e 0000000000000000 ffff880071170600
[  452.080015] Call Trace:
[  452.080015]  [<ffffffff81256559>] _raw_spin_lock+0xe/0x10
[  452.080015]  [<ffffffffa01b2bd1>] l2tp_xmit_skb+0x189/0x4ac [l2tp_core]
[  452.080015]  [<ffffffffa01c2d36>] pppol2tp_sendmsg+0x15e/0x19c [l2tp_ppp]
[  452.080015]  [<ffffffff811c7872>] __sock_sendmsg_nosec+0x22/0x24
[  452.080015]  [<ffffffff811c83bd>] sock_sendmsg+0xa1/0xb6
[  452.080015]  [<ffffffff81254e88>] ? __schedule+0x5c1/0x616
[  452.080015]  [<ffffffff8103c7c6>] ? __dequeue_signal+0xb7/0x10c
[  452.080015]  [<ffffffff810bbd21>] ? fget_light+0x75/0x89
[  452.080015]  [<ffffffff811c8444>] ? sockfd_lookup_light+0x20/0x56
[  452.080015]  [<ffffffff811c9b34>] sys_sendto+0x10c/0x13b
[  452.080015]  [<ffffffff8125cac2>] system_call_fastpath+0x16/0x1b
[  452.080015] Code: 81 48 89 e5 72 0c 31 c0 48 81 ff 45 66 25 81 0f 92 c0 5d c3 55 b8 00 01 00 00 48 89 e5 f0 66 0f c1 07 0f b6 d4 38 d0 74 06 f3 90 <8a> 07 eb f6 5d c3 90 90 55 48 89 e5 9c 58 0f 1f 44 00 00 5d c3
[  452.080015] Call Trace:
[  452.080015]  [<ffffffff81256559>] _raw_spin_lock+0xe/0x10
[  452.080015]  [<ffffffffa01b2bd1>] l2tp_xmit_skb+0x189/0x4ac [l2tp_core]
[  452.080015]  [<ffffffffa01c2d36>] pppol2tp_sendmsg+0x15e/0x19c [l2tp_ppp]
[  452.080015]  [<ffffffff811c7872>] __sock_sendmsg_nosec+0x22/0x24
[  452.080015]  [<ffffffff811c83bd>] sock_sendmsg+0xa1/0xb6
[  452.080015]  [<ffffffff81254e88>] ? __schedule+0x5c1/0x616
[  452.080015]  [<ffffffff8103c7c6>] ? __dequeue_signal+0xb7/0x10c
[  452.080015]  [<ffffffff810bbd21>] ? fget_light+0x75/0x89
[  452.080015]  [<ffffffff811c8444>] ? sockfd_lookup_light+0x20/0x56
[  452.080015]  [<ffffffff811c9b34>] sys_sendto+0x10c/0x13b
[  452.080015]  [<ffffffff8125cac2>] system_call_fastpath+0x16/0x1b
[  452.064012]
[  452.064012] Pid: 6662, comm: accel-pppd Not tainted 3.2.46.mini #1 Bochs Bochs
[  452.064012] RIP: 0010:[<ffffffff81059f6e>]  [<ffffffff81059f6e>] do_raw_spin_lock+0x19/0x1f
[  452.064012] RSP: 0018:ffff8800b6e83ba0  EFLAGS: 00000297
[  452.064012] RAX: 000000000000aaa9 RBX: ffff8800b6e83b40 RCX: 0000000000000002
[  452.064012] RDX: 00000000000000aa RSI: 000000000000000a RDI: ffff8800745c8110
[  452.064012] RBP: ffff8800b6e83ba0 R08: 000000000000c802 R09: 000000000000001c
[  452.064012] R10: ffff880071096c4e R11: 0000000000000006 R12: ffff8800b6e83b18
[  452.064012] R13: ffffffff8125d51e R14: ffff8800b6e83ba0 R15: ffff880072a589c0
[  452.064012] FS:  00007fdc0b81e700(0000) GS:ffff8800b6e80000(0000) knlGS:0000000000000000
[  452.064012] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  452.064012] CR2: 0000000000625208 CR3: 0000000074404000 CR4: 00000000000006a0
[  452.064012] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  452.064012] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[  452.064012] Process accel-pppd (pid: 6662, threadinfo ffff88007129a000, task ffff8800744f7410)
[  452.064012] Stack:
[  452.064012]  ffff8800b6e83bb0 ffffffff81256559 ffff8800b6e83bc0 ffffffff8121c64a
[  452.064012]  ffff8800b6e83bf0 ffffffff8121ec7a ffff880072a589c0 ffff880071096c62
[  452.064012]  0000000000000011 ffffffff81430024 ffff8800b6e83c80 ffffffff8121f276
[  452.064012] Call Trace:
[  452.064012]  <IRQ>
[  452.064012]  [<ffffffff81256559>] _raw_spin_lock+0xe/0x10
[  452.064012]  [<ffffffff8121c64a>] spin_lock+0x9/0xb
[  452.064012]  [<ffffffff8121ec7a>] udp_queue_rcv_skb+0x186/0x269
[  452.064012]  [<ffffffff8121f276>] __udp4_lib_rcv+0x297/0x4ae
[  452.064012]  [<ffffffff8121c178>] ? raw_rcv+0xe9/0xf0
[  452.064012]  [<ffffffff8121f4a7>] udp_rcv+0x1a/0x1c
[  452.064012]  [<ffffffff811fe385>] ip_local_deliver_finish+0x12b/0x1a5
[  452.064012]  [<ffffffff811fe54e>] ip_local_deliver+0x53/0x84
[  452.064012]  [<ffffffff811fe1d0>] ip_rcv_finish+0x2bc/0x2f3
[  452.064012]  [<ffffffff811fe78f>] ip_rcv+0x210/0x269
[  452.064012]  [<ffffffff8101911e>] ? kvm_clock_get_cycles+0x9/0xb
[  452.064012]  [<ffffffff811d88cd>] __netif_receive_skb+0x3a5/0x3f7
[  452.064012]  [<ffffffff811d8eba>] netif_receive_skb+0x57/0x5e
[  452.064012]  [<ffffffff811cf30f>] ? __netdev_alloc_skb+0x1f/0x3b
[  452.064012]  [<ffffffffa0049126>] virtnet_poll+0x4ba/0x5a4 [virtio_net]
[  452.064012]  [<ffffffff811d9417>] net_rx_action+0x73/0x184
[  452.064012]  [<ffffffffa01b2cc2>] ? l2tp_xmit_skb+0x27a/0x4ac [l2tp_core]
[  452.064012]  [<ffffffff810343b9>] __do_softirq+0xc3/0x1a8
[  452.064012]  [<ffffffff81013b56>] ? ack_APIC_irq+0x10/0x12
[  452.064012]  [<ffffffff81256559>] ? _raw_spin_lock+0xe/0x10
[  452.064012]  [<ffffffff8125e0ac>] call_softirq+0x1c/0x26
[  452.064012]  [<ffffffff81003587>] do_softirq+0x45/0x82
[  452.064012]  [<ffffffff81034667>] irq_exit+0x42/0x9c
[  452.064012]  [<ffffffff8125e146>] do_IRQ+0x8e/0xa5
[  452.064012]  [<ffffffff8125676e>] common_interrupt+0x6e/0x6e
[  452.064012]  <EOI>
[  452.064012]  [<ffffffff810b82a1>] ? kfree+0x8a/0xa3
[  452.064012]  [<ffffffffa01b2cc2>] ? l2tp_xmit_skb+0x27a/0x4ac [l2tp_core]
[  452.064012]  [<ffffffffa01b2c25>] ? l2tp_xmit_skb+0x1dd/0x4ac [l2tp_core]
[  452.064012]  [<ffffffffa01c2d36>] pppol2tp_sendmsg+0x15e/0x19c [l2tp_ppp]
[  452.064012]  [<ffffffff811c7872>] __sock_sendmsg_nosec+0x22/0x24
[  452.064012]  [<ffffffff811c83bd>] sock_sendmsg+0xa1/0xb6
[  452.064012]  [<ffffffff81254e88>] ? __schedule+0x5c1/0x616
[  452.064012]  [<ffffffff8103c7c6>] ? __dequeue_signal+0xb7/0x10c
[  452.064012]  [<ffffffff810bbd21>] ? fget_light+0x75/0x89
[  452.064012]  [<ffffffff811c8444>] ? sockfd_lookup_light+0x20/0x56
[  452.064012]  [<ffffffff811c9b34>] sys_sendto+0x10c/0x13b
[  452.064012]  [<ffffffff8125cac2>] system_call_fastpath+0x16/0x1b
[  452.064012] Code: 89 e5 72 0c 31 c0 48 81 ff 45 66 25 81 0f 92 c0 5d c3 55 b8 00 01 00 00 48 89 e5 f0 66 0f c1 07 0f b6 d4 38 d0 74 06 f3 90 8a 07 <eb> f6 5d c3 90 90 55 48 89 e5 9c 58 0f 1f 44 00 00 5d c3 55 48
[  452.064012] Call Trace:
[  452.064012]  <IRQ>  [<ffffffff81256559>] _raw_spin_lock+0xe/0x10
[  452.064012]  [<ffffffff8121c64a>] spin_lock+0x9/0xb
[  452.064012]  [<ffffffff8121ec7a>] udp_queue_rcv_skb+0x186/0x269
[  452.064012]  [<ffffffff8121f276>] __udp4_lib_rcv+0x297/0x4ae
[  452.064012]  [<ffffffff8121c178>] ? raw_rcv+0xe9/0xf0
[  452.064012]  [<ffffffff8121f4a7>] udp_rcv+0x1a/0x1c
[  452.064012]  [<ffffffff811fe385>] ip_local_deliver_finish+0x12b/0x1a5
[  452.064012]  [<ffffffff811fe54e>] ip_local_deliver+0x53/0x84
[  452.064012]  [<ffffffff811fe1d0>] ip_rcv_finish+0x2bc/0x2f3
[  452.064012]  [<ffffffff811fe78f>] ip_rcv+0x210/0x269
[  452.064012]  [<ffffffff8101911e>] ? kvm_clock_get_cycles+0x9/0xb
[  452.064012]  [<ffffffff811d88cd>] __netif_receive_skb+0x3a5/0x3f7
[  452.064012]  [<ffffffff811d8eba>] netif_receive_skb+0x57/0x5e
[  452.064012]  [<ffffffff811cf30f>] ? __netdev_alloc_skb+0x1f/0x3b
[  452.064012]  [<ffffffffa0049126>] virtnet_poll+0x4ba/0x5a4 [virtio_net]
[  452.064012]  [<ffffffff811d9417>] net_rx_action+0x73/0x184
[  452.064012]  [<ffffffffa01b2cc2>] ? l2tp_xmit_skb+0x27a/0x4ac [l2tp_core]
[  452.064012]  [<ffffffff810343b9>] __do_softirq+0xc3/0x1a8
[  452.064012]  [<ffffffff81013b56>] ? ack_APIC_irq+0x10/0x12
[  452.064012]  [<ffffffff81256559>] ? _raw_spin_lock+0xe/0x10
[  452.064012]  [<ffffffff8125e0ac>] call_softirq+0x1c/0x26
[  452.064012]  [<ffffffff81003587>] do_softirq+0x45/0x82
[  452.064012]  [<ffffffff81034667>] irq_exit+0x42/0x9c
[  452.064012]  [<ffffffff8125e146>] do_IRQ+0x8e/0xa5
[  452.064012]  [<ffffffff8125676e>] common_interrupt+0x6e/0x6e
[  452.064012]  <EOI>  [<ffffffff810b82a1>] ? kfree+0x8a/0xa3
[  452.064012]  [<ffffffffa01b2cc2>] ? l2tp_xmit_skb+0x27a/0x4ac [l2tp_core]
[  452.064012]  [<ffffffffa01b2c25>] ? l2tp_xmit_skb+0x1dd/0x4ac [l2tp_core]
[  452.064012]  [<ffffffffa01c2d36>] pppol2tp_sendmsg+0x15e/0x19c [l2tp_ppp]
[  452.064012]  [<ffffffff811c7872>] __sock_sendmsg_nosec+0x22/0x24
[  452.064012]  [<ffffffff811c83bd>] sock_sendmsg+0xa1/0xb6
[  452.064012]  [<ffffffff81254e88>] ? __schedule+0x5c1/0x616
[  452.064012]  [<ffffffff8103c7c6>] ? __dequeue_signal+0xb7/0x10c
[  452.064012]  [<ffffffff810bbd21>] ? fget_light+0x75/0x89
[  452.064012]  [<ffffffff811c8444>] ? sockfd_lookup_light+0x20/0x56
[  452.064012]  [<ffffffff811c9b34>] sys_sendto+0x10c/0x13b
[  452.064012]  [<ffffffff8125cac2>] system_call_fastpath+0x16/0x1b

Reported-by: François Cachereul <f.cachereul@alphalink.fr>
Tested-by: François Cachereul <f.cachereul@alphalink.fr>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
l2tp: Fix build warning with ipv6 disabled. 2013-11-04T12:31:00+00:00 David S. Miller davem@davemloft.net 2013-10-08T19:44:26+00:00 d980ed627b35d4685a4a27561dc3fc7a09226dab [ Upstream commit 8d8a51e26a6d415e1470759f2cf5f3ee3ee86196 ] net/l2tp/l2tp_core.c: In function ‘l2tp_verify_udp_checksum’: net/l2tp/l2tp_core.c:499:22: warning: unused variable ‘tunnel’ [-Wunused-variable] Create a helper "l2tp_tunnel()" to facilitate this, and as a side effect get rid of a bunch of unnecessary void pointer casts. Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 8d8a51e26a6d415e1470759f2cf5f3ee3ee86196 ]

net/l2tp/l2tp_core.c: In function ‘l2tp_verify_udp_checksum’:
net/l2tp/l2tp_core.c:499:22: warning: unused variable ‘tunnel’ [-Wunused-variable]

Create a helper "l2tp_tunnel()" to facilitate this, and as a side
effect get rid of a bunch of unnecessary void pointer casts.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
l2tp: fix kernel panic when using IPv4-mapped IPv6 addresses 2013-11-04T12:31:00+00:00 François CACHEREUL f.cachereul@alphalink.fr 2013-10-02T08:16:02+00:00 bd83cd77073e5c54a88f976d6d6c785a1a80b0c0 [ Upstream commit e18503f41f9b12132c95d7c31ca6ee5155e44e5c ] IPv4 mapped addresses cause kernel panic. The patch juste check whether the IPv6 address is an IPv4 mapped address. If so, use IPv4 API instead of IPv6. [ 940.026915] general protection fault: 0000 [#1] [ 940.026915] Modules linked in: l2tp_ppp l2tp_netlink l2tp_core pppox ppp_generic slhc loop psmouse [ 940.026915] CPU: 0 PID: 3184 Comm: memcheck-amd64- Not tainted 3.11.0+ #1 [ 940.026915] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007 [ 940.026915] task: ffff880007130e20 ti: ffff88000737e000 task.ti: ffff88000737e000 [ 940.026915] RIP: 0010:[<ffffffff81333780>] [<ffffffff81333780>] ip6_xmit+0x276/0x326 [ 940.026915] RSP: 0018:ffff88000737fd28 EFLAGS: 00010286 [ 940.026915] RAX: c748521a75ceff48 RBX: ffff880000c30800 RCX: 0000000000000000 [ 940.026915] RDX: ffff88000075cc4e RSI: 0000000000000028 RDI: ffff8800060e5a40 [ 940.026915] RBP: ffff8800060e5a40 R08: 0000000000000000 R09: ffff88000075cc90 [ 940.026915] R10: 0000000000000000 R11: 0000000000000000 R12: ffff88000737fda0 [ 940.026915] R13: 0000000000000000 R14: 0000000000002000 R15: ffff880005d3b580 [ 940.026915] FS: 00007f163dc5e800(0000) GS:ffffffff81623000(0000) knlGS:0000000000000000 [ 940.026915] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 940.026915] CR2: 00000004032dc940 CR3: 0000000005c25000 CR4: 00000000000006f0 [ 940.026915] Stack: [ 940.026915] ffff88000075cc4e ffffffff81694e90 ffff880000c30b38 0000000000000020 [ 940.026915] 11000000523c4bac ffff88000737fdb4 0000000000000000 ffff880000c30800 [ 940.026915] ffff880005d3b580 ffff880000c30b38 ffff8800060e5a40 0000000000000020 [ 940.026915] Call Trace: [ 940.026915] [<ffffffff81356cc3>] ? inet6_csk_xmit+0xa4/0xc4 [ 940.026915] [<ffffffffa0038535>] ? l2tp_xmit_skb+0x503/0x55a [l2tp_core] [ 940.026915] [<ffffffff812b8d3b>] ? pskb_expand_head+0x161/0x214 [ 940.026915] [<ffffffffa003e91d>] ? pppol2tp_xmit+0xf2/0x143 [l2tp_ppp] [ 940.026915] [<ffffffffa00292e0>] ? ppp_channel_push+0x36/0x8b [ppp_generic] [ 940.026915] [<ffffffffa00293fe>] ? ppp_write+0xaf/0xc5 [ppp_generic] [ 940.026915] [<ffffffff8110ead4>] ? vfs_write+0xa2/0x106 [ 940.026915] [<ffffffff8110edd6>] ? SyS_write+0x56/0x8a [ 940.026915] [<ffffffff81378ac0>] ? system_call_fastpath+0x16/0x1b [ 940.026915] Code: 00 49 8b 8f d8 00 00 00 66 83 7c 11 02 00 74 60 49 8b 47 58 48 83 e0 fe 48 8b 80 18 01 00 00 48 85 c0 74 13 48 8b 80 78 02 00 00 <48> ff 40 28 41 8b 57 68 48 01 50 30 48 8b 54 24 08 49 c7 c1 51 [ 940.026915] RIP [<ffffffff81333780>] ip6_xmit+0x276/0x326 [ 940.026915] RSP <ffff88000737fd28> [ 940.057945] ---[ end trace be8aba9a61c8b7f3 ]--- [ 940.058583] Kernel panic - not syncing: Fatal exception in interrupt Signed-off-by: François CACHEREUL <f.cachereul@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit e18503f41f9b12132c95d7c31ca6ee5155e44e5c ]

IPv4 mapped addresses cause kernel panic.
The patch juste check whether the IPv6 address is an IPv4 mapped
address. If so, use IPv4 API instead of IPv6.

[  940.026915] general protection fault: 0000 [#1]
[  940.026915] Modules linked in: l2tp_ppp l2tp_netlink l2tp_core pppox ppp_generic slhc loop psmouse
[  940.026915] CPU: 0 PID: 3184 Comm: memcheck-amd64- Not tainted 3.11.0+ #1
[  940.026915] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
[  940.026915] task: ffff880007130e20 ti: ffff88000737e000 task.ti: ffff88000737e000
[  940.026915] RIP: 0010:[<ffffffff81333780>]  [<ffffffff81333780>] ip6_xmit+0x276/0x326
[  940.026915] RSP: 0018:ffff88000737fd28  EFLAGS: 00010286
[  940.026915] RAX: c748521a75ceff48 RBX: ffff880000c30800 RCX: 0000000000000000
[  940.026915] RDX: ffff88000075cc4e RSI: 0000000000000028 RDI: ffff8800060e5a40
[  940.026915] RBP: ffff8800060e5a40 R08: 0000000000000000 R09: ffff88000075cc90
[  940.026915] R10: 0000000000000000 R11: 0000000000000000 R12: ffff88000737fda0
[  940.026915] R13: 0000000000000000 R14: 0000000000002000 R15: ffff880005d3b580
[  940.026915] FS:  00007f163dc5e800(0000) GS:ffffffff81623000(0000) knlGS:0000000000000000
[  940.026915] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  940.026915] CR2: 00000004032dc940 CR3: 0000000005c25000 CR4: 00000000000006f0
[  940.026915] Stack:
[  940.026915]  ffff88000075cc4e ffffffff81694e90 ffff880000c30b38 0000000000000020
[  940.026915]  11000000523c4bac ffff88000737fdb4 0000000000000000 ffff880000c30800
[  940.026915]  ffff880005d3b580 ffff880000c30b38 ffff8800060e5a40 0000000000000020
[  940.026915] Call Trace:
[  940.026915]  [<ffffffff81356cc3>] ? inet6_csk_xmit+0xa4/0xc4
[  940.026915]  [<ffffffffa0038535>] ? l2tp_xmit_skb+0x503/0x55a [l2tp_core]
[  940.026915]  [<ffffffff812b8d3b>] ? pskb_expand_head+0x161/0x214
[  940.026915]  [<ffffffffa003e91d>] ? pppol2tp_xmit+0xf2/0x143 [l2tp_ppp]
[  940.026915]  [<ffffffffa00292e0>] ? ppp_channel_push+0x36/0x8b [ppp_generic]
[  940.026915]  [<ffffffffa00293fe>] ? ppp_write+0xaf/0xc5 [ppp_generic]
[  940.026915]  [<ffffffff8110ead4>] ? vfs_write+0xa2/0x106
[  940.026915]  [<ffffffff8110edd6>] ? SyS_write+0x56/0x8a
[  940.026915]  [<ffffffff81378ac0>] ? system_call_fastpath+0x16/0x1b
[  940.026915] Code: 00 49 8b 8f d8 00 00 00 66 83 7c 11 02 00 74 60 49
8b 47 58 48 83 e0 fe 48 8b 80 18 01 00 00 48 85 c0 74 13 48 8b 80 78 02
00 00 <48> ff 40 28 41 8b 57 68 48 01 50 30 48 8b 54 24 08 49 c7 c1 51
[  940.026915] RIP  [<ffffffff81333780>] ip6_xmit+0x276/0x326
[  940.026915]  RSP <ffff88000737fd28>
[  940.057945] ---[ end trace be8aba9a61c8b7f3 ]---
[  940.058583] Kernel panic - not syncing: Fatal exception in interrupt

Signed-off-by: François CACHEREUL <f.cachereul@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
l2tp: add missing .owner to struct pppox_proto 2013-07-28T23:29:49+00:00 Wei Yongjun yongjun_wei@trendmicro.com.cn 2013-07-02T01:02:07+00:00 ed7f614ab8c605aadfa163d468a980642b3929da [ Upstream commit e1558a93b61962710733dc8c11a2bc765607f1cd ] Add missing .owner of struct pppox_proto. This prevents the module from being removed from underneath its users. Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit e1558a93b61962710733dc8c11a2bc765607f1cd ]

Add missing .owner of struct pppox_proto. This prevents the
module from being removed from underneath its users.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>