linux-stable.git/net/ipv6, branch v3.18.49 Linux kernel stable tree dccp/tcp: fix routing redirect race 2017-04-18T05:55:54+00:00 Jon Maxwell jmaxwell37@gmail.com 2017-03-10T05:40:33+00:00 d01d1106dd58661705e7b2289c9fceb4d02fa4e4 commit 45caeaa5ac0b4b11784ac6f932c0ad4c6b67cda0 upstream. As Eric Dumazet pointed out this also needs to be fixed in IPv6. v2: Contains the IPv6 tcp/Ipv6 dccp patches as well. We have seen a few incidents lately where a dst_enty has been freed with a dangling TCP socket reference (sk->sk_dst_cache) pointing to that dst_entry. If the conditions/timings are right a crash then ensues when the freed dst_entry is referenced later on. A Common crashing back trace is: #8 [] page_fault at ffffffff8163e648 [exception RIP: __tcp_ack_snd_check+74] . . #9 [] tcp_rcv_established at ffffffff81580b64 #10 [] tcp_v4_do_rcv at ffffffff8158b54a #11 [] tcp_v4_rcv at ffffffff8158cd02 #12 [] ip_local_deliver_finish at ffffffff815668f4 #13 [] ip_local_deliver at ffffffff81566bd9 #14 [] ip_rcv_finish at ffffffff8156656d #15 [] ip_rcv at ffffffff81566f06 #16 [] __netif_receive_skb_core at ffffffff8152b3a2 #17 [] __netif_receive_skb at ffffffff8152b608 #18 [] netif_receive_skb at ffffffff8152b690 #19 [] vmxnet3_rq_rx_complete at ffffffffa015eeaf [vmxnet3] #20 [] vmxnet3_poll_rx_only at ffffffffa015f32a [vmxnet3] #21 [] net_rx_action at ffffffff8152bac2 #22 [] __do_softirq at ffffffff81084b4f #23 [] call_softirq at ffffffff8164845c #24 [] do_softirq at ffffffff81016fc5 #25 [] irq_exit at ffffffff81084ee5 #26 [] do_IRQ at ffffffff81648ff8 Of course it may happen with other NIC drivers as well. It's found the freed dst_entry here: 224 static bool tcp_in_quickack_mode(struct sock *sk)↩ 225 {↩ 226 ▹ const struct inet_connection_sock *icsk = inet_csk(sk);↩ 227 ▹ const struct dst_entry *dst = __sk_dst_get(sk);↩ 228 ↩ 229 ▹ return (dst && dst_metric(dst, RTAX_QUICKACK)) ||↩ 230 ▹ ▹ (icsk->icsk_ack.quick && !icsk->icsk_ack.pingpong);↩ 231 }↩ But there are other backtraces attributed to the same freed dst_entry in netfilter code as well. All the vmcores showed 2 significant clues: - Remote hosts behind the default gateway had always been redirected to a different gateway. A rtable/dst_entry will be added for that host. Making more dst_entrys with lower reference counts. Making this more probable. - All vmcores showed a postitive LockDroppedIcmps value, e.g: LockDroppedIcmps 267 A closer look at the tcp_v4_err() handler revealed that do_redirect() will run regardless of whether user space has the socket locked. This can result in a race condition where the same dst_entry cached in sk->sk_dst_entry can be decremented twice for the same socket via: do_redirect()->__sk_dst_check()-> dst_release(). Which leads to the dst_entry being prematurely freed with another socket pointing to it via sk->sk_dst_cache and a subsequent crash. To fix this skip do_redirect() if usespace has the socket locked. Instead let the redirect take place later when user space does not have the socket locked. The dccp/IPv6 code is very similar in this respect, so fixing it there too. As Eric Garver pointed out the following commit now invalidates routes. Which can set the dst->obsolete flag so that ipv4_dst_check() returns null and triggers the dst_release(). Fixes: ceb3320610d6 ("ipv4: Kill routes during PMTU/redirect updates.") Cc: Eric Garver <egarver@redhat.com> Cc: Hannes Sowa <hsowa@redhat.com> Signed-off-by: Jon Maxwell <jmaxwell37@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 45caeaa5ac0b4b11784ac6f932c0ad4c6b67cda0 upstream.

As Eric Dumazet pointed out this also needs to be fixed in IPv6.
v2: Contains the IPv6 tcp/Ipv6 dccp patches as well.

We have seen a few incidents lately where a dst_enty has been freed
with a dangling TCP socket reference (sk->sk_dst_cache) pointing to that
dst_entry. If the conditions/timings are right a crash then ensues when the
freed dst_entry is referenced later on. A Common crashing back trace is:

 #8 [] page_fault at ffffffff8163e648
    [exception RIP: __tcp_ack_snd_check+74]
.
.
 #9 [] tcp_rcv_established at ffffffff81580b64
#10 [] tcp_v4_do_rcv at ffffffff8158b54a
#11 [] tcp_v4_rcv at ffffffff8158cd02
#12 [] ip_local_deliver_finish at ffffffff815668f4
#13 [] ip_local_deliver at ffffffff81566bd9
#14 [] ip_rcv_finish at ffffffff8156656d
#15 [] ip_rcv at ffffffff81566f06
#16 [] __netif_receive_skb_core at ffffffff8152b3a2
#17 [] __netif_receive_skb at ffffffff8152b608
#18 [] netif_receive_skb at ffffffff8152b690
#19 [] vmxnet3_rq_rx_complete at ffffffffa015eeaf [vmxnet3]
#20 [] vmxnet3_poll_rx_only at ffffffffa015f32a [vmxnet3]
#21 [] net_rx_action at ffffffff8152bac2
#22 [] __do_softirq at ffffffff81084b4f
#23 [] call_softirq at ffffffff8164845c
#24 [] do_softirq at ffffffff81016fc5
#25 [] irq_exit at ffffffff81084ee5
#26 [] do_IRQ at ffffffff81648ff8

Of course it may happen with other NIC drivers as well.

It's found the freed dst_entry here:

 224 static bool tcp_in_quickack_mode(struct sock *sk)↩
 225 {↩
 226 ▹       const struct inet_connection_sock *icsk = inet_csk(sk);↩
 227 ▹       const struct dst_entry *dst = __sk_dst_get(sk);↩
 228 ↩
 229 ▹       return (dst && dst_metric(dst, RTAX_QUICKACK)) ||↩
 230 ▹       ▹       (icsk->icsk_ack.quick && !icsk->icsk_ack.pingpong);↩
 231 }↩

But there are other backtraces attributed to the same freed dst_entry in
netfilter code as well.

All the vmcores showed 2 significant clues:

- Remote hosts behind the default gateway had always been redirected to a
different gateway. A rtable/dst_entry will be added for that host. Making
more dst_entrys with lower reference counts. Making this more probable.

- All vmcores showed a postitive LockDroppedIcmps value, e.g:

LockDroppedIcmps                  267

A closer look at the tcp_v4_err() handler revealed that do_redirect() will run
regardless of whether user space has the socket locked. This can result in a
race condition where the same dst_entry cached in sk->sk_dst_entry can be
decremented twice for the same socket via:

do_redirect()->__sk_dst_check()-> dst_release().

Which leads to the dst_entry being prematurely freed with another socket
pointing to it via sk->sk_dst_cache and a subsequent crash.

To fix this skip do_redirect() if usespace has the socket locked. Instead let
the redirect take place later when user space does not have the socket
locked.

The dccp/IPv6 code is very similar in this respect, so fixing it there too.

As Eric Garver pointed out the following commit now invalidates routes. Which
can set the dst->obsolete flag so that ipv4_dst_check() returns null and
triggers the dst_release().

Fixes: ceb3320610d6 ("ipv4: Kill routes during PMTU/redirect updates.")
Cc: Eric Garver <egarver@redhat.com>
Cc: Hannes Sowa <hsowa@redhat.com>
Signed-off-by: Jon Maxwell <jmaxwell37@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vti6: return GRE_KEY for vti6 2017-04-18T05:55:51+00:00 David Forster dforster@brocade.com 2017-02-24T14:20:32+00:00 629d9888cc0996cc012d8666e8250f5878cdd02b commit 7dcdf941cdc96692ab99fd790c8cc68945514851 upstream. Align vti6 with vti by returning GRE_KEY flag. This enables iproute2 to display tunnel keys on "ip -6 tunnel show" Signed-off-by: David Forster <dforster@brocade.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 7dcdf941cdc96692ab99fd790c8cc68945514851 upstream.

Align vti6 with vti by returning GRE_KEY flag. This enables iproute2
to display tunnel keys on "ip -6 tunnel show"

Signed-off-by: David Forster <dforster@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipv6: correctly add local routes when lo goes up 2017-04-18T05:55:46+00:00 Nicolas Dichtel nicolas.dichtel@6wind.com 2016-10-12T08:10:40+00:00 a04b12a185e448e4f0a52814a12ba937b10a1a6f [ Upstream commit a220445f9f4382c36a53d8ef3e08165fa27f7e2c ] The goal of the patch is to fix this scenario: ip link add dummy1 type dummy ip link set dummy1 up ip link set lo down ; ip link set lo up After that sequence, the local route to the link layer address of dummy1 is not there anymore. When the loopback is set down, all local routes are deleted by addrconf_ifdown()/rt6_ifdown(). At this time, the rt6_info entry still exists, because the corresponding idev has a reference on it. After the rcu grace period, dst_rcu_free() is called, and thus ___dst_free(), which will set obsolete to DST_OBSOLETE_DEAD. In this case, init_loopback() is called before dst_rcu_free(), thus obsolete is still sets to something <= 0. So, the function doesn't add the route again. To avoid that race, let's check the rt6 refcnt instead. Fixes: 25fb6ca4ed9c ("net IPv6 : Fix broken IPv6 routing table after loopback down-up") Fixes: a881ae1f625c ("ipv6: don't call addrconf_dst_alloc again when enable lo") Fixes: 33d99113b110 ("ipv6: reallocate addrconf router for ipv6 address when lo device up") Reported-by: Francesco Santoro <francesco.santoro@6wind.com> Reported-by: Samuel Gauthier <samuel.gauthier@6wind.com> CC: Balakumaran Kannan <Balakumaran.Kannan@ap.sony.com> CC: Maruthi Thotad <Maruthi.Thotad@ap.sony.com> CC: Sabrina Dubroca <sd@queasysnail.net> CC: Hannes Frederic Sowa <hannes@stressinduktion.org> CC: Weilong Chen <chenweilong@huawei.com> CC: Gao feng <gaofeng@cn.fujitsu.com> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit a220445f9f4382c36a53d8ef3e08165fa27f7e2c ]

The goal of the patch is to fix this scenario:
 ip link add dummy1 type dummy
 ip link set dummy1 up
 ip link set lo down ; ip link set lo up

After that sequence, the local route to the link layer address of dummy1 is
not there anymore.

When the loopback is set down, all local routes are deleted by
addrconf_ifdown()/rt6_ifdown(). At this time, the rt6_info entry still
exists, because the corresponding idev has a reference on it. After the rcu
grace period, dst_rcu_free() is called, and thus ___dst_free(), which will
set obsolete to DST_OBSOLETE_DEAD.

In this case, init_loopback() is called before dst_rcu_free(), thus
obsolete is still sets to something <= 0. So, the function doesn't add the
route again. To avoid that race, let's check the rt6 refcnt instead.

Fixes: 25fb6ca4ed9c ("net IPv6 : Fix broken IPv6 routing table after loopback down-up")
Fixes: a881ae1f625c ("ipv6: don't call addrconf_dst_alloc again when enable lo")
Fixes: 33d99113b110 ("ipv6: reallocate addrconf router for ipv6 address when lo device up")
Reported-by: Francesco Santoro <francesco.santoro@6wind.com>
Reported-by: Samuel Gauthier <samuel.gauthier@6wind.com>
CC: Balakumaran Kannan <Balakumaran.Kannan@ap.sony.com>
CC: Maruthi Thotad <Maruthi.Thotad@ap.sony.com>
CC: Sabrina Dubroca <sd@queasysnail.net>
CC: Hannes Frederic Sowa <hannes@stressinduktion.org>
CC: Weilong Chen <chenweilong@huawei.com>
CC: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipmr, ip6mr: fix scheduling while atomic and a deadlock with ipmr_get_route 2017-04-18T05:55:46+00:00 Nikolay Aleksandrov nikolay@cumulusnetworks.com 2016-09-25T21:08:31+00:00 ad7db1290185be22dfcf13261ffcedd4409abfdb [ Upstream commit 2cf750704bb6d7ed8c7d732e071dd1bc890ea5e8 ] Since the commit below the ipmr/ip6mr rtnl_unicast() code uses the portid instead of the previous dst_pid which was copied from in_skb's portid. Since the skb is new the portid is 0 at that point so the packets are sent to the kernel and we get scheduling while atomic or a deadlock (depending on where it happens) by trying to acquire rtnl two times. Also since this is RTM_GETROUTE, it can be triggered by a normal user. Here's the sleeping while atomic trace: [ 7858.212557] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:620 [ 7858.212748] in_atomic(): 1, irqs_disabled(): 0, pid: 0, name: swapper/0 [ 7858.212881] 2 locks held by swapper/0/0: [ 7858.213013] #0: (((&mrt->ipmr_expire_timer))){+.-...}, at: [<ffffffff810fbbf5>] call_timer_fn+0x5/0x350 [ 7858.213422] #1: (mfc_unres_lock){+.....}, at: [<ffffffff8161e005>] ipmr_expire_process+0x25/0x130 [ 7858.213807] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.8.0-rc7+ #179 [ 7858.213934] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014 [ 7858.214108] 0000000000000000 ffff88005b403c50 ffffffff813a7804 0000000000000000 [ 7858.214412] ffffffff81a1338e ffff88005b403c78 ffffffff810a4a72 ffffffff81a1338e [ 7858.214716] 000000000000026c 0000000000000000 ffff88005b403ca8 ffffffff810a4b9f [ 7858.215251] Call Trace: [ 7858.215412] <IRQ> [<ffffffff813a7804>] dump_stack+0x85/0xc1 [ 7858.215662] [<ffffffff810a4a72>] ___might_sleep+0x192/0x250 [ 7858.215868] [<ffffffff810a4b9f>] __might_sleep+0x6f/0x100 [ 7858.216072] [<ffffffff8165bea3>] mutex_lock_nested+0x33/0x4d0 [ 7858.216279] [<ffffffff815a7a5f>] ? netlink_lookup+0x25f/0x460 [ 7858.216487] [<ffffffff8157474b>] rtnetlink_rcv+0x1b/0x40 [ 7858.216687] [<ffffffff815a9a0c>] netlink_unicast+0x19c/0x260 [ 7858.216900] [<ffffffff81573c70>] rtnl_unicast+0x20/0x30 [ 7858.217128] [<ffffffff8161cd39>] ipmr_destroy_unres+0xa9/0xf0 [ 7858.217351] [<ffffffff8161e06f>] ipmr_expire_process+0x8f/0x130 [ 7858.217581] [<ffffffff8161dfe0>] ? ipmr_net_init+0x180/0x180 [ 7858.217785] [<ffffffff8161dfe0>] ? ipmr_net_init+0x180/0x180 [ 7858.217990] [<ffffffff810fbc95>] call_timer_fn+0xa5/0x350 [ 7858.218192] [<ffffffff810fbbf5>] ? call_timer_fn+0x5/0x350 [ 7858.218415] [<ffffffff8161dfe0>] ? ipmr_net_init+0x180/0x180 [ 7858.218656] [<ffffffff810fde10>] run_timer_softirq+0x260/0x640 [ 7858.218865] [<ffffffff8166379b>] ? __do_softirq+0xbb/0x54f [ 7858.219068] [<ffffffff816637c8>] __do_softirq+0xe8/0x54f [ 7858.219269] [<ffffffff8107a948>] irq_exit+0xb8/0xc0 [ 7858.219463] [<ffffffff81663452>] smp_apic_timer_interrupt+0x42/0x50 [ 7858.219678] [<ffffffff816625bc>] apic_timer_interrupt+0x8c/0xa0 [ 7858.219897] <EOI> [<ffffffff81055f16>] ? native_safe_halt+0x6/0x10 [ 7858.220165] [<ffffffff810d64dd>] ? trace_hardirqs_on+0xd/0x10 [ 7858.220373] [<ffffffff810298e3>] default_idle+0x23/0x190 [ 7858.220574] [<ffffffff8102a20f>] arch_cpu_idle+0xf/0x20 [ 7858.220790] [<ffffffff810c9f8c>] default_idle_call+0x4c/0x60 [ 7858.221016] [<ffffffff810ca33b>] cpu_startup_entry+0x39b/0x4d0 [ 7858.221257] [<ffffffff8164f995>] rest_init+0x135/0x140 [ 7858.221469] [<ffffffff81f83014>] start_kernel+0x50e/0x51b [ 7858.221670] [<ffffffff81f82120>] ? early_idt_handler_array+0x120/0x120 [ 7858.221894] [<ffffffff81f8243f>] x86_64_start_reservations+0x2a/0x2c [ 7858.222113] [<ffffffff81f8257c>] x86_64_start_kernel+0x13b/0x14a Fixes: 2942e9005056 ("[RTNETLINK]: Use rtnl_unicast() for rtnetlink unicasts") Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 2cf750704bb6d7ed8c7d732e071dd1bc890ea5e8 ]

Since the commit below the ipmr/ip6mr rtnl_unicast() code uses the portid
instead of the previous dst_pid which was copied from in_skb's portid.
Since the skb is new the portid is 0 at that point so the packets are sent
to the kernel and we get scheduling while atomic or a deadlock (depending
on where it happens) by trying to acquire rtnl two times.
Also since this is RTM_GETROUTE, it can be triggered by a normal user.

Here's the sleeping while atomic trace:
[ 7858.212557] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:620
[ 7858.212748] in_atomic(): 1, irqs_disabled(): 0, pid: 0, name: swapper/0
[ 7858.212881] 2 locks held by swapper/0/0:
[ 7858.213013]  #0:  (((&mrt->ipmr_expire_timer))){+.-...}, at: [<ffffffff810fbbf5>] call_timer_fn+0x5/0x350
[ 7858.213422]  #1:  (mfc_unres_lock){+.....}, at: [<ffffffff8161e005>] ipmr_expire_process+0x25/0x130
[ 7858.213807] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.8.0-rc7+ #179
[ 7858.213934] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014
[ 7858.214108]  0000000000000000 ffff88005b403c50 ffffffff813a7804 0000000000000000
[ 7858.214412]  ffffffff81a1338e ffff88005b403c78 ffffffff810a4a72 ffffffff81a1338e
[ 7858.214716]  000000000000026c 0000000000000000 ffff88005b403ca8 ffffffff810a4b9f
[ 7858.215251] Call Trace:
[ 7858.215412]  <IRQ>  [<ffffffff813a7804>] dump_stack+0x85/0xc1
[ 7858.215662]  [<ffffffff810a4a72>] ___might_sleep+0x192/0x250
[ 7858.215868]  [<ffffffff810a4b9f>] __might_sleep+0x6f/0x100
[ 7858.216072]  [<ffffffff8165bea3>] mutex_lock_nested+0x33/0x4d0
[ 7858.216279]  [<ffffffff815a7a5f>] ? netlink_lookup+0x25f/0x460
[ 7858.216487]  [<ffffffff8157474b>] rtnetlink_rcv+0x1b/0x40
[ 7858.216687]  [<ffffffff815a9a0c>] netlink_unicast+0x19c/0x260
[ 7858.216900]  [<ffffffff81573c70>] rtnl_unicast+0x20/0x30
[ 7858.217128]  [<ffffffff8161cd39>] ipmr_destroy_unres+0xa9/0xf0
[ 7858.217351]  [<ffffffff8161e06f>] ipmr_expire_process+0x8f/0x130
[ 7858.217581]  [<ffffffff8161dfe0>] ? ipmr_net_init+0x180/0x180
[ 7858.217785]  [<ffffffff8161dfe0>] ? ipmr_net_init+0x180/0x180
[ 7858.217990]  [<ffffffff810fbc95>] call_timer_fn+0xa5/0x350
[ 7858.218192]  [<ffffffff810fbbf5>] ? call_timer_fn+0x5/0x350
[ 7858.218415]  [<ffffffff8161dfe0>] ? ipmr_net_init+0x180/0x180
[ 7858.218656]  [<ffffffff810fde10>] run_timer_softirq+0x260/0x640
[ 7858.218865]  [<ffffffff8166379b>] ? __do_softirq+0xbb/0x54f
[ 7858.219068]  [<ffffffff816637c8>] __do_softirq+0xe8/0x54f
[ 7858.219269]  [<ffffffff8107a948>] irq_exit+0xb8/0xc0
[ 7858.219463]  [<ffffffff81663452>] smp_apic_timer_interrupt+0x42/0x50
[ 7858.219678]  [<ffffffff816625bc>] apic_timer_interrupt+0x8c/0xa0
[ 7858.219897]  <EOI>  [<ffffffff81055f16>] ? native_safe_halt+0x6/0x10
[ 7858.220165]  [<ffffffff810d64dd>] ? trace_hardirqs_on+0xd/0x10
[ 7858.220373]  [<ffffffff810298e3>] default_idle+0x23/0x190
[ 7858.220574]  [<ffffffff8102a20f>] arch_cpu_idle+0xf/0x20
[ 7858.220790]  [<ffffffff810c9f8c>] default_idle_call+0x4c/0x60
[ 7858.221016]  [<ffffffff810ca33b>] cpu_startup_entry+0x39b/0x4d0
[ 7858.221257]  [<ffffffff8164f995>] rest_init+0x135/0x140
[ 7858.221469]  [<ffffffff81f83014>] start_kernel+0x50e/0x51b
[ 7858.221670]  [<ffffffff81f82120>] ? early_idt_handler_array+0x120/0x120
[ 7858.221894]  [<ffffffff81f8243f>] x86_64_start_reservations+0x2a/0x2c
[ 7858.222113]  [<ffffffff81f8257c>] x86_64_start_kernel+0x13b/0x14a

Fixes: 2942e9005056 ("[RTNETLINK]: Use rtnl_unicast() for rtnetlink unicasts")
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ip6_gre: fix flowi6_proto value in ip6gre_xmit_other() 2017-04-18T05:55:46+00:00 Lance Richardson lrichard@redhat.com 2016-09-23T19:50:29+00:00 00a677b683f1a78e4007e2de8267dc025a109ea1 [ Upstream commit db32e4e49ce2b0e5fcc17803d011a401c0a637f6 ] Similar to commit 3be07244b733 ("ip6_gre: fix flowi6_proto value in xmit path"), set flowi6_proto to IPPROTO_GRE for output route lookup. Up until now, ip6gre_xmit_other() has set flowi6_proto to a bogus value. This affected output route lookup for packets sent on an ip6gretap device in cases where routing was dependent on the value of flowi6_proto. Since the correct proto is already set in the tunnel flowi6 template via commit 252f3f5a1189 ("ip6_gre: Set flowi6_proto as IPPROTO_GRE in xmit path."), simply delete the line setting the incorrect flowi6_proto value. Suggested-by: Jiri Benc <jbenc@redhat.com> Fixes: c12b395a4664 ("gre: Support GRE over IPv6") Reviewed-by: Shmulik Ladkani <shmulik.ladkani@gmail.com> Signed-off-by: Lance Richardson <lrichard@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit db32e4e49ce2b0e5fcc17803d011a401c0a637f6 ]

Similar to commit 3be07244b733 ("ip6_gre: fix flowi6_proto value in
xmit path"), set flowi6_proto to IPPROTO_GRE for output route lookup.

Up until now, ip6gre_xmit_other() has set flowi6_proto to a bogus value.
This affected output route lookup for packets sent on an ip6gretap device
in cases where routing was dependent on the value of flowi6_proto.

Since the correct proto is already set in the tunnel flowi6 template via
commit 252f3f5a1189 ("ip6_gre: Set flowi6_proto as IPPROTO_GRE in xmit
path."), simply delete the line setting the incorrect flowi6_proto value.

Suggested-by: Jiri Benc <jbenc@redhat.com>
Fixes: c12b395a4664 ("gre: Support GRE over IPv6")
Reviewed-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Signed-off-by: Lance Richardson <lrichard@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipv6: tcp: add a missing tcp_v6_restore_cb() 2017-04-18T05:55:44+00:00 Eric Dumazet edumazet@google.com 2017-02-06T04:23:22+00:00 c12d69340ee7cd97da07cc8549b7f08bbaae71af [ Upstream commit ebf6c9cb23d7e56eec8575a88071dec97ad5c6e2 ] Dmitry reported use-after-free in ip6_datagram_recv_specific_ctl() A similar bug was fixed in commit 8ce48623f0cf ("ipv6: tcp: restore IP6CB for pktoptions skbs"), but I missed another spot. tcp_v6_syn_recv_sock() can indeed set np->pktoptions from ireq->pktopts Fixes: 971f10eca186 ("tcp: better TCP_SKB_CB layout to reduce cache line misses") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit ebf6c9cb23d7e56eec8575a88071dec97ad5c6e2 ]

Dmitry reported use-after-free in ip6_datagram_recv_specific_ctl()

A similar bug was fixed in commit 8ce48623f0cf ("ipv6: tcp: restore
IP6CB for pktoptions skbs"), but I missed another spot.

tcp_v6_syn_recv_sock() can indeed set np->pktoptions from ireq->pktopts

Fixes: 971f10eca186 ("tcp: better TCP_SKB_CB layout to reduce cache line misses")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipv6: tcp: restore IP6CB for pktoptions skbs 2017-04-18T05:55:44+00:00 Eric Dumazet edumazet@google.com 2016-10-12T17:01:45+00:00 00f1069e680ec0311a5af1aa4f7ff77cecc90769 [ Upstream commit 8ce48623f0cf3d632e32448411feddccb693d351 ] Baozeng Ding reported following KASAN splat : BUG: KASAN: use-after-free in ip6_datagram_recv_specific_ctl+0x13f1/0x15c0 at addr ffff880029c84ec8 Read of size 1 by task poc/25548 Call Trace: [<ffffffff82cf43c9>] dump_stack+0x12e/0x185 /lib/dump_stack.c:15 [< inline >] print_address_description /mm/kasan/report.c:204 [<ffffffff817ced3b>] kasan_report_error+0x48b/0x4b0 /mm/kasan/report.c:283 [< inline >] kasan_report /mm/kasan/report.c:303 [<ffffffff817ced9e>] __asan_report_load1_noabort+0x3e/0x40 /mm/kasan/report.c:321 [<ffffffff85c71da1>] ip6_datagram_recv_specific_ctl+0x13f1/0x15c0 /net/ipv6/datagram.c:687 [<ffffffff85c734c3>] ip6_datagram_recv_ctl+0x33/0x40 [<ffffffff85c0b07c>] do_ipv6_getsockopt.isra.4+0xaec/0x2150 [<ffffffff85c0c7f6>] ipv6_getsockopt+0x116/0x230 [<ffffffff859b5a12>] tcp_getsockopt+0x82/0xd0 /net/ipv4/tcp.c:3035 [<ffffffff855fb385>] sock_common_getsockopt+0x95/0xd0 /net/core/sock.c:2647 [< inline >] SYSC_getsockopt /net/socket.c:1776 [<ffffffff855f8ba2>] SyS_getsockopt+0x142/0x230 /net/socket.c:1758 [<ffffffff8685cdc5>] entry_SYSCALL_64_fastpath+0x23/0xc6 Memory state around the buggy address: ffff880029c84d80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff880029c84e00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff > ffff880029c84e80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff880029c84f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff880029c84f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff He also provided a syzkaller reproducer. Issue is that ip6_datagram_recv_specific_ctl() expects to find IP6CB data that was moved at a different place in tcp_v6_rcv() This patch moves tcp_v6_restore_cb() up and calls it from tcp_v6_do_rcv() when np->pktoptions is set. Fixes: 971f10eca186 ("tcp: better TCP_SKB_CB layout to reduce cache line misses") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Baozeng Ding <sploving1@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 8ce48623f0cf3d632e32448411feddccb693d351 ]

Baozeng Ding reported following KASAN splat :

BUG: KASAN: use-after-free in ip6_datagram_recv_specific_ctl+0x13f1/0x15c0 at addr ffff880029c84ec8
Read of size 1 by task poc/25548
Call Trace:
 [<ffffffff82cf43c9>] dump_stack+0x12e/0x185 /lib/dump_stack.c:15
 [<     inline     >] print_address_description /mm/kasan/report.c:204
 [<ffffffff817ced3b>] kasan_report_error+0x48b/0x4b0 /mm/kasan/report.c:283
 [<     inline     >] kasan_report /mm/kasan/report.c:303
 [<ffffffff817ced9e>] __asan_report_load1_noabort+0x3e/0x40 /mm/kasan/report.c:321
 [<ffffffff85c71da1>] ip6_datagram_recv_specific_ctl+0x13f1/0x15c0 /net/ipv6/datagram.c:687
 [<ffffffff85c734c3>] ip6_datagram_recv_ctl+0x33/0x40
 [<ffffffff85c0b07c>] do_ipv6_getsockopt.isra.4+0xaec/0x2150
 [<ffffffff85c0c7f6>] ipv6_getsockopt+0x116/0x230
 [<ffffffff859b5a12>] tcp_getsockopt+0x82/0xd0 /net/ipv4/tcp.c:3035
 [<ffffffff855fb385>] sock_common_getsockopt+0x95/0xd0 /net/core/sock.c:2647
 [<     inline     >] SYSC_getsockopt /net/socket.c:1776
 [<ffffffff855f8ba2>] SyS_getsockopt+0x142/0x230 /net/socket.c:1758
 [<ffffffff8685cdc5>] entry_SYSCALL_64_fastpath+0x23/0xc6
Memory state around the buggy address:
 ffff880029c84d80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff880029c84e00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
> ffff880029c84e80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                              ^
 ffff880029c84f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff880029c84f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff

He also provided a syzkaller reproducer.

Issue is that ip6_datagram_recv_specific_ctl() expects to find IP6CB
data that was moved at a different place in tcp_v6_rcv()

This patch moves tcp_v6_restore_cb() up and calls it from
tcp_v6_do_rcv() when np->pktoptions is set.

Fixes: 971f10eca186 ("tcp: better TCP_SKB_CB layout to reduce cache line misses")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Baozeng Ding <sploving1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ip6_gre: fix ip6gre_err() invalid reads 2017-04-18T05:55:44+00:00 Eric Dumazet edumazet@google.com 2017-02-05T07:18:55+00:00 3bbaa8061856b883c9deb16d1942188ef2608850 [ Upstream commit 7892032cfe67f4bde6fc2ee967e45a8fbaf33756 ] Andrey Konovalov reported out of bound accesses in ip6gre_err() If GRE flags contains GRE_KEY, the following expression *(((__be32 *)p) + (grehlen / 4) - 1) accesses data ~40 bytes after the expected point, since grehlen includes the size of IPv6 headers. Let's use a "struct gre_base_hdr *greh" pointer to make this code more readable. p[1] becomes greh->protocol. grhlen is the GRE header length. Fixes: c12b395a4664 ("gre: Support GRE over IPv6") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 7892032cfe67f4bde6fc2ee967e45a8fbaf33756 ]

Andrey Konovalov reported out of bound accesses in ip6gre_err()

If GRE flags contains GRE_KEY, the following expression
*(((__be32 *)p) + (grehlen / 4) - 1)

accesses data ~40 bytes after the expected point, since
grehlen includes the size of IPv6 headers.

Let's use a "struct gre_base_hdr *greh" pointer to make this
code more readable.

p[1] becomes greh->protocol.
grhlen is the GRE header length.

Fixes: c12b395a4664 ("gre: Support GRE over IPv6")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sit: fix a double free on error path 2017-04-18T05:55:44+00:00 WANG Cong xiyou.wangcong@gmail.com 2017-02-08T18:02:13+00:00 d203c93f465baa076dfe0d27ff6f869a40a1a5c7 [ Upstream commit d7426c69a1942b2b9b709bf66b944ff09f561484 ] Dmitry reported a double free in sit_init_net(): kernel BUG at mm/percpu.c:689! invalid opcode: 0000 [#1] SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 0 PID: 15692 Comm: syz-executor1 Not tainted 4.10.0-rc6-next-20170206 #1 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8801c9cc27c0 task.stack: ffff88017d1d8000 RIP: 0010:pcpu_free_area+0x68b/0x810 mm/percpu.c:689 RSP: 0018:ffff88017d1df488 EFLAGS: 00010046 RAX: 0000000000010000 RBX: 00000000000007c0 RCX: ffffc90002829000 RDX: 0000000000010000 RSI: ffffffff81940efb RDI: ffff8801db841d94 RBP: ffff88017d1df590 R08: dffffc0000000000 R09: 1ffffffff0bb3bdd R10: dffffc0000000000 R11: 00000000000135dd R12: ffff8801db841d80 R13: 0000000000038e40 R14: 00000000000007c0 R15: 00000000000007c0 FS: 00007f6ea608f700(0000) GS:ffff8801dbe00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000002000aff8 CR3: 00000001c8d44000 CR4: 00000000001426f0 DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: free_percpu+0x212/0x520 mm/percpu.c:1264 ipip6_dev_free+0x43/0x60 net/ipv6/sit.c:1335 sit_init_net+0x3cb/0xa10 net/ipv6/sit.c:1831 ops_init+0x10a/0x530 net/core/net_namespace.c:115 setup_net+0x2ed/0x690 net/core/net_namespace.c:291 copy_net_ns+0x26c/0x530 net/core/net_namespace.c:396 create_new_namespaces+0x409/0x860 kernel/nsproxy.c:106 unshare_nsproxy_namespaces+0xae/0x1e0 kernel/nsproxy.c:205 SYSC_unshare kernel/fork.c:2281 [inline] SyS_unshare+0x64e/0xfc0 kernel/fork.c:2231 entry_SYSCALL_64_fastpath+0x1f/0xc2 This is because when tunnel->dst_cache init fails, we free dev->tstats once in ipip6_tunnel_init() and twice in sit_init_net(). This looks redundant but its ndo_uinit() does not seem enough to clean up everything here. So avoid this by setting dev->tstats to NULL after the first free, at least for -net. Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit d7426c69a1942b2b9b709bf66b944ff09f561484 ]

Dmitry reported a double free in sit_init_net():

  kernel BUG at mm/percpu.c:689!
  invalid opcode: 0000 [#1] SMP KASAN
  Dumping ftrace buffer:
     (ftrace buffer empty)
  Modules linked in:
  CPU: 0 PID: 15692 Comm: syz-executor1 Not tainted 4.10.0-rc6-next-20170206 #1
  Hardware name: Google Google Compute Engine/Google Compute Engine,
  BIOS Google 01/01/2011
  task: ffff8801c9cc27c0 task.stack: ffff88017d1d8000
  RIP: 0010:pcpu_free_area+0x68b/0x810 mm/percpu.c:689
  RSP: 0018:ffff88017d1df488 EFLAGS: 00010046
  RAX: 0000000000010000 RBX: 00000000000007c0 RCX: ffffc90002829000
  RDX: 0000000000010000 RSI: ffffffff81940efb RDI: ffff8801db841d94
  RBP: ffff88017d1df590 R08: dffffc0000000000 R09: 1ffffffff0bb3bdd
  R10: dffffc0000000000 R11: 00000000000135dd R12: ffff8801db841d80
  R13: 0000000000038e40 R14: 00000000000007c0 R15: 00000000000007c0
  FS:  00007f6ea608f700(0000) GS:ffff8801dbe00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 000000002000aff8 CR3: 00000001c8d44000 CR4: 00000000001426f0
  DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
  Call Trace:
   free_percpu+0x212/0x520 mm/percpu.c:1264
   ipip6_dev_free+0x43/0x60 net/ipv6/sit.c:1335
   sit_init_net+0x3cb/0xa10 net/ipv6/sit.c:1831
   ops_init+0x10a/0x530 net/core/net_namespace.c:115
   setup_net+0x2ed/0x690 net/core/net_namespace.c:291
   copy_net_ns+0x26c/0x530 net/core/net_namespace.c:396
   create_new_namespaces+0x409/0x860 kernel/nsproxy.c:106
   unshare_nsproxy_namespaces+0xae/0x1e0 kernel/nsproxy.c:205
   SYSC_unshare kernel/fork.c:2281 [inline]
   SyS_unshare+0x64e/0xfc0 kernel/fork.c:2231
   entry_SYSCALL_64_fastpath+0x1f/0xc2

This is because when tunnel->dst_cache init fails, we free dev->tstats
once in ipip6_tunnel_init() and twice in sit_init_net(). This looks
redundant but its ndo_uinit() does not seem enough to clean up everything
here. So avoid this by setting dev->tstats to NULL after the first free,
at least for -net.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipv6: pointer math error in ip6_tnl_parse_tlv_enc_lim() 2017-04-18T05:55:43+00:00 Dan Carpenter dan.carpenter@oracle.com 2017-02-01T08:46:32+00:00 a5042c997aa4b4d20f14a5e66c73537d59a9277e [ Upstream commit 63117f09c768be05a0bf465911297dc76394f686 ] Casting is a high precedence operation but "off" and "i" are in terms of bytes so we need to have some parenthesis here. Fixes: fbfa743a9d2a ("ipv6: fix ip6_tnl_parse_tlv_enc_lim()") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 63117f09c768be05a0bf465911297dc76394f686 ]

Casting is a high precedence operation but "off" and "i" are in terms of
bytes so we need to have some parenthesis here.

Fixes: fbfa743a9d2a ("ipv6: fix ip6_tnl_parse_tlv_enc_lim()")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>