linux-stable.git/net, branch v3.16.50 Linux kernel stable tree netfilter; Add some missing default cases to switch statements in nft_reject. 2017-11-11T13:33:55+00:00 David S. Miller davem@davemloft.net 2015-04-27T17:20:34+00:00 a927a508ae2dcb088638de54455152c979b57d5f commit 129d23a56623eea0947a05288158d76dc7f2f0ac upstream. This fixes: ==================== net/netfilter/nft_reject.c: In function ‘nft_reject_dump’: net/netfilter/nft_reject.c:61:2: warning: enumeration value ‘NFT_REJECT_TCP_RST’ not handled in switch [-Wswitch] switch (priv->type) { ^ net/netfilter/nft_reject.c:61:2: warning: enumeration value ‘NFT_REJECT_ICMPX_UNREACH’ not handled in switch [-Wswi\ tch] net/netfilter/nft_reject_inet.c: In function ‘nft_reject_inet_dump’: net/netfilter/nft_reject_inet.c:105:2: warning: enumeration value ‘NFT_REJECT_TCP_RST’ not handled in switch [-Wswi\ tch] switch (priv->type) { ^ ==================== Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 129d23a56623eea0947a05288158d76dc7f2f0ac upstream.

This fixes:

====================
net/netfilter/nft_reject.c: In function ‘nft_reject_dump’:
net/netfilter/nft_reject.c:61:2: warning: enumeration value ‘NFT_REJECT_TCP_RST’ not handled in switch [-Wswitch]
  switch (priv->type) {
  ^
net/netfilter/nft_reject.c:61:2: warning: enumeration value ‘NFT_REJECT_ICMPX_UNREACH’ not handled in switch [-Wswi\
tch]
net/netfilter/nft_reject_inet.c: In function ‘nft_reject_inet_dump’:
net/netfilter/nft_reject_inet.c:105:2: warning: enumeration value ‘NFT_REJECT_TCP_RST’ not handled in switch [-Wswi\
tch]
  switch (priv->type) {
  ^
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
netfilter: Fix switch statement warnings with recent gcc. 2017-11-11T13:33:54+00:00 David Miller davem@davemloft.net 2015-04-08T03:05:42+00:00 3d4abcb83fd3ad085444c0a87ad4b75bc79a7f63 commit c1f866767777d1c6abae0ec57effffcb72017c00 upstream. More recent GCC warns about two kinds of switch statement uses: 1) Switching on an enumeration, but not having an explicit case statement for all members of the enumeration. To show the compiler this is intentional, we simply add a default case with nothing more than a break statement. 2) Switching on a boolean value. I think this warning is dumb but nevertheless you get it wholesale with -Wswitch. This patch cures all such warnings in netfilter. Signed-off-by: David S. Miller <davem@davemloft.net> Acked-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit c1f866767777d1c6abae0ec57effffcb72017c00 upstream.

More recent GCC warns about two kinds of switch statement uses:

1) Switching on an enumeration, but not having an explicit case
   statement for all members of the enumeration.  To show the
   compiler this is intentional, we simply add a default case
   with nothing more than a break statement.

2) Switching on a boolean value.  I think this warning is dumb
   but nevertheless you get it wholesale with -Wswitch.

This patch cures all such warnings in netfilter.

Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
net: caif: fix misleading indentation 2017-11-11T13:33:52+00:00 Arnd Bergmann arnd@arndb.de 2016-03-14T14:18:38+00:00 f7e72ebbd67551fd1ba00f387f5dc14e5f8e8c14 commit 8e0cc8c326d99e41468c96fea9785ab78883a281 upstream. gcc points out code that is not indented the way it is interpreted: net/caif/cfpkt_skbuff.c: In function 'cfpkt_setlen': net/caif/cfpkt_skbuff.c:289:4: error: statement is indented as if it were guarded by... [-Werror=misleading-indentation] return cfpkt_getlen(pkt); ^~~~~~ net/caif/cfpkt_skbuff.c:286:3: note: ...this 'else' clause, but it is not else ^~~~ It is clear from the context that not returning here would be a bug, as we'd end up passing a negative length into a function that takes a u16 length, so it is not missing curly braces here, and I'm assuming that the indentation is the only part that's wrong about it. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 8e0cc8c326d99e41468c96fea9785ab78883a281 upstream.

gcc points out code that is not indented the way it is
interpreted:

net/caif/cfpkt_skbuff.c: In function 'cfpkt_setlen':
net/caif/cfpkt_skbuff.c:289:4: error: statement is indented as if it were guarded by... [-Werror=misleading-indentation]
    return cfpkt_getlen(pkt);
    ^~~~~~
net/caif/cfpkt_skbuff.c:286:3: note: ...this 'else' clause, but it is not
   else
   ^~~~

It is clear from the context that not returning here would be
a bug, as we'd end up passing a negative length into a function
that takes a u16 length, so it is not missing curly braces
here, and I'm assuming that the indentation is the only part
that's wrong about it.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
packet: in packet_do_bind, test fanout with bind_lock held 2017-11-11T13:33:38+00:00 Willem de Bruijn willemb@google.com 2017-09-26T16:19:37+00:00 70abad3796f52ed593d5d31bf9f0b5410a522548 commit 4971613c1639d8e5f102c4e797c3bf8f83a5a69e upstream. Once a socket has po->fanout set, it remains a member of the group until it is destroyed. The prot_hook must be constant and identical across sockets in the group. If fanout_add races with packet_do_bind between the test of po->fanout and taking the lock, the bind call may make type or dev inconsistent with that of the fanout group. Hold po->bind_lock when testing po->fanout to avoid this race. I had to introduce artificial delay (local_bh_enable) to actually observe the race. Fixes: dc99f600698d ("packet: Add fanout support.") Signed-off-by: Willem de Bruijn <willemb@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 4971613c1639d8e5f102c4e797c3bf8f83a5a69e upstream.

Once a socket has po->fanout set, it remains a member of the group
until it is destroyed. The prot_hook must be constant and identical
across sockets in the group.

If fanout_add races with packet_do_bind between the test of po->fanout
and taking the lock, the bind call may make type or dev inconsistent
with that of the fanout group.

Hold po->bind_lock when testing po->fanout to avoid this race.

I had to introduce artificial delay (local_bh_enable) to actually
observe the race.

Fixes: dc99f600698d ("packet: Add fanout support.")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
packet: hold bind lock when rebinding to fanout hook 2017-11-11T13:33:38+00:00 Willem de Bruijn willemb@google.com 2017-09-14T21:14:41+00:00 4839233c04cd9ffb65fa00bdb473cbdac427d45f commit 008ba2a13f2d04c947adc536d19debb8fe66f110 upstream. Packet socket bind operations must hold the po->bind_lock. This keeps po->running consistent with whether the socket is actually on a ptype list to receive packets. fanout_add unbinds a socket and its packet_rcv/tpacket_rcv call, then binds the fanout object to receive through packet_rcv_fanout. Make it hold the po->bind_lock when testing po->running and rebinding. Else, it can race with other rebind operations, such as that in packet_set_ring from packet_rcv to tpacket_rcv. Concurrent updates can result in a socket being added to a fanout group twice, causing use-after-free KASAN bug reports, among others. Reported independently by both trinity and syzkaller. Verified that the syzkaller reproducer passes after this patch. Fixes: dc99f600698d ("packet: Add fanout support.") Reported-by: nixioaming <nixiaoming@huawei.com> Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.16: use atomic_read() not refcount_read()] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 008ba2a13f2d04c947adc536d19debb8fe66f110 upstream.

Packet socket bind operations must hold the po->bind_lock. This keeps
po->running consistent with whether the socket is actually on a ptype
list to receive packets.

fanout_add unbinds a socket and its packet_rcv/tpacket_rcv call, then
binds the fanout object to receive through packet_rcv_fanout.

Make it hold the po->bind_lock when testing po->running and rebinding.
Else, it can race with other rebind operations, such as that in
packet_set_ring from packet_rcv to tpacket_rcv. Concurrent updates
can result in a socket being added to a fanout group twice, causing
use-after-free KASAN bug reports, among others.

Reported independently by both trinity and syzkaller.
Verified that the syzkaller reproducer passes after this patch.

Fixes: dc99f600698d ("packet: Add fanout support.")
Reported-by: nixioaming <nixiaoming@huawei.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16: use atomic_read() not refcount_read()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
mac80211: accept key reinstall without changing anything 2017-11-11T13:33:38+00:00 Johannes Berg johannes.berg@intel.com 2017-09-05T12:54:54+00:00 a0a8a11d1630cd648dc1ce86da620b4e240e0315 commit fdf7cb4185b60c68e1a75e61691c4afdc15dea0e upstream. When a key is reinstalled we can reset the replay counters etc. which can lead to nonce reuse and/or replay detection being impossible, breaking security properties, as described in the "KRACK attacks". In particular, CVE-2017-13080 applies to GTK rekeying that happened in firmware while the host is in D3, with the second part of the attack being done after the host wakes up. In this case, the wpa_supplicant mitigation isn't sufficient since wpa_supplicant doesn't know the GTK material. In case this happens, simply silently accept the new key coming from userspace but don't take any action on it since it's the same key; this keeps the PN replay counters intact. Signed-off-by: Johannes Berg <johannes.berg@intel.com> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit fdf7cb4185b60c68e1a75e61691c4afdc15dea0e upstream.

When a key is reinstalled we can reset the replay counters
etc. which can lead to nonce reuse and/or replay detection
being impossible, breaking security properties, as described
in the "KRACK attacks".

In particular, CVE-2017-13080 applies to GTK rekeying that
happened in firmware while the host is in D3, with the second
part of the attack being done after the host wakes up. In
this case, the wpa_supplicant mitigation isn't sufficient
since wpa_supplicant doesn't know the GTK material.

In case this happens, simply silently accept the new key
coming from userspace but don't take any action on it since
it's the same key; this keeps the PN replay counters intact.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
sch_tbf: fix two null pointer dereferences on init failure 2017-11-11T13:33:36+00:00 Nikolay Aleksandrov nikolay@cumulusnetworks.com 2017-08-30T09:49:05+00:00 76fb491fac59fd94e17b5615250701e6f57af2de commit c2d6511e6a4f1f3673d711569c00c3849549e9b0 upstream. sch_tbf calls qdisc_watchdog_cancel() in both its ->reset and ->destroy callbacks but it may fail before the timer is initialized due to missing options (either not supplied by user-space or set as a default qdisc), also q->qdisc is used by ->reset and ->destroy so we need it initialized. Reproduce: $ sysctl net.core.default_qdisc=tbf $ ip l set ethX up Crash log: [ 959.160172] BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 [ 959.160323] IP: qdisc_reset+0xa/0x5c [ 959.160400] PGD 59cdb067 [ 959.160401] P4D 59cdb067 [ 959.160466] PUD 59ccb067 [ 959.160532] PMD 0 [ 959.160597] [ 959.160706] Oops: 0000 [#1] SMP [ 959.160778] Modules linked in: sch_tbf sch_sfb sch_prio sch_netem [ 959.160891] CPU: 2 PID: 1562 Comm: ip Not tainted 4.13.0-rc6+ #62 [ 959.160998] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014 [ 959.161157] task: ffff880059c9a700 task.stack: ffff8800376d0000 [ 959.161263] RIP: 0010:qdisc_reset+0xa/0x5c [ 959.161347] RSP: 0018:ffff8800376d3610 EFLAGS: 00010286 [ 959.161531] RAX: ffffffffa001b1dd RBX: ffff8800373a2800 RCX: 0000000000000000 [ 959.161733] RDX: ffffffff8215f160 RSI: ffffffff8215f160 RDI: 0000000000000000 [ 959.161939] RBP: ffff8800376d3618 R08: 00000000014080c0 R09: 00000000ffffffff [ 959.162141] R10: ffff8800376d3578 R11: 0000000000000020 R12: ffffffffa001d2c0 [ 959.162343] R13: ffff880037538000 R14: 00000000ffffffff R15: 0000000000000001 [ 959.162546] FS: 00007fcc5126b740(0000) GS:ffff88005d900000(0000) knlGS:0000000000000000 [ 959.162844] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 959.163030] CR2: 0000000000000018 CR3: 000000005abc4000 CR4: 00000000000406e0 [ 959.163233] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 959.163436] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 959.163638] Call Trace: [ 959.163788] tbf_reset+0x19/0x64 [sch_tbf] [ 959.163957] qdisc_destroy+0x8b/0xe5 [ 959.164119] qdisc_create_dflt+0x86/0x94 [ 959.164284] ? dev_activate+0x129/0x129 [ 959.164449] attach_one_default_qdisc+0x36/0x63 [ 959.164623] netdev_for_each_tx_queue+0x3d/0x48 [ 959.164795] dev_activate+0x4b/0x129 [ 959.164957] __dev_open+0xe7/0x104 [ 959.165118] __dev_change_flags+0xc6/0x15c [ 959.165287] dev_change_flags+0x25/0x59 [ 959.165451] do_setlink+0x30c/0xb3f [ 959.165613] ? check_chain_key+0xb0/0xfd [ 959.165782] rtnl_newlink+0x3a4/0x729 [ 959.165947] ? rtnl_newlink+0x117/0x729 [ 959.166121] ? ns_capable_common+0xd/0xb1 [ 959.166288] ? ns_capable+0x13/0x15 [ 959.166450] rtnetlink_rcv_msg+0x188/0x197 [ 959.166617] ? rcu_read_unlock+0x3e/0x5f [ 959.166783] ? rtnl_newlink+0x729/0x729 [ 959.166948] netlink_rcv_skb+0x6c/0xce [ 959.167113] rtnetlink_rcv+0x23/0x2a [ 959.167273] netlink_unicast+0x103/0x181 [ 959.167439] netlink_sendmsg+0x326/0x337 [ 959.167607] sock_sendmsg_nosec+0x14/0x3f [ 959.167772] sock_sendmsg+0x29/0x2e [ 959.167932] ___sys_sendmsg+0x209/0x28b [ 959.168098] ? do_raw_spin_unlock+0xcd/0xf8 [ 959.168267] ? _raw_spin_unlock+0x27/0x31 [ 959.168432] ? __handle_mm_fault+0x651/0xdb1 [ 959.168602] ? check_chain_key+0xb0/0xfd [ 959.168773] __sys_sendmsg+0x45/0x63 [ 959.168934] ? __sys_sendmsg+0x45/0x63 [ 959.169100] SyS_sendmsg+0x19/0x1b [ 959.169260] entry_SYSCALL_64_fastpath+0x23/0xc2 [ 959.169432] RIP: 0033:0x7fcc5097e690 [ 959.169592] RSP: 002b:00007ffd0d5c7b48 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 959.169887] RAX: ffffffffffffffda RBX: ffffffff810d278c RCX: 00007fcc5097e690 [ 959.170089] RDX: 0000000000000000 RSI: 00007ffd0d5c7b90 RDI: 0000000000000003 [ 959.170292] RBP: ffff8800376d3f98 R08: 0000000000000001 R09: 0000000000000003 [ 959.170494] R10: 00007ffd0d5c7910 R11: 0000000000000246 R12: 0000000000000006 [ 959.170697] R13: 000000000066f1a0 R14: 00007ffd0d5cfc40 R15: 0000000000000000 [ 959.170900] ? trace_hardirqs_off_caller+0xa7/0xcf [ 959.171076] Code: 00 41 c7 84 24 14 01 00 00 00 00 00 00 41 c7 84 24 98 00 00 00 00 00 00 00 41 5c 41 5d 41 5e 5d c3 66 66 66 66 90 55 48 89 e5 53 <48> 8b 47 18 48 89 fb 48 8b 40 48 48 85 c0 74 02 ff d0 48 8b bb [ 959.171637] RIP: qdisc_reset+0xa/0x5c RSP: ffff8800376d3610 [ 959.171821] CR2: 0000000000000018 Fixes: 87b60cfacf9f ("net_sched: fix error recovery at qdisc creation") Fixes: 0fbbeb1ba43b ("[PKT_SCHED]: Fix missing qdisc_destroy() in qdisc_create_dflt()") Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit c2d6511e6a4f1f3673d711569c00c3849549e9b0 upstream.

sch_tbf calls qdisc_watchdog_cancel() in both its ->reset and ->destroy
callbacks but it may fail before the timer is initialized due to missing
options (either not supplied by user-space or set as a default qdisc),
also q->qdisc is used by ->reset and ->destroy so we need it initialized.

Reproduce:
$ sysctl net.core.default_qdisc=tbf
$ ip l set ethX up

Crash log:
[  959.160172] BUG: unable to handle kernel NULL pointer dereference at 0000000000000018
[  959.160323] IP: qdisc_reset+0xa/0x5c
[  959.160400] PGD 59cdb067
[  959.160401] P4D 59cdb067
[  959.160466] PUD 59ccb067
[  959.160532] PMD 0
[  959.160597]
[  959.160706] Oops: 0000 [#1] SMP
[  959.160778] Modules linked in: sch_tbf sch_sfb sch_prio sch_netem
[  959.160891] CPU: 2 PID: 1562 Comm: ip Not tainted 4.13.0-rc6+ #62
[  959.160998] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014
[  959.161157] task: ffff880059c9a700 task.stack: ffff8800376d0000
[  959.161263] RIP: 0010:qdisc_reset+0xa/0x5c
[  959.161347] RSP: 0018:ffff8800376d3610 EFLAGS: 00010286
[  959.161531] RAX: ffffffffa001b1dd RBX: ffff8800373a2800 RCX: 0000000000000000
[  959.161733] RDX: ffffffff8215f160 RSI: ffffffff8215f160 RDI: 0000000000000000
[  959.161939] RBP: ffff8800376d3618 R08: 00000000014080c0 R09: 00000000ffffffff
[  959.162141] R10: ffff8800376d3578 R11: 0000000000000020 R12: ffffffffa001d2c0
[  959.162343] R13: ffff880037538000 R14: 00000000ffffffff R15: 0000000000000001
[  959.162546] FS:  00007fcc5126b740(0000) GS:ffff88005d900000(0000) knlGS:0000000000000000
[  959.162844] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  959.163030] CR2: 0000000000000018 CR3: 000000005abc4000 CR4: 00000000000406e0
[  959.163233] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  959.163436] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  959.163638] Call Trace:
[  959.163788]  tbf_reset+0x19/0x64 [sch_tbf]
[  959.163957]  qdisc_destroy+0x8b/0xe5
[  959.164119]  qdisc_create_dflt+0x86/0x94
[  959.164284]  ? dev_activate+0x129/0x129
[  959.164449]  attach_one_default_qdisc+0x36/0x63
[  959.164623]  netdev_for_each_tx_queue+0x3d/0x48
[  959.164795]  dev_activate+0x4b/0x129
[  959.164957]  __dev_open+0xe7/0x104
[  959.165118]  __dev_change_flags+0xc6/0x15c
[  959.165287]  dev_change_flags+0x25/0x59
[  959.165451]  do_setlink+0x30c/0xb3f
[  959.165613]  ? check_chain_key+0xb0/0xfd
[  959.165782]  rtnl_newlink+0x3a4/0x729
[  959.165947]  ? rtnl_newlink+0x117/0x729
[  959.166121]  ? ns_capable_common+0xd/0xb1
[  959.166288]  ? ns_capable+0x13/0x15
[  959.166450]  rtnetlink_rcv_msg+0x188/0x197
[  959.166617]  ? rcu_read_unlock+0x3e/0x5f
[  959.166783]  ? rtnl_newlink+0x729/0x729
[  959.166948]  netlink_rcv_skb+0x6c/0xce
[  959.167113]  rtnetlink_rcv+0x23/0x2a
[  959.167273]  netlink_unicast+0x103/0x181
[  959.167439]  netlink_sendmsg+0x326/0x337
[  959.167607]  sock_sendmsg_nosec+0x14/0x3f
[  959.167772]  sock_sendmsg+0x29/0x2e
[  959.167932]  ___sys_sendmsg+0x209/0x28b
[  959.168098]  ? do_raw_spin_unlock+0xcd/0xf8
[  959.168267]  ? _raw_spin_unlock+0x27/0x31
[  959.168432]  ? __handle_mm_fault+0x651/0xdb1
[  959.168602]  ? check_chain_key+0xb0/0xfd
[  959.168773]  __sys_sendmsg+0x45/0x63
[  959.168934]  ? __sys_sendmsg+0x45/0x63
[  959.169100]  SyS_sendmsg+0x19/0x1b
[  959.169260]  entry_SYSCALL_64_fastpath+0x23/0xc2
[  959.169432] RIP: 0033:0x7fcc5097e690
[  959.169592] RSP: 002b:00007ffd0d5c7b48 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[  959.169887] RAX: ffffffffffffffda RBX: ffffffff810d278c RCX: 00007fcc5097e690
[  959.170089] RDX: 0000000000000000 RSI: 00007ffd0d5c7b90 RDI: 0000000000000003
[  959.170292] RBP: ffff8800376d3f98 R08: 0000000000000001 R09: 0000000000000003
[  959.170494] R10: 00007ffd0d5c7910 R11: 0000000000000246 R12: 0000000000000006
[  959.170697] R13: 000000000066f1a0 R14: 00007ffd0d5cfc40 R15: 0000000000000000
[  959.170900]  ? trace_hardirqs_off_caller+0xa7/0xcf
[  959.171076] Code: 00 41 c7 84 24 14 01 00 00 00 00 00 00 41 c7 84 24
98 00 00 00 00 00 00 00 41 5c 41 5d 41 5e 5d c3 66 66 66 66 90 55 48 89
e5 53 <48> 8b 47 18 48 89 fb 48 8b 40 48 48 85 c0 74 02 ff d0 48 8b bb
[  959.171637] RIP: qdisc_reset+0xa/0x5c RSP: ffff8800376d3610
[  959.171821] CR2: 0000000000000018

Fixes: 87b60cfacf9f ("net_sched: fix error recovery at qdisc creation")
Fixes: 0fbbeb1ba43b ("[PKT_SCHED]: Fix missing qdisc_destroy() in qdisc_create_dflt()")
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
sch_netem: avoid null pointer deref on init failure 2017-11-11T13:33:35+00:00 Nikolay Aleksandrov nikolay@cumulusnetworks.com 2017-08-30T09:49:03+00:00 0ff978e604aaea9cadd885bd12df2e4538198f97 commit 634576a1844dba15bc5e6fc61d72f37e13a21615 upstream. netem can fail in ->init due to missing options (either not supplied by user-space or used as a default qdisc) causing a timer->base null pointer deref in its ->destroy() and ->reset() callbacks. Reproduce: $ sysctl net.core.default_qdisc=netem $ ip l set ethX up Crash log: [ 1814.846943] BUG: unable to handle kernel NULL pointer dereference at (null) [ 1814.847181] IP: hrtimer_active+0x17/0x8a [ 1814.847270] PGD 59c34067 [ 1814.847271] P4D 59c34067 [ 1814.847337] PUD 37374067 [ 1814.847403] PMD 0 [ 1814.847468] [ 1814.847582] Oops: 0000 [#1] SMP [ 1814.847655] Modules linked in: sch_netem(O) sch_fq_codel(O) [ 1814.847761] CPU: 3 PID: 1573 Comm: ip Tainted: G O 4.13.0-rc6+ #62 [ 1814.847884] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014 [ 1814.848043] task: ffff88003723a700 task.stack: ffff88005adc8000 [ 1814.848235] RIP: 0010:hrtimer_active+0x17/0x8a [ 1814.848407] RSP: 0018:ffff88005adcb590 EFLAGS: 00010246 [ 1814.848590] RAX: 0000000000000000 RBX: ffff880058e359d8 RCX: 0000000000000000 [ 1814.848793] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff880058e359d8 [ 1814.848998] RBP: ffff88005adcb5b0 R08: 00000000014080c0 R09: 00000000ffffffff [ 1814.849204] R10: ffff88005adcb660 R11: 0000000000000020 R12: 0000000000000000 [ 1814.849410] R13: ffff880058e359d8 R14: 00000000ffffffff R15: 0000000000000001 [ 1814.849616] FS: 00007f733bbca740(0000) GS:ffff88005d980000(0000) knlGS:0000000000000000 [ 1814.849919] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1814.850107] CR2: 0000000000000000 CR3: 0000000059f0d000 CR4: 00000000000406e0 [ 1814.850313] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 1814.850518] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 1814.850723] Call Trace: [ 1814.850875] hrtimer_try_to_cancel+0x1a/0x93 [ 1814.851047] hrtimer_cancel+0x15/0x20 [ 1814.851211] qdisc_watchdog_cancel+0x12/0x14 [ 1814.851383] netem_reset+0xe6/0xed [sch_netem] [ 1814.851561] qdisc_destroy+0x8b/0xe5 [ 1814.851723] qdisc_create_dflt+0x86/0x94 [ 1814.851890] ? dev_activate+0x129/0x129 [ 1814.852057] attach_one_default_qdisc+0x36/0x63 [ 1814.852232] netdev_for_each_tx_queue+0x3d/0x48 [ 1814.852406] dev_activate+0x4b/0x129 [ 1814.852569] __dev_open+0xe7/0x104 [ 1814.852730] __dev_change_flags+0xc6/0x15c [ 1814.852899] dev_change_flags+0x25/0x59 [ 1814.853064] do_setlink+0x30c/0xb3f [ 1814.853228] ? check_chain_key+0xb0/0xfd [ 1814.853396] ? check_chain_key+0xb0/0xfd [ 1814.853565] rtnl_newlink+0x3a4/0x729 [ 1814.853728] ? rtnl_newlink+0x117/0x729 [ 1814.853905] ? ns_capable_common+0xd/0xb1 [ 1814.854072] ? ns_capable+0x13/0x15 [ 1814.854234] rtnetlink_rcv_msg+0x188/0x197 [ 1814.854404] ? rcu_read_unlock+0x3e/0x5f [ 1814.854572] ? rtnl_newlink+0x729/0x729 [ 1814.854737] netlink_rcv_skb+0x6c/0xce [ 1814.854902] rtnetlink_rcv+0x23/0x2a [ 1814.855064] netlink_unicast+0x103/0x181 [ 1814.855230] netlink_sendmsg+0x326/0x337 [ 1814.855398] sock_sendmsg_nosec+0x14/0x3f [ 1814.855584] sock_sendmsg+0x29/0x2e [ 1814.855747] ___sys_sendmsg+0x209/0x28b [ 1814.855912] ? do_raw_spin_unlock+0xcd/0xf8 [ 1814.856082] ? _raw_spin_unlock+0x27/0x31 [ 1814.856251] ? __handle_mm_fault+0x651/0xdb1 [ 1814.856421] ? check_chain_key+0xb0/0xfd [ 1814.856592] __sys_sendmsg+0x45/0x63 [ 1814.856755] ? __sys_sendmsg+0x45/0x63 [ 1814.856923] SyS_sendmsg+0x19/0x1b [ 1814.857083] entry_SYSCALL_64_fastpath+0x23/0xc2 [ 1814.857256] RIP: 0033:0x7f733b2dd690 [ 1814.857419] RSP: 002b:00007ffe1d3387d8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 1814.858238] RAX: ffffffffffffffda RBX: ffffffff810d278c RCX: 00007f733b2dd690 [ 1814.858445] RDX: 0000000000000000 RSI: 00007ffe1d338820 RDI: 0000000000000003 [ 1814.858651] RBP: ffff88005adcbf98 R08: 0000000000000001 R09: 0000000000000003 [ 1814.858856] R10: 00007ffe1d3385a0 R11: 0000000000000246 R12: 0000000000000002 [ 1814.859060] R13: 000000000066f1a0 R14: 00007ffe1d3408d0 R15: 0000000000000000 [ 1814.859267] ? trace_hardirqs_off_caller+0xa7/0xcf [ 1814.859446] Code: 10 55 48 89 c7 48 89 e5 e8 45 a1 fb ff 31 c0 5d c3 31 c0 c3 66 66 66 66 90 55 48 89 e5 41 56 41 55 41 54 53 49 89 fd 49 8b 45 30 <4c> 8b 20 41 8b 5c 24 38 31 c9 31 d2 48 c7 c7 50 8e 1d 82 41 89 [ 1814.860022] RIP: hrtimer_active+0x17/0x8a RSP: ffff88005adcb590 [ 1814.860214] CR2: 0000000000000000 Fixes: 87b60cfacf9f ("net_sched: fix error recovery at qdisc creation") Fixes: 0fbbeb1ba43b ("[PKT_SCHED]: Fix missing qdisc_destroy() in qdisc_create_dflt()") Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 634576a1844dba15bc5e6fc61d72f37e13a21615 upstream.

netem can fail in ->init due to missing options (either not supplied by
user-space or used as a default qdisc) causing a timer->base null
pointer deref in its ->destroy() and ->reset() callbacks.

Reproduce:
$ sysctl net.core.default_qdisc=netem
$ ip l set ethX up

Crash log:
[ 1814.846943] BUG: unable to handle kernel NULL pointer dereference at (null)
[ 1814.847181] IP: hrtimer_active+0x17/0x8a
[ 1814.847270] PGD 59c34067
[ 1814.847271] P4D 59c34067
[ 1814.847337] PUD 37374067
[ 1814.847403] PMD 0
[ 1814.847468]
[ 1814.847582] Oops: 0000 [#1] SMP
[ 1814.847655] Modules linked in: sch_netem(O) sch_fq_codel(O)
[ 1814.847761] CPU: 3 PID: 1573 Comm: ip Tainted: G           O 4.13.0-rc6+ #62
[ 1814.847884] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014
[ 1814.848043] task: ffff88003723a700 task.stack: ffff88005adc8000
[ 1814.848235] RIP: 0010:hrtimer_active+0x17/0x8a
[ 1814.848407] RSP: 0018:ffff88005adcb590 EFLAGS: 00010246
[ 1814.848590] RAX: 0000000000000000 RBX: ffff880058e359d8 RCX: 0000000000000000
[ 1814.848793] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff880058e359d8
[ 1814.848998] RBP: ffff88005adcb5b0 R08: 00000000014080c0 R09: 00000000ffffffff
[ 1814.849204] R10: ffff88005adcb660 R11: 0000000000000020 R12: 0000000000000000
[ 1814.849410] R13: ffff880058e359d8 R14: 00000000ffffffff R15: 0000000000000001
[ 1814.849616] FS:  00007f733bbca740(0000) GS:ffff88005d980000(0000) knlGS:0000000000000000
[ 1814.849919] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1814.850107] CR2: 0000000000000000 CR3: 0000000059f0d000 CR4: 00000000000406e0
[ 1814.850313] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 1814.850518] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 1814.850723] Call Trace:
[ 1814.850875]  hrtimer_try_to_cancel+0x1a/0x93
[ 1814.851047]  hrtimer_cancel+0x15/0x20
[ 1814.851211]  qdisc_watchdog_cancel+0x12/0x14
[ 1814.851383]  netem_reset+0xe6/0xed [sch_netem]
[ 1814.851561]  qdisc_destroy+0x8b/0xe5
[ 1814.851723]  qdisc_create_dflt+0x86/0x94
[ 1814.851890]  ? dev_activate+0x129/0x129
[ 1814.852057]  attach_one_default_qdisc+0x36/0x63
[ 1814.852232]  netdev_for_each_tx_queue+0x3d/0x48
[ 1814.852406]  dev_activate+0x4b/0x129
[ 1814.852569]  __dev_open+0xe7/0x104
[ 1814.852730]  __dev_change_flags+0xc6/0x15c
[ 1814.852899]  dev_change_flags+0x25/0x59
[ 1814.853064]  do_setlink+0x30c/0xb3f
[ 1814.853228]  ? check_chain_key+0xb0/0xfd
[ 1814.853396]  ? check_chain_key+0xb0/0xfd
[ 1814.853565]  rtnl_newlink+0x3a4/0x729
[ 1814.853728]  ? rtnl_newlink+0x117/0x729
[ 1814.853905]  ? ns_capable_common+0xd/0xb1
[ 1814.854072]  ? ns_capable+0x13/0x15
[ 1814.854234]  rtnetlink_rcv_msg+0x188/0x197
[ 1814.854404]  ? rcu_read_unlock+0x3e/0x5f
[ 1814.854572]  ? rtnl_newlink+0x729/0x729
[ 1814.854737]  netlink_rcv_skb+0x6c/0xce
[ 1814.854902]  rtnetlink_rcv+0x23/0x2a
[ 1814.855064]  netlink_unicast+0x103/0x181
[ 1814.855230]  netlink_sendmsg+0x326/0x337
[ 1814.855398]  sock_sendmsg_nosec+0x14/0x3f
[ 1814.855584]  sock_sendmsg+0x29/0x2e
[ 1814.855747]  ___sys_sendmsg+0x209/0x28b
[ 1814.855912]  ? do_raw_spin_unlock+0xcd/0xf8
[ 1814.856082]  ? _raw_spin_unlock+0x27/0x31
[ 1814.856251]  ? __handle_mm_fault+0x651/0xdb1
[ 1814.856421]  ? check_chain_key+0xb0/0xfd
[ 1814.856592]  __sys_sendmsg+0x45/0x63
[ 1814.856755]  ? __sys_sendmsg+0x45/0x63
[ 1814.856923]  SyS_sendmsg+0x19/0x1b
[ 1814.857083]  entry_SYSCALL_64_fastpath+0x23/0xc2
[ 1814.857256] RIP: 0033:0x7f733b2dd690
[ 1814.857419] RSP: 002b:00007ffe1d3387d8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[ 1814.858238] RAX: ffffffffffffffda RBX: ffffffff810d278c RCX: 00007f733b2dd690
[ 1814.858445] RDX: 0000000000000000 RSI: 00007ffe1d338820 RDI: 0000000000000003
[ 1814.858651] RBP: ffff88005adcbf98 R08: 0000000000000001 R09: 0000000000000003
[ 1814.858856] R10: 00007ffe1d3385a0 R11: 0000000000000246 R12: 0000000000000002
[ 1814.859060] R13: 000000000066f1a0 R14: 00007ffe1d3408d0 R15: 0000000000000000
[ 1814.859267]  ? trace_hardirqs_off_caller+0xa7/0xcf
[ 1814.859446] Code: 10 55 48 89 c7 48 89 e5 e8 45 a1 fb ff 31 c0 5d c3
31 c0 c3 66 66 66 66 90 55 48 89 e5 41 56 41 55 41 54 53 49 89 fd 49 8b
45 30 <4c> 8b 20 41 8b 5c 24 38 31 c9 31 d2 48 c7 c7 50 8e 1d 82 41 89
[ 1814.860022] RIP: hrtimer_active+0x17/0x8a RSP: ffff88005adcb590
[ 1814.860214] CR2: 0000000000000000

Fixes: 87b60cfacf9f ("net_sched: fix error recovery at qdisc creation")
Fixes: 0fbbeb1ba43b ("[PKT_SCHED]: Fix missing qdisc_destroy() in qdisc_create_dflt()")
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
sch_fq_codel: avoid double free on init failure 2017-11-11T13:33:35+00:00 Nikolay Aleksandrov nikolay@cumulusnetworks.com 2017-08-30T09:49:02+00:00 191fd165da1de27a2a61267f18eb65419ea938d5 commit 30c31d746d0eb458ae327f522bc8e4c44cbea0f0 upstream. It is very unlikely to happen but the backlogs memory allocation could fail and will free q->flows, but then ->destroy() will free q->flows too. For correctness remove the first free and let ->destroy clean up. Fixes: 87b60cfacf9f ("net_sched: fix error recovery at qdisc creation") Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.16: fq_codel used different alloc/free functions] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 30c31d746d0eb458ae327f522bc8e4c44cbea0f0 upstream.

It is very unlikely to happen but the backlogs memory allocation
could fail and will free q->flows, but then ->destroy() will free
q->flows too. For correctness remove the first free and let ->destroy
clean up.

Fixes: 87b60cfacf9f ("net_sched: fix error recovery at qdisc creation")
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16: fq_codel used different alloc/free functions]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
sch_cbq: fix null pointer dereferences on init failure 2017-11-11T13:33:35+00:00 Nikolay Aleksandrov nikolay@cumulusnetworks.com 2017-08-30T09:49:01+00:00 addb3a32b0ed9de074b9c84b094b060141fcfa94 commit 3501d059921246ff617b43e86250a719c140bd97 upstream. CBQ can fail on ->init by wrong nl attributes or simply for missing any, f.e. if it's set as a default qdisc then TCA_OPTIONS (opt) will be NULL when it is activated. The first thing init does is parse opt but it will dereference a null pointer if used as a default qdisc, also since init failure at default qdisc invokes ->reset() which cancels all timers then we'll also dereference two more null pointers (timer->base) as they were never initialized. To reproduce: $ sysctl net.core.default_qdisc=cbq $ ip l set ethX up Crash log of the first null ptr deref: [44727.907454] BUG: unable to handle kernel NULL pointer dereference at (null) [44727.907600] IP: cbq_init+0x27/0x205 [44727.907676] PGD 59ff4067 [44727.907677] P4D 59ff4067 [44727.907742] PUD 59c70067 [44727.907807] PMD 0 [44727.907873] [44727.907982] Oops: 0000 [#1] SMP [44727.908054] Modules linked in: [44727.908126] CPU: 1 PID: 21312 Comm: ip Not tainted 4.13.0-rc6+ #60 [44727.908235] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014 [44727.908477] task: ffff88005ad42700 task.stack: ffff880037214000 [44727.908672] RIP: 0010:cbq_init+0x27/0x205 [44727.908838] RSP: 0018:ffff8800372175f0 EFLAGS: 00010286 [44727.909018] RAX: ffffffff816c3852 RBX: ffff880058c53800 RCX: 0000000000000000 [44727.909222] RDX: 0000000000000004 RSI: 0000000000000000 RDI: ffff8800372175f8 [44727.909427] RBP: ffff880037217650 R08: ffffffff81b0f380 R09: 0000000000000000 [44727.909631] R10: ffff880037217660 R11: 0000000000000020 R12: ffffffff822a44c0 [44727.909835] R13: ffff880058b92000 R14: 00000000ffffffff R15: 0000000000000001 [44727.910040] FS: 00007ff8bc583740(0000) GS:ffff88005d880000(0000) knlGS:0000000000000000 [44727.910339] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [44727.910525] CR2: 0000000000000000 CR3: 00000000371e5000 CR4: 00000000000406e0 [44727.910731] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [44727.910936] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [44727.911141] Call Trace: [44727.911291] ? lockdep_init_map+0xb6/0x1ba [44727.911461] ? qdisc_alloc+0x14e/0x187 [44727.911626] qdisc_create_dflt+0x7a/0x94 [44727.911794] ? dev_activate+0x129/0x129 [44727.911959] attach_one_default_qdisc+0x36/0x63 [44727.912132] netdev_for_each_tx_queue+0x3d/0x48 [44727.912305] dev_activate+0x4b/0x129 [44727.912468] __dev_open+0xe7/0x104 [44727.912631] __dev_change_flags+0xc6/0x15c [44727.912799] dev_change_flags+0x25/0x59 [44727.912966] do_setlink+0x30c/0xb3f [44727.913129] ? check_chain_key+0xb0/0xfd [44727.913294] ? check_chain_key+0xb0/0xfd [44727.913463] rtnl_newlink+0x3a4/0x729 [44727.913626] ? rtnl_newlink+0x117/0x729 [44727.913801] ? ns_capable_common+0xd/0xb1 [44727.913968] ? ns_capable+0x13/0x15 [44727.914131] rtnetlink_rcv_msg+0x188/0x197 [44727.914300] ? rcu_read_unlock+0x3e/0x5f [44727.914465] ? rtnl_newlink+0x729/0x729 [44727.914630] netlink_rcv_skb+0x6c/0xce [44727.914796] rtnetlink_rcv+0x23/0x2a [44727.914956] netlink_unicast+0x103/0x181 [44727.915122] netlink_sendmsg+0x326/0x337 [44727.915291] sock_sendmsg_nosec+0x14/0x3f [44727.915459] sock_sendmsg+0x29/0x2e [44727.915619] ___sys_sendmsg+0x209/0x28b [44727.915784] ? do_raw_spin_unlock+0xcd/0xf8 [44727.915954] ? _raw_spin_unlock+0x27/0x31 [44727.916121] ? __handle_mm_fault+0x651/0xdb1 [44727.916290] ? check_chain_key+0xb0/0xfd [44727.916461] __sys_sendmsg+0x45/0x63 [44727.916626] ? __sys_sendmsg+0x45/0x63 [44727.916792] SyS_sendmsg+0x19/0x1b [44727.916950] entry_SYSCALL_64_fastpath+0x23/0xc2 [44727.917125] RIP: 0033:0x7ff8bbc96690 [44727.917286] RSP: 002b:00007ffc360991e8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [44727.917579] RAX: ffffffffffffffda RBX: ffffffff810d278c RCX: 00007ff8bbc96690 [44727.917783] RDX: 0000000000000000 RSI: 00007ffc36099230 RDI: 0000000000000003 [44727.917987] RBP: ffff880037217f98 R08: 0000000000000001 R09: 0000000000000003 [44727.918190] R10: 00007ffc36098fb0 R11: 0000000000000246 R12: 0000000000000006 [44727.918393] R13: 000000000066f1a0 R14: 00007ffc360a12e0 R15: 0000000000000000 [44727.918597] ? trace_hardirqs_off_caller+0xa7/0xcf [44727.918774] Code: 41 5f 5d c3 66 66 66 66 90 55 48 8d 56 04 45 31 c9 49 c7 c0 80 f3 b0 81 48 89 e5 41 55 41 54 53 48 89 fb 48 8d 7d a8 48 83 ec 48 <0f> b7 0e be 07 00 00 00 83 e9 04 e8 e6 f7 d8 ff 85 c0 0f 88 bb [44727.919332] RIP: cbq_init+0x27/0x205 RSP: ffff8800372175f0 [44727.919516] CR2: 0000000000000000 Fixes: 0fbbeb1ba43b ("[PKT_SCHED]: Fix missing qdisc_destroy() in qdisc_create_dflt()") Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.16: - Keep using HRTIMER_MODE_ABS - Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 3501d059921246ff617b43e86250a719c140bd97 upstream.

CBQ can fail on ->init by wrong nl attributes or simply for missing any,
f.e. if it's set as a default qdisc then TCA_OPTIONS (opt) will be NULL
when it is activated. The first thing init does is parse opt but it will
dereference a null pointer if used as a default qdisc, also since init
failure at default qdisc invokes ->reset() which cancels all timers then
we'll also dereference two more null pointers (timer->base) as they were
never initialized.

To reproduce:
$ sysctl net.core.default_qdisc=cbq
$ ip l set ethX up

Crash log of the first null ptr deref:
[44727.907454] BUG: unable to handle kernel NULL pointer dereference at (null)
[44727.907600] IP: cbq_init+0x27/0x205
[44727.907676] PGD 59ff4067
[44727.907677] P4D 59ff4067
[44727.907742] PUD 59c70067
[44727.907807] PMD 0
[44727.907873]
[44727.907982] Oops: 0000 [#1] SMP
[44727.908054] Modules linked in:
[44727.908126] CPU: 1 PID: 21312 Comm: ip Not tainted 4.13.0-rc6+ #60
[44727.908235] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014
[44727.908477] task: ffff88005ad42700 task.stack: ffff880037214000
[44727.908672] RIP: 0010:cbq_init+0x27/0x205
[44727.908838] RSP: 0018:ffff8800372175f0 EFLAGS: 00010286
[44727.909018] RAX: ffffffff816c3852 RBX: ffff880058c53800 RCX: 0000000000000000
[44727.909222] RDX: 0000000000000004 RSI: 0000000000000000 RDI: ffff8800372175f8
[44727.909427] RBP: ffff880037217650 R08: ffffffff81b0f380 R09: 0000000000000000
[44727.909631] R10: ffff880037217660 R11: 0000000000000020 R12: ffffffff822a44c0
[44727.909835] R13: ffff880058b92000 R14: 00000000ffffffff R15: 0000000000000001
[44727.910040] FS:  00007ff8bc583740(0000) GS:ffff88005d880000(0000) knlGS:0000000000000000
[44727.910339] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[44727.910525] CR2: 0000000000000000 CR3: 00000000371e5000 CR4: 00000000000406e0
[44727.910731] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[44727.910936] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[44727.911141] Call Trace:
[44727.911291]  ? lockdep_init_map+0xb6/0x1ba
[44727.911461]  ? qdisc_alloc+0x14e/0x187
[44727.911626]  qdisc_create_dflt+0x7a/0x94
[44727.911794]  ? dev_activate+0x129/0x129
[44727.911959]  attach_one_default_qdisc+0x36/0x63
[44727.912132]  netdev_for_each_tx_queue+0x3d/0x48
[44727.912305]  dev_activate+0x4b/0x129
[44727.912468]  __dev_open+0xe7/0x104
[44727.912631]  __dev_change_flags+0xc6/0x15c
[44727.912799]  dev_change_flags+0x25/0x59
[44727.912966]  do_setlink+0x30c/0xb3f
[44727.913129]  ? check_chain_key+0xb0/0xfd
[44727.913294]  ? check_chain_key+0xb0/0xfd
[44727.913463]  rtnl_newlink+0x3a4/0x729
[44727.913626]  ? rtnl_newlink+0x117/0x729
[44727.913801]  ? ns_capable_common+0xd/0xb1
[44727.913968]  ? ns_capable+0x13/0x15
[44727.914131]  rtnetlink_rcv_msg+0x188/0x197
[44727.914300]  ? rcu_read_unlock+0x3e/0x5f
[44727.914465]  ? rtnl_newlink+0x729/0x729
[44727.914630]  netlink_rcv_skb+0x6c/0xce
[44727.914796]  rtnetlink_rcv+0x23/0x2a
[44727.914956]  netlink_unicast+0x103/0x181
[44727.915122]  netlink_sendmsg+0x326/0x337
[44727.915291]  sock_sendmsg_nosec+0x14/0x3f
[44727.915459]  sock_sendmsg+0x29/0x2e
[44727.915619]  ___sys_sendmsg+0x209/0x28b
[44727.915784]  ? do_raw_spin_unlock+0xcd/0xf8
[44727.915954]  ? _raw_spin_unlock+0x27/0x31
[44727.916121]  ? __handle_mm_fault+0x651/0xdb1
[44727.916290]  ? check_chain_key+0xb0/0xfd
[44727.916461]  __sys_sendmsg+0x45/0x63
[44727.916626]  ? __sys_sendmsg+0x45/0x63
[44727.916792]  SyS_sendmsg+0x19/0x1b
[44727.916950]  entry_SYSCALL_64_fastpath+0x23/0xc2
[44727.917125] RIP: 0033:0x7ff8bbc96690
[44727.917286] RSP: 002b:00007ffc360991e8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[44727.917579] RAX: ffffffffffffffda RBX: ffffffff810d278c RCX: 00007ff8bbc96690
[44727.917783] RDX: 0000000000000000 RSI: 00007ffc36099230 RDI: 0000000000000003
[44727.917987] RBP: ffff880037217f98 R08: 0000000000000001 R09: 0000000000000003
[44727.918190] R10: 00007ffc36098fb0 R11: 0000000000000246 R12: 0000000000000006
[44727.918393] R13: 000000000066f1a0 R14: 00007ffc360a12e0 R15: 0000000000000000
[44727.918597]  ? trace_hardirqs_off_caller+0xa7/0xcf
[44727.918774] Code: 41 5f 5d c3 66 66 66 66 90 55 48 8d 56 04 45 31 c9
49 c7 c0 80 f3 b0 81 48 89 e5 41 55 41 54 53 48 89 fb 48 8d 7d a8 48 83
ec 48 <0f> b7 0e be 07 00 00 00 83 e9 04 e8 e6 f7 d8 ff 85 c0 0f 88 bb
[44727.919332] RIP: cbq_init+0x27/0x205 RSP: ffff8800372175f0
[44727.919516] CR2: 0000000000000000

Fixes: 0fbbeb1ba43b ("[PKT_SCHED]: Fix missing qdisc_destroy() in qdisc_create_dflt()")
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16:
 - Keep using HRTIMER_MODE_ABS
 - Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>