Commit Graph

40 Commits

Author SHA1 Message Date
Jakub Kicinski
dcb2a7a0d0 fib: add missing attribute validation for tun_id
[ Upstream commit 4c16d64ea04056f1b1b324ab6916019f6a064114 ]

Add missing netlink policy entry for FRA_TUN_ID.

Fixes: e7030878fc84 ("fib: Add fib rule match on tunnel id")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-07 14:11:02 +02:00
Jason Baron
8595ffe55d net: sched: correct flower port blocking
[ Upstream commit 8a9093c79863b58cc2f9874d7ae788f0d622a596 ]

tc flower rules that are based on src or dst port blocking are sometimes
ineffective due to uninitialized stack data. __skb_flow_dissect() extracts
ports from the skb for tc flower to match against. However, the port
dissection is not done when when the FLOW_DIS_IS_FRAGMENT bit is set in
key_control->flags. All callers of __skb_flow_dissect(), zero-out the
key_control field except for fl_classify() as used by the flower
classifier. Thus, the FLOW_DIS_IS_FRAGMENT may be set on entry to
__skb_flow_dissect(), since key_control is allocated on the stack
and may not be initialized.

Since key_basic and key_control are present for all flow keys, let's
make sure they are initialized.

Fixes: 62230715fd24 ("flow_dissector: do not dissect l4 ports for fragments")
Co-developed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Jason Baron <jbaron@akamai.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-07 14:04:39 +02:00
Dedy Lansky
730a475c3a cfg80211/mac80211: make ieee80211_send_layer2_update a public function
commit 30ca1aa536211f5ac3de0173513a7a99a98a97f3 upstream.

Make ieee80211_send_layer2_update() a common function so other drivers
can re-use it.

Signed-off-by: Dedy Lansky <dlansky@codeaurora.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
[bwh: Backported to 4.4 as dependency of commit 3e493173b784
 "mac80211: Do not send Layer 2 Update frame before authorization":
 - Retain type-casting of skb_put() return value
 - Adjust context]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-07 13:36:16 +02:00
Eric Dumazet
88913b39bb net: add annotations on hh->hh_len lockless accesses
[ Upstream commit c305c6ae79e2ce20c22660ceda94f0d86d639a82 ]

KCSAN reported a data-race [1]

While we can use READ_ONCE() on the read sides,
we need to make sure hh->hh_len is written last.

[1]

BUG: KCSAN: data-race in eth_header_cache / neigh_resolve_output

write to 0xffff8880b9dedcb8 of 4 bytes by task 29760 on cpu 0:
 eth_header_cache+0xa9/0xd0 net/ethernet/eth.c:247
 neigh_hh_init net/core/neighbour.c:1463 [inline]
 neigh_resolve_output net/core/neighbour.c:1480 [inline]
 neigh_resolve_output+0x415/0x470 net/core/neighbour.c:1470
 neigh_output include/net/neighbour.h:511 [inline]
 ip6_finish_output2+0x7a2/0xec0 net/ipv6/ip6_output.c:116
 __ip6_finish_output net/ipv6/ip6_output.c:142 [inline]
 __ip6_finish_output+0x2d7/0x330 net/ipv6/ip6_output.c:127
 ip6_finish_output+0x41/0x160 net/ipv6/ip6_output.c:152
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip6_output+0xf2/0x280 net/ipv6/ip6_output.c:175
 dst_output include/net/dst.h:436 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ndisc_send_skb+0x459/0x5f0 net/ipv6/ndisc.c:505
 ndisc_send_ns+0x207/0x430 net/ipv6/ndisc.c:647
 rt6_probe_deferred+0x98/0xf0 net/ipv6/route.c:615
 process_one_work+0x3d4/0x890 kernel/workqueue.c:2269
 worker_thread+0xa0/0x800 kernel/workqueue.c:2415
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

read to 0xffff8880b9dedcb8 of 4 bytes by task 29572 on cpu 1:
 neigh_resolve_output net/core/neighbour.c:1479 [inline]
 neigh_resolve_output+0x113/0x470 net/core/neighbour.c:1470
 neigh_output include/net/neighbour.h:511 [inline]
 ip6_finish_output2+0x7a2/0xec0 net/ipv6/ip6_output.c:116
 __ip6_finish_output net/ipv6/ip6_output.c:142 [inline]
 __ip6_finish_output+0x2d7/0x330 net/ipv6/ip6_output.c:127
 ip6_finish_output+0x41/0x160 net/ipv6/ip6_output.c:152
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip6_output+0xf2/0x280 net/ipv6/ip6_output.c:175
 dst_output include/net/dst.h:436 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ndisc_send_skb+0x459/0x5f0 net/ipv6/ndisc.c:505
 ndisc_send_ns+0x207/0x430 net/ipv6/ndisc.c:647
 rt6_probe_deferred+0x98/0xf0 net/ipv6/route.c:615
 process_one_work+0x3d4/0x890 kernel/workqueue.c:2269
 worker_thread+0xa0/0x800 kernel/workqueue.c:2415
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 29572 Comm: kworker/1:4 Not tainted 5.4.0-rc6+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events rt6_probe_deferred

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-07 13:25:04 +02:00
Geert Uytterhoeven
babef0270f net: dst: Force 4-byte alignment of dst_metrics
[ Upstream commit 258a980d1ec23e2c786e9536a7dd260bea74bae6 ]

When storing a pointer to a dst_metrics structure in dst_entry._metrics,
two flags are added in the least significant bits of the pointer value.
Hence this assumes all pointers to dst_metrics structures have at least
4-byte alignment.

However, on m68k, the minimum alignment of 32-bit values is 2 bytes, not
4 bytes.  Hence in some kernel builds, dst_default_metrics may be only
2-byte aligned, leading to obscure boot warnings like:

    WARNING: CPU: 0 PID: 7 at lib/refcount.c:28 refcount_warn_saturate+0x44/0x9a
    refcount_t: underflow; use-after-free.
    Modules linked in:
    CPU: 0 PID: 7 Comm: ksoftirqd/0 Tainted: G        W         5.5.0-rc2-atari-01448-g114a1a1038af891d-dirty #261
    Stack from 10835e6c:
	    10835e6c 0038134f 00023fa6 00394b0f 0000001c 00000009 00321560 00023fea
	    00394b0f 0000001c 001a70f8 00000009 00000000 10835eb4 00000001 00000000
	    04208040 0000000a 00394b4a 10835ed4 00043aa8 001a70f8 00394b0f 0000001c
	    00000009 00394b4a 0026aba8 003215a4 00000003 00000000 0026d5a8 00000001
	    003215a4 003a4361 003238d6 000001f0 00000000 003215a4 10aa3b00 00025e84
	    003ddb00 10834000 002416a8 10aa3b00 00000000 00000080 000aa038 0004854a
    Call Trace: [<00023fa6>] __warn+0xb2/0xb4
     [<00023fea>] warn_slowpath_fmt+0x42/0x64
     [<001a70f8>] refcount_warn_saturate+0x44/0x9a
     [<00043aa8>] printk+0x0/0x18
     [<001a70f8>] refcount_warn_saturate+0x44/0x9a
     [<0026aba8>] refcount_sub_and_test.constprop.73+0x38/0x3e
     [<0026d5a8>] ipv4_dst_destroy+0x5e/0x7e
     [<00025e84>] __local_bh_enable_ip+0x0/0x8e
     [<002416a8>] dst_destroy+0x40/0xae

Fix this by forcing 4-byte alignment of all dst_metrics structures.

Fixes: e5fd387ad5b30ca3 ("ipv6: do not overwrite inetpeer metrics prematurely")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-07 13:22:22 +02:00
Guillaume Nault
b4c05de502 tcp: Protect accesses to .ts_recent_stamp with {READ,WRITE}_ONCE()
[ Upstream commit 721c8dafad26ccfa90ff659ee19755e3377b829d ]

Syncookies borrow the ->rx_opt.ts_recent_stamp field to store the
timestamp of the last synflood. Protect them with READ_ONCE() and
WRITE_ONCE() since reads and writes aren't serialised.

Use of .rx_opt.ts_recent_stamp for storing the synflood timestamp was
introduced by a0f82f64e269 ("syncookies: remove last_synq_overflow from
struct tcp_sock"). But unprotected accesses were already there when
timestamp was stored in .last_synq_overflow.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-07 13:12:38 +02:00
Guillaume Nault
572fb0873b tcp: tighten acceptance of ACKs not matching a child socket
[ Upstream commit cb44a08f8647fd2e8db5cc9ac27cd8355fa392d8 ]

When no synflood occurs, the synflood timestamp isn't updated.
Therefore it can be so old that time_after32() can consider it to be
in the future.

That's a problem for tcp_synq_no_recent_overflow() as it may report
that a recent overflow occurred while, in fact, it's just that jiffies
has grown past 'last_overflow' + TCP_SYNCOOKIE_VALID + 2^31.

Spurious detection of recent overflows lead to extra syncookie
verification in cookie_v[46]_check(). At that point, the verification
should fail and the packet dropped. But we should have dropped the
packet earlier as we didn't even send a syncookie.

Let's refine tcp_synq_no_recent_overflow() to report a recent overflow
only if jiffies is within the
[last_overflow, last_overflow + TCP_SYNCOOKIE_VALID] interval. This
way, no spurious recent overflow is reported when jiffies wraps and
'last_overflow' becomes in the future from the point of view of
time_after32().

However, if jiffies wraps and enters the
[last_overflow, last_overflow + TCP_SYNCOOKIE_VALID] interval (with
'last_overflow' being a stale synflood timestamp), then
tcp_synq_no_recent_overflow() still erroneously reports an
overflow. In such cases, we have to rely on syncookie verification
to drop the packet. We unfortunately have no way to differentiate
between a fresh and a stale syncookie timestamp.

In practice, using last_overflow as lower bound is problematic.
If the synflood timestamp is concurrently updated between the time
we read jiffies and the moment we store the timestamp in
'last_overflow', then 'now' becomes smaller than 'last_overflow' and
tcp_synq_no_recent_overflow() returns true, potentially dropping a
valid syncookie.

Reading jiffies after loading the timestamp could fix the problem,
but that'd require a memory barrier. Let's just accommodate for
potential timestamp growth instead and extend the interval using
'last_overflow - HZ' as lower bound.

Signed-off-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-07 13:12:36 +02:00
Guillaume Nault
47fe913c29 tcp: fix rejected syncookies due to stale timestamps
[ Upstream commit 04d26e7b159a396372646a480f4caa166d1b6720 ]

If no synflood happens for a long enough period of time, then the
synflood timestamp isn't refreshed and jiffies can advance so much
that time_after32() can't accurately compare them any more.

Therefore, we can end up in a situation where time_after32(now,
last_overflow + HZ) returns false, just because these two values are
too far apart. In that case, the synflood timestamp isn't updated as
it should be, which can trick tcp_synq_no_recent_overflow() into
rejecting valid syncookies.

For example, let's consider the following scenario on a system
with HZ=1000:

  * The synflood timestamp is 0, either because that's the timestamp
    of the last synflood or, more commonly, because we're working with
    a freshly created socket.

  * We receive a new SYN, which triggers synflood protection. Let's say
    that this happens when jiffies == 2147484649 (that is,
    'synflood timestamp' + HZ + 2^31 + 1).

  * Then tcp_synq_overflow() doesn't update the synflood timestamp,
    because time_after32(2147484649, 1000) returns false.
    With:
      - 2147484649: the value of jiffies, aka. 'now'.
      - 1000: the value of 'last_overflow' + HZ.

  * A bit later, we receive the ACK completing the 3WHS. But
    cookie_v[46]_check() rejects it because tcp_synq_no_recent_overflow()
    says that we're not under synflood. That's because
    time_after32(2147484649, 120000) returns false.
    With:
      - 2147484649: the value of jiffies, aka. 'now'.
      - 120000: the value of 'last_overflow' + TCP_SYNCOOKIE_VALID.

    Of course, in reality jiffies would have increased a bit, but this
    condition will last for the next 119 seconds, which is far enough
    to accommodate for jiffie's growth.

Fix this by updating the overflow timestamp whenever jiffies isn't
within the [last_overflow, last_overflow + HZ] range. That shouldn't
have any performance impact since the update still happens at most once
per second.

Now we're guaranteed to have fresh timestamps while under synflood, so
tcp_synq_no_recent_overflow() can safely use it with time_after32() in
such situations.

Stale timestamps can still make tcp_synq_no_recent_overflow() return
the wrong verdict when not under synflood. This will be handled in the
next patch.

For 64 bits architectures, the problem was introduced with the
conversion of ->tw_ts_recent_stamp to 32 bits integer by commit
cca9bab1b72c ("tcp: use monotonic timestamps for PAWS").
The problem has always been there on 32 bits architectures.

Fixes: cca9bab1b72c ("tcp: use monotonic timestamps for PAWS")
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-07 13:12:34 +02:00
Eric Dumazet
438a890c80 inet: protect against too small mtu values.
[ Upstream commit 501a90c945103e8627406763dac418f20f3837b2 ]

syzbot was once again able to crash a host by setting a very small mtu
on loopback device.

Let's make inetdev_valid_mtu() available in include/net/ip.h,
and use it in ip_setup_cork(), so that we protect both ip_append_page()
and __ip_append_data()

Also add a READ_ONCE() when the device mtu is read.

Pairs this lockless read with one WRITE_ONCE() in __dev_set_mtu(),
even if other code paths might write over this field.

Add a big comment in include/linux/netdevice.h about dev->mtu
needing READ_ONCE()/WRITE_ONCE() annotations.

Hopefully we will add the missing ones in followup patches.

[1]

refcount_t: saturated; leaking memory.
WARNING: CPU: 0 PID: 9464 at lib/refcount.c:22 refcount_warn_saturate+0x138/0x1f0 lib/refcount.c:22
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 9464 Comm: syz-executor850 Not tainted 5.4.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x197/0x210 lib/dump_stack.c:118
 panic+0x2e3/0x75c kernel/panic.c:221
 __warn.cold+0x2f/0x3e kernel/panic.c:582
 report_bug+0x289/0x300 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:174 [inline]
 fixup_bug arch/x86/kernel/traps.c:169 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:267
 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:286
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
RIP: 0010:refcount_warn_saturate+0x138/0x1f0 lib/refcount.c:22
Code: 06 31 ff 89 de e8 c8 f5 e6 fd 84 db 0f 85 6f ff ff ff e8 7b f4 e6 fd 48 c7 c7 e0 71 4f 88 c6 05 56 a6 a4 06 01 e8 c7 a8 b7 fd <0f> 0b e9 50 ff ff ff e8 5c f4 e6 fd 0f b6 1d 3d a6 a4 06 31 ff 89
RSP: 0018:ffff88809689f550 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff815e4336 RDI: ffffed1012d13e9c
RBP: ffff88809689f560 R08: ffff88809c50a3c0 R09: fffffbfff15d31b1
R10: fffffbfff15d31b0 R11: ffffffff8ae98d87 R12: 0000000000000001
R13: 0000000000040100 R14: ffff888099041104 R15: ffff888218d96e40
 refcount_add include/linux/refcount.h:193 [inline]
 skb_set_owner_w+0x2b6/0x410 net/core/sock.c:1999
 sock_wmalloc+0xf1/0x120 net/core/sock.c:2096
 ip_append_page+0x7ef/0x1190 net/ipv4/ip_output.c:1383
 udp_sendpage+0x1c7/0x480 net/ipv4/udp.c:1276
 inet_sendpage+0xdb/0x150 net/ipv4/af_inet.c:821
 kernel_sendpage+0x92/0xf0 net/socket.c:3794
 sock_sendpage+0x8b/0xc0 net/socket.c:936
 pipe_to_sendpage+0x2da/0x3c0 fs/splice.c:458
 splice_from_pipe_feed fs/splice.c:512 [inline]
 __splice_from_pipe+0x3ee/0x7c0 fs/splice.c:636
 splice_from_pipe+0x108/0x170 fs/splice.c:671
 generic_splice_sendpage+0x3c/0x50 fs/splice.c:842
 do_splice_from fs/splice.c:861 [inline]
 direct_splice_actor+0x123/0x190 fs/splice.c:1035
 splice_direct_to_actor+0x3b4/0xa30 fs/splice.c:990
 do_splice_direct+0x1da/0x2a0 fs/splice.c:1078
 do_sendfile+0x597/0xd00 fs/read_write.c:1464
 __do_sys_sendfile64 fs/read_write.c:1525 [inline]
 __se_sys_sendfile64 fs/read_write.c:1511 [inline]
 __x64_sys_sendfile64+0x1dd/0x220 fs/read_write.c:1511
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x441409
Code: e8 ac e8 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fffb64c4f78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441409
RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000005
RBP: 0000000000073b8a R08: 0000000000000010 R09: 0000000000000010
R10: 0000000000010001 R11: 0000000000000246 R12: 0000000000402180
R13: 0000000000402210 R14: 0000000000000000 R15: 0000000000000000
Kernel Offset: disabled
Rebooting in 86400 seconds..

Fixes: 1470ddf7f8ce ("inet: Remove explicit write references to sk/inet in ip_append_data")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-07 13:12:32 +02:00
Eric Dumazet
2a5cbb17f5 net: fix possible overflow in __sk_mem_raise_allocated()
[ Upstream commit 5bf325a53202b8728cf7013b72688c46071e212e ]

With many active TCP sockets, fat TCP sockets could fool
__sk_mem_raise_allocated() thanks to an overflow.

They would increase their share of the memory, instead
of decreasing it.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-07 12:43:02 +02:00
Cong Wang
3024016f72 llc: avoid blocking in llc_sap_close()
[ Upstream commit 9708d2b5b7c648e8e0a40d11e8cea12f6277f33c ]

llc_sap_close() is called by llc_sap_put() which
could be called in BH context in llc_rcv(). We can't
block in BH.

There is no reason to block it here, kfree_rcu() should
be sufficient.

Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-07 12:27:44 +02:00
Eric Dumazet
cf70a97768 net: prevent load/store tearing on sk->sk_stamp
[ Upstream commit f75359f3ac855940c5718af10ba089b8977bf339 ]

Add a couple of READ_ONCE() and WRITE_ONCE() to prevent
load-tearing and store-tearing in sock_read_timestamp()
and sock_write_timestamp()

This might prevent another KCSAN report.

Fixes: 3a0ed3e96197 ("sock: Make sock->sk_stamp thread-safe")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Deepa Dinamani <deepa.kernel@gmail.com>
Acked-by: Deepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-07 11:58:56 +02:00
Eric Dumazet
71b4848540 ipvs: move old_secure_tcp into struct netns_ipvs
[ Upstream commit c24b75e0f9239e78105f81c5f03a751641eb07ef ]

syzbot reported the following issue :

BUG: KCSAN: data-race in update_defense_level / update_defense_level

read to 0xffffffff861a6260 of 4 bytes by task 3006 on cpu 1:
 update_defense_level+0x621/0xb30 net/netfilter/ipvs/ip_vs_ctl.c:177
 defense_work_handler+0x3d/0xd0 net/netfilter/ipvs/ip_vs_ctl.c:225
 process_one_work+0x3d4/0x890 kernel/workqueue.c:2269
 worker_thread+0xa0/0x800 kernel/workqueue.c:2415
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

write to 0xffffffff861a6260 of 4 bytes by task 7333 on cpu 0:
 update_defense_level+0xa62/0xb30 net/netfilter/ipvs/ip_vs_ctl.c:205
 defense_work_handler+0x3d/0xd0 net/netfilter/ipvs/ip_vs_ctl.c:225
 process_one_work+0x3d4/0x890 kernel/workqueue.c:2269
 worker_thread+0xa0/0x800 kernel/workqueue.c:2415
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 7333 Comm: kworker/0:5 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events defense_work_handler

Indeed, old_secure_tcp is currently a static variable, while it
needs to be a per netns variable.

Fixes: a0840e2e165a ("IPVS: netns, ip_vs_ctl local vars moved to ipvs struct.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-07 11:49:17 +02:00
Lukas Wunner
e48da123c6 netfilter: nf_tables: Align nft_expr private data to 64-bit
commit 250367c59e6ba0d79d702a059712d66edacd4a1a upstream.

Invoking the following commands on a 32-bit architecture with strict
alignment requirements (such as an ARMv7-based Raspberry Pi) results
in an alignment exception:

 # nft add table ip test-ip4
 # nft add chain ip test-ip4 output { type filter hook output priority 0; }
 # nft add rule  ip test-ip4 output quota 1025 bytes

Alignment trap: not handling instruction e1b26f9f at [<7f4473f8>]
Unhandled fault: alignment exception (0x001) at 0xb832e824
Internal error: : 1 [#1] PREEMPT SMP ARM
Hardware name: BCM2835
[<7f4473fc>] (nft_quota_do_init [nft_quota])
[<7f447448>] (nft_quota_init [nft_quota])
[<7f4260d0>] (nf_tables_newrule [nf_tables])
[<7f4168dc>] (nfnetlink_rcv_batch [nfnetlink])
[<7f416bd0>] (nfnetlink_rcv [nfnetlink])
[<8078b334>] (netlink_unicast)
[<8078b664>] (netlink_sendmsg)
[<8071b47c>] (sock_sendmsg)
[<8071bd18>] (___sys_sendmsg)
[<8071ce3c>] (__sys_sendmsg)
[<8071ce94>] (sys_sendmsg)

The reason is that nft_quota_do_init() calls atomic64_set() on an
atomic64_t which is only aligned to 32-bit, not 64-bit, because it
succeeds struct nft_expr in memory which only contains a 32-bit pointer.
Fix by aligning the nft_expr private data to 64-bit.

Fixes: 96518518cc41 ("netfilter: add nftables")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: stable@vger.kernel.org # v3.13+
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-07 11:48:50 +02:00
Eric Dumazet
3017dbd446 net: fix data-race in neigh_event_send()
[ Upstream commit 1b53d64435d56902fc234ff2507142d971a09687 ]

KCSAN reported the following data-race [1]

The fix will also prevent the compiler from optimizing out
the condition.

[1]

BUG: KCSAN: data-race in neigh_resolve_output / neigh_resolve_output

write to 0xffff8880a41dba78 of 8 bytes by interrupt on cpu 1:
 neigh_event_send include/net/neighbour.h:443 [inline]
 neigh_resolve_output+0x78/0x480 net/core/neighbour.c:1474
 neigh_output include/net/neighbour.h:511 [inline]
 ip_finish_output2+0x4af/0xe40 net/ipv4/ip_output.c:228
 __ip_finish_output net/ipv4/ip_output.c:308 [inline]
 __ip_finish_output+0x23a/0x490 net/ipv4/ip_output.c:290
 ip_finish_output+0x41/0x160 net/ipv4/ip_output.c:318
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip_output+0xdf/0x210 net/ipv4/ip_output.c:432
 dst_output include/net/dst.h:436 [inline]
 ip_local_out+0x74/0x90 net/ipv4/ip_output.c:125
 __ip_queue_xmit+0x3a8/0xa40 net/ipv4/ip_output.c:532
 ip_queue_xmit+0x45/0x60 include/net/ip.h:237
 __tcp_transmit_skb+0xe81/0x1d60 net/ipv4/tcp_output.c:1169
 tcp_transmit_skb net/ipv4/tcp_output.c:1185 [inline]
 __tcp_retransmit_skb+0x4bd/0x15f0 net/ipv4/tcp_output.c:2976
 tcp_retransmit_skb+0x36/0x1a0 net/ipv4/tcp_output.c:2999
 tcp_retransmit_timer+0x719/0x16d0 net/ipv4/tcp_timer.c:515
 tcp_write_timer_handler+0x42d/0x510 net/ipv4/tcp_timer.c:598
 tcp_write_timer+0xd1/0xf0 net/ipv4/tcp_timer.c:618

read to 0xffff8880a41dba78 of 8 bytes by interrupt on cpu 0:
 neigh_event_send include/net/neighbour.h:442 [inline]
 neigh_resolve_output+0x57/0x480 net/core/neighbour.c:1474
 neigh_output include/net/neighbour.h:511 [inline]
 ip_finish_output2+0x4af/0xe40 net/ipv4/ip_output.c:228
 __ip_finish_output net/ipv4/ip_output.c:308 [inline]
 __ip_finish_output+0x23a/0x490 net/ipv4/ip_output.c:290
 ip_finish_output+0x41/0x160 net/ipv4/ip_output.c:318
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip_output+0xdf/0x210 net/ipv4/ip_output.c:432
 dst_output include/net/dst.h:436 [inline]
 ip_local_out+0x74/0x90 net/ipv4/ip_output.c:125
 __ip_queue_xmit+0x3a8/0xa40 net/ipv4/ip_output.c:532
 ip_queue_xmit+0x45/0x60 include/net/ip.h:237
 __tcp_transmit_skb+0xe81/0x1d60 net/ipv4/tcp_output.c:1169
 tcp_transmit_skb net/ipv4/tcp_output.c:1185 [inline]
 __tcp_retransmit_skb+0x4bd/0x15f0 net/ipv4/tcp_output.c:2976
 tcp_retransmit_skb+0x36/0x1a0 net/ipv4/tcp_output.c:2999
 tcp_retransmit_timer+0x719/0x16d0 net/ipv4/tcp_timer.c:515
 tcp_write_timer_handler+0x42d/0x510 net/ipv4/tcp_timer.c:598

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-07 11:48:14 +02:00
Eric Dumazet
130bef27d8 net/flow_dissector: switch to siphash
commit 55667441c84fa5e0911a0aac44fb059c15ba6da2 upstream.

UDP IPv6 packets auto flowlabels are using a 32bit secret
(static u32 hashrnd in net/core/flow_dissector.c) and
apply jhash() over fields known by the receivers.

Attackers can easily infer the 32bit secret and use this information
to identify a device and/or user, since this 32bit secret is only
set at boot time.

Really, using jhash() to generate cookies sent on the wire
is a serious security concern.

Trying to change the rol32(hash, 16) in ip6_make_flowlabel() would be
a dead end. Trying to periodically change the secret (like in sch_sfq.c)
could change paths taken in the network for long lived flows.

Let's switch to siphash, as we did in commit df453700e8d8
("inet: switch IP ID generator to siphash")

Using a cryptographically strong pseudo random function will solve this
privacy issue and more generally remove other weak points in the stack.

Packet schedulers using skb_get_hash_perturb() benefit from this change.

Fixes: b56774163f99 ("ipv6: Enable auto flow labels by default")
Fixes: 42240901f7c4 ("ipv6: Implement different admin modes for automatic flow labels")
Fixes: 67800f9b1f4e ("ipv6: Call skb_get_hash_flowi6 to get skb->hash in ip6_make_flowlabel")
Fixes: cb1ce2ef387b ("ipv6: Implement automatic flow label generation on transmit")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Jonathan Berger <jonathann1@walla.com>
Reported-by: Amit Klein <aksecurity@gmail.com>
Reported-by: Benny Pinkas <benny@pinkas.net>
Cc: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-07 09:29:43 +02:00
Tejun Heo
8fcb9bb153 net: fix sk_page_frag() recursion from memory reclaim
[ Upstream commit 20eb4f29b60286e0d6dc01d9c260b4bd383c58fb ]

sk_page_frag() optimizes skb_frag allocations by using per-task
skb_frag cache when it knows it's the only user.  The condition is
determined by seeing whether the socket allocation mask allows
blocking - if the allocation may block, it obviously owns the task's
context and ergo exclusively owns current->task_frag.

Unfortunately, this misses recursion through memory reclaim path.
Please take a look at the following backtrace.

 [2] RIP: 0010:tcp_sendmsg_locked+0xccf/0xe10
     ...
     tcp_sendmsg+0x27/0x40
     sock_sendmsg+0x30/0x40
     sock_xmit.isra.24+0xa1/0x170 [nbd]
     nbd_send_cmd+0x1d2/0x690 [nbd]
     nbd_queue_rq+0x1b5/0x3b0 [nbd]
     __blk_mq_try_issue_directly+0x108/0x1b0
     blk_mq_request_issue_directly+0xbd/0xe0
     blk_mq_try_issue_list_directly+0x41/0xb0
     blk_mq_sched_insert_requests+0xa2/0xe0
     blk_mq_flush_plug_list+0x205/0x2a0
     blk_flush_plug_list+0xc3/0xf0
 [1] blk_finish_plug+0x21/0x2e
     _xfs_buf_ioapply+0x313/0x460
     __xfs_buf_submit+0x67/0x220
     xfs_buf_read_map+0x113/0x1a0
     xfs_trans_read_buf_map+0xbf/0x330
     xfs_btree_read_buf_block.constprop.42+0x95/0xd0
     xfs_btree_lookup_get_block+0x95/0x170
     xfs_btree_lookup+0xcc/0x470
     xfs_bmap_del_extent_real+0x254/0x9a0
     __xfs_bunmapi+0x45c/0xab0
     xfs_bunmapi+0x15/0x30
     xfs_itruncate_extents_flags+0xca/0x250
     xfs_free_eofblocks+0x181/0x1e0
     xfs_fs_destroy_inode+0xa8/0x1b0
     destroy_inode+0x38/0x70
     dispose_list+0x35/0x50
     prune_icache_sb+0x52/0x70
     super_cache_scan+0x120/0x1a0
     do_shrink_slab+0x120/0x290
     shrink_slab+0x216/0x2b0
     shrink_node+0x1b6/0x4a0
     do_try_to_free_pages+0xc6/0x370
     try_to_free_mem_cgroup_pages+0xe3/0x1e0
     try_charge+0x29e/0x790
     mem_cgroup_charge_skmem+0x6a/0x100
     __sk_mem_raise_allocated+0x18e/0x390
     __sk_mem_schedule+0x2a/0x40
 [0] tcp_sendmsg_locked+0x8eb/0xe10
     tcp_sendmsg+0x27/0x40
     sock_sendmsg+0x30/0x40
     ___sys_sendmsg+0x26d/0x2b0
     __sys_sendmsg+0x57/0xa0
     do_syscall_64+0x42/0x100
     entry_SYSCALL_64_after_hwframe+0x44/0xa9

In [0], tcp_send_msg_locked() was using current->page_frag when it
called sk_wmem_schedule().  It already calculated how many bytes can
be fit into current->page_frag.  Due to memory pressure,
sk_wmem_schedule() called into memory reclaim path which called into
xfs and then IO issue path.  Because the filesystem in question is
backed by nbd, the control goes back into the tcp layer - back into
tcp_sendmsg_locked().

nbd sets sk_allocation to (GFP_NOIO | __GFP_MEMALLOC) which makes
sense - it's in the process of freeing memory and wants to be able to,
e.g., drop clean pages to make forward progress.  However, this
confused sk_page_frag() called from [2].  Because it only tests
whether the allocation allows blocking which it does, it now thinks
current->page_frag can be used again although it already was being
used in [0].

After [2] used current->page_frag, the offset would be increased by
the used amount.  When the control returns to [0],
current->page_frag's offset is increased and the previously calculated
number of bytes now may overrun the end of allocated memory leading to
silent memory corruptions.

Fix it by adding gfpflags_normal_context() which tests sleepable &&
!reclaim and use it to determine whether to use current->task_frag.

v2: Eric didn't like gfp flags being tested twice.  Introduce a new
    helper gfpflags_normal_context() and combine the two tests.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-07 09:29:17 +02:00
Xin Long
b9810220bc sctp: fix the issue that flags are ignored when using kernel_connect
commit 644fbdeacf1d3edd366e44b8ba214de9d1dd66a9 upstream.

Now sctp uses inet_dgram_connect as its proto_ops .connect, and the flags
param can't be passed into its proto .connect where this flags is really
needed.

sctp works around it by getting flags from socket file in __sctp_connect.
It works for connecting from userspace, as inherently the user sock has
socket file and it passes f_flags as the flags param into the proto_ops
.connect.

However, the sock created by sock_create_kern doesn't have a socket file,
and it passes the flags (like O_NONBLOCK) by using the flags param in
kernel_connect, which calls proto_ops .connect later.

So to fix it, this patch defines a new proto_ops .connect for sctp,
sctp_inet_connect, which calls __sctp_connect() directly with this
flags param. After this, the sctp's proto .connect can be removed.

Note that sctp_inet_connect doesn't need to do some checks that are not
needed for sctp, which makes thing better than with inet_dgram_connect.

Suggested-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Reviewed-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-07 09:28:40 +02:00
Eric Dumazet
2697db574a sch_netem: fix rcu splat in netem_enqueue()
commit 159d2c7d8106177bd9a986fd005a311fe0d11285 upstream.

qdisc_root() use from netem_enqueue() triggers a lockdep warning.

__dev_queue_xmit() uses rcu_read_lock_bh() which is
not equivalent to rcu_read_lock() + local_bh_disable_bh as far
as lockdep is concerned.

WARNING: suspicious RCU usage
5.3.0-rc7+ #0 Not tainted
-----------------------------
include/net/sch_generic.h:492 suspicious rcu_dereference_check() usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
3 locks held by syz-executor427/8855:
 #0: 00000000b5525c01 (rcu_read_lock_bh){....}, at: lwtunnel_xmit_redirect include/net/lwtunnel.h:92 [inline]
 #0: 00000000b5525c01 (rcu_read_lock_bh){....}, at: ip_finish_output2+0x2dc/0x2570 net/ipv4/ip_output.c:214
 #1: 00000000b5525c01 (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x20a/0x3650 net/core/dev.c:3804
 #2: 00000000364bae92 (&(&sch->q.lock)->rlock){+.-.}, at: spin_lock include/linux/spinlock.h:338 [inline]
 #2: 00000000364bae92 (&(&sch->q.lock)->rlock){+.-.}, at: __dev_xmit_skb net/core/dev.c:3502 [inline]
 #2: 00000000364bae92 (&(&sch->q.lock)->rlock){+.-.}, at: __dev_queue_xmit+0x14b8/0x3650 net/core/dev.c:3838

stack backtrace:
CPU: 0 PID: 8855 Comm: syz-executor427 Not tainted 5.3.0-rc7+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 lockdep_rcu_suspicious+0x153/0x15d kernel/locking/lockdep.c:5357
 qdisc_root include/net/sch_generic.h:492 [inline]
 netem_enqueue+0x1cfb/0x2d80 net/sched/sch_netem.c:479
 __dev_xmit_skb net/core/dev.c:3527 [inline]
 __dev_queue_xmit+0x15d2/0x3650 net/core/dev.c:3838
 dev_queue_xmit+0x18/0x20 net/core/dev.c:3902
 neigh_hh_output include/net/neighbour.h:500 [inline]
 neigh_output include/net/neighbour.h:509 [inline]
 ip_finish_output2+0x1726/0x2570 net/ipv4/ip_output.c:228
 __ip_finish_output net/ipv4/ip_output.c:308 [inline]
 __ip_finish_output+0x5fc/0xb90 net/ipv4/ip_output.c:290
 ip_finish_output+0x38/0x1f0 net/ipv4/ip_output.c:318
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip_mc_output+0x292/0xf40 net/ipv4/ip_output.c:417
 dst_output include/net/dst.h:436 [inline]
 ip_local_out+0xbb/0x190 net/ipv4/ip_output.c:125
 ip_send_skb+0x42/0xf0 net/ipv4/ip_output.c:1555
 udp_send_skb.isra.0+0x6b2/0x1160 net/ipv4/udp.c:887
 udp_sendmsg+0x1e96/0x2820 net/ipv4/udp.c:1174
 inet_sendmsg+0x9e/0xe0 net/ipv4/af_inet.c:807
 sock_sendmsg_nosec net/socket.c:637 [inline]
 sock_sendmsg+0xd7/0x130 net/socket.c:657
 ___sys_sendmsg+0x3e2/0x920 net/socket.c:2311
 __sys_sendmmsg+0x1bf/0x4d0 net/socket.c:2413
 __do_sys_sendmmsg net/socket.c:2442 [inline]
 __se_sys_sendmmsg net/socket.c:2439 [inline]
 __x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2439
 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-07 09:28:38 +02:00
Eric Biggers
fc806cc479 llc: fix sk_buff leak in llc_conn_service()
commit b74555de21acd791f12c4a1aeaf653dd7ac21133 upstream.

syzbot reported:

    BUG: memory leak
    unreferenced object 0xffff88811eb3de00 (size 224):
       comm "syz-executor559", pid 7315, jiffies 4294943019 (age 10.300s)
       hex dump (first 32 bytes):
         00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
         00 a0 38 24 81 88 ff ff 00 c0 f2 15 81 88 ff ff  ..8$............
       backtrace:
         [<000000008d1c66a1>] kmemleak_alloc_recursive  include/linux/kmemleak.h:55 [inline]
         [<000000008d1c66a1>] slab_post_alloc_hook mm/slab.h:439 [inline]
         [<000000008d1c66a1>] slab_alloc_node mm/slab.c:3269 [inline]
         [<000000008d1c66a1>] kmem_cache_alloc_node+0x153/0x2a0 mm/slab.c:3579
         [<00000000447d9496>] __alloc_skb+0x6e/0x210 net/core/skbuff.c:198
         [<000000000cdbf82f>] alloc_skb include/linux/skbuff.h:1058 [inline]
         [<000000000cdbf82f>] llc_alloc_frame+0x66/0x110 net/llc/llc_sap.c:54
         [<000000002418b52e>] llc_conn_ac_send_sabme_cmd_p_set_x+0x2f/0x140  net/llc/llc_c_ac.c:777
         [<000000001372ae17>] llc_exec_conn_trans_actions net/llc/llc_conn.c:475  [inline]
         [<000000001372ae17>] llc_conn_service net/llc/llc_conn.c:400 [inline]
         [<000000001372ae17>] llc_conn_state_process+0x1ac/0x640  net/llc/llc_conn.c:75
         [<00000000f27e53c1>] llc_establish_connection+0x110/0x170  net/llc/llc_if.c:109
         [<00000000291b2ca0>] llc_ui_connect+0x10e/0x370 net/llc/af_llc.c:477
         [<000000000f9c740b>] __sys_connect+0x11d/0x170 net/socket.c:1840
         [...]

The bug is that most callers of llc_conn_send_pdu() assume it consumes a
reference to the skb, when actually due to commit b85ab56c3f81 ("llc:
properly handle dev_queue_xmit() return value") it doesn't.

Revert most of that commit, and instead make the few places that need
llc_conn_send_pdu() to *not* consume a reference call skb_get() before.

Fixes: b85ab56c3f81 ("llc: properly handle dev_queue_xmit() return value")
Reported-by: syzbot+6b825a6494a04cc0e3f7@syzkaller.appspotmail.com
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-07 09:28:32 +02:00
Cong Wang
91a7143ffc xfrm: clean up xfrm protocol checks
commit dbb2483b2a46fbaf833cfb5deb5ed9cace9c7399 upstream.

In commit 6a53b7593233 ("xfrm: check id proto in validate_tmpl()")
I introduced a check for xfrm protocol, but according to Herbert
IPSEC_PROTO_ANY should only be used as a wildcard for lookup, so
it should be removed from validate_tmpl().

And, IPSEC_PROTO_ANY is expected to only match 3 IPSec-specific
protocols, this is why xfrm_state_flush() could still miss
IPPROTO_ROUTING, which leads that those entries are left in
net->xfrm.state_all before exit net. Fix this by replacing
IPSEC_PROTO_ANY with zero.

This patch also extracts the check from validate_tmpl() to
xfrm_id_proto_valid() and uses it in parse_ipsecrequest().
With this, no other protocols should be added into xfrm.

Fixes: 6a53b7593233 ("xfrm: check id proto in validate_tmpl()")
Reported-by: syzbot+0bf0519d6e0de15914fe@syzkaller.appspotmail.com
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Zubin Mithra <zsm@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-06 21:34:53 +02:00
Tim Froidcoeur
abf459a4ac tcp: fix tcp_rtx_queue_tail in case of empty retransmit queue
Commit 8c3088f895a0 ("tcp: be more careful in tcp_fragment()")
triggers following stack trace:

[25244.848046] kernel BUG at ./include/linux/skbuff.h:1406!
[25244.859335] RIP: 0010:skb_queue_prev+0x9/0xc
[25244.888167] Call Trace:
[25244.889182]  <IRQ>
[25244.890001]  tcp_fragment+0x9c/0x2cf
[25244.891295]  tcp_write_xmit+0x68f/0x988
[25244.892732]  __tcp_push_pending_frames+0x3b/0xa0
[25244.894347]  tcp_data_snd_check+0x2a/0xc8
[25244.895775]  tcp_rcv_established+0x2a8/0x30d
[25244.897282]  tcp_v4_do_rcv+0xb2/0x158
[25244.898666]  tcp_v4_rcv+0x692/0x956
[25244.899959]  ip_local_deliver_finish+0xeb/0x169
[25244.901547]  __netif_receive_skb_core+0x51c/0x582
[25244.903193]  ? inet_gro_receive+0x239/0x247
[25244.904756]  netif_receive_skb_internal+0xab/0xc6
[25244.906395]  napi_gro_receive+0x8a/0xc0
[25244.907760]  receive_buf+0x9a1/0x9cd
[25244.909160]  ? load_balance+0x17a/0x7b7
[25244.910536]  ? vring_unmap_one+0x18/0x61
[25244.911932]  ? detach_buf+0x60/0xfa
[25244.913234]  virtnet_poll+0x128/0x1e1
[25244.914607]  net_rx_action+0x12a/0x2b1
[25244.915953]  __do_softirq+0x11c/0x26b
[25244.917269]  ? handle_irq_event+0x44/0x56
[25244.918695]  irq_exit+0x61/0xa0
[25244.919947]  do_IRQ+0x9d/0xbb
[25244.921065]  common_interrupt+0x85/0x85
[25244.922479]  </IRQ>

tcp_rtx_queue_tail() (called by tcp_fragment()) can call
tcp_write_queue_prev() on the first packet in the queue, which will trigger
the BUG in tcp_write_queue_prev(), because there is no previous packet.

This happens when the retransmit queue is empty, for example in case of a
zero window.

Commit 8c3088f895a0 ("tcp: be more careful in tcp_fragment()") was not a
simple cherry-pick of the original one from master (b617158dc096)
because there is a specific TCP rtx queue only since v4.15. For more
details, please see the commit message of b617158dc096 ("tcp: be more
careful in tcp_fragment()").

The BUG() is hit due to the specific code added to versions older than
v4.15. The comment in skb_queue_prev() (include/linux/skbuff.h:1406),
just before the BUG_ON() somehow suggests to add a check before using
it, what Tim did.

In master, this code path causing the issue will not be taken because
the implementation of tcp_rtx_queue_tail() is different:

    tcp_fragment() → tcp_rtx_queue_tail() → tcp_write_queue_prev() →
skb_queue_prev() → BUG_ON()

Fixes: 8c3088f895a0 ("tcp: be more careful in tcp_fragment()")
Signed-off-by: Tim Froidcoeur <tim.froidcoeur@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Reviewed-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-06 21:33:16 +02:00
Florian Westphal
811d98164c netfilter: ctnetlink: don't use conntrack/expect object addresses as id
commit 3c79107631db1f7fd32cf3f7368e4672004a3010 upstream.

else, we leak the addresses to userspace via ctnetlink events
and dumps.

Compute an ID on demand based on the immutable parts of nf_conn struct.

Another advantage compared to using an address is that there is no
immediate re-use of the same ID in case the conntrack entry is freed and
reallocated again immediately.

Fixes: 3583240249ef ("[NETFILTER]: nf_conntrack_expect: kill unique ID")
Fixes: 7f85f914721f ("[NETFILTER]: nf_conntrack: kill unique ID")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
[bwh: Backported to 4.4: adjust context]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-06 21:32:47 +02:00
Eric Dumazet
a2ce901263 inet: switch IP ID generator to siphash
commit df453700e8d81b1bdafdf684365ee2b9431fb702 upstream.

According to Amit Klein and Benny Pinkas, IP ID generation is too weak
and might be used by attackers.

Even with recent net_hash_mix() fix (netns: provide pure entropy for net_hash_mix())
having 64bit key and Jenkins hash is risky.

It is time to switch to siphash and its 128bit keys.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Amit Klein <aksecurity@gmail.com>
Reported-by: Benny Pinkas <benny@pinkas.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 4.4: adjust context]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-06 21:32:45 +02:00
Eric Dumazet
84d29690bf tcp: be more careful in tcp_fragment()
[ Upstream commit b617158dc096709d8600c53b6052144d12b89fab ]

Some applications set tiny SO_SNDBUF values and expect
TCP to just work. Recent patches to address CVE-2019-11478
broke them in case of losses, since retransmits might
be prevented.

We should allow these flows to make progress.

This patch allows the first and last skb in retransmit queue
to be split even if memory limits are hit.

It also adds the some room due to the fact that tcp_sendmsg()
and tcp_sendpage() might overshoot sk_wmem_queued by about one full
TSO skb (64KB size). Note this allowance was already present
in stable backports for kernels < 4.15

Note for < 4.15 backports :
 tcp_rtx_queue_tail() will probably look like :

static inline struct sk_buff *tcp_rtx_queue_tail(const struct sock *sk)
{
	struct sk_buff *skb = tcp_send_head(sk);

	return skb ? tcp_write_queue_prev(sk, skb) : tcp_write_queue_tail(sk);
}

Fixes: f070ef2ac667 ("tcp: tcp_fragment() should apply sane memory limits")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Andrew Prout <aprout@ll.mit.edu>
Tested-by: Andrew Prout <aprout@ll.mit.edu>
Tested-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Tested-by: Michal Kubecek <mkubecek@suse.cz>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Christoph Paasch <cpaasch@apple.com>
Cc: Jonathan Looney <jtl@netflix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-06 20:28:05 +02:00
Soheil Hassas Yeganeh
a6ac9983f2 tcp: reset sk_send_head in tcp_write_queue_purge
[ Upstream commit dbbf2d1e4077bab0c65ece2765d3fc69cf7d610f ]

tcp_write_queue_purge clears all the SKBs in the write queue
but does not reset the sk_send_head. As a result, we can have
a NULL pointer dereference anywhere that we use tcp_send_head
instead of the tcp_write_queue_tail.

For example, after a27fd7a8ed38 (tcp: purge write queue upon RST),
we can purge the write queue on RST. Prior to
75c119afe14f (tcp: implement rb-tree based retransmit queue),
tcp_push will only check tcp_send_head and then accesses
tcp_write_queue_tail to send the actual SKB. As a result, it will
dereference a NULL pointer.

This has been reported twice for 4.14 where we don't have
75c119afe14f:

By Timofey Titovets:

[  422.081094] BUG: unable to handle kernel NULL pointer dereference
at 0000000000000038
[  422.081254] IP: tcp_push+0x42/0x110
[  422.081314] PGD 0 P4D 0
[  422.081364] Oops: 0002 [#1] SMP PTI

By Yongjian Xu:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000038
IP: tcp_push+0x48/0x120
PGD 80000007ff77b067 P4D 80000007ff77b067 PUD 7fd989067 PMD 0
Oops: 0002 [#18] SMP PTI
Modules linked in: tcp_diag inet_diag tcp_bbr sch_fq iTCO_wdt
iTCO_vendor_support pcspkr ixgbe mdio i2c_i801 lpc_ich joydev input_leds shpchp
e1000e igb dca ptp pps_core hwmon mei_me mei ipmi_si ipmi_msghandler sg ses
scsi_transport_sas enclosure ext4 jbd2 mbcache sd_mod ahci libahci megaraid_sas
wmi ast ttm dm_mirror dm_region_hash dm_log dm_mod dax
CPU: 6 PID: 14156 Comm: [ET_NET 6] Tainted: G D 4.14.26-1.el6.x86_64 #1
Hardware name: LENOVO ThinkServer RD440 /ThinkServer RD440, BIOS A0TS80A
09/22/2014
task: ffff8807d78d8140 task.stack: ffffc9000e944000
RIP: 0010:tcp_push+0x48/0x120
RSP: 0018:ffffc9000e947a88 EFLAGS: 00010246
RAX: 00000000000005b4 RBX: ffff880f7cce9c00 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000040 RDI: ffff8807d00f5000
RBP: ffffc9000e947aa8 R08: 0000000000001c84 R09: 0000000000000000
R10: ffff8807d00f5158 R11: 0000000000000000 R12: ffff8807d00f5000
R13: 0000000000000020 R14: 00000000000256d4 R15: 0000000000000000
FS: 00007f5916de9700(0000) GS:ffff88107fd00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000038 CR3: 00000007f8226004 CR4: 00000000001606e0
Call Trace:
tcp_sendmsg_locked+0x33d/0xe50
tcp_sendmsg+0x37/0x60
inet_sendmsg+0x39/0xc0
sock_sendmsg+0x49/0x60
sock_write_iter+0xb6/0x100
do_iter_readv_writev+0xec/0x130
? rw_verify_area+0x49/0xb0
do_iter_write+0x97/0xd0
vfs_writev+0x7e/0xe0
? __wake_up_common_lock+0x80/0xa0
? __fget_light+0x2c/0x70
? __do_page_fault+0x1e7/0x530
do_writev+0x60/0xf0
? inet_shutdown+0xac/0x110
SyS_writev+0x10/0x20
do_syscall_64+0x6f/0x140
? prepare_exit_to_usermode+0x8b/0xa0
entry_SYSCALL_64_after_hwframe+0x3d/0xa2
RIP: 0033:0x3135ce0c57
RSP: 002b:00007f5916de4b00 EFLAGS: 00000293 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000003135ce0c57
RDX: 0000000000000002 RSI: 00007f5916de4b90 RDI: 000000000000606f
RBP: 0000000000000000 R08: 0000000000000000 R09: 00007f5916de8c38
R10: 0000000000000000 R11: 0000000000000293 R12: 00000000000464cc
R13: 00007f5916de8c30 R14: 00007f58d8bef080 R15: 0000000000000002
Code: 48 8b 97 60 01 00 00 4c 8d 97 58 01 00 00 41 b9 00 00 00 00 41 89 f3 4c 39
d2 49 0f 44 d1 41 81 e3 00 80 00 00 0f 85 b0 00 00 00 <80> 4a 38 08 44 8b 8f 74
06 00 00 44 89 8f 7c 06 00 00 83 e6 01
RIP: tcp_push+0x48/0x120 RSP: ffffc9000e947a88
CR2: 0000000000000038
---[ end trace 8d545c2e93515549 ]---

There is other scenario which found in stable 4.4:
Allocated:
 [<ffffffff82f380a6>] __alloc_skb+0xe6/0x600 net/core/skbuff.c:218
 [<ffffffff832466c3>] alloc_skb_fclone include/linux/skbuff.h:856 [inline]
 [<ffffffff832466c3>] sk_stream_alloc_skb+0xa3/0x5d0 net/ipv4/tcp.c:833
 [<ffffffff83249164>] tcp_sendmsg+0xd34/0x2b00 net/ipv4/tcp.c:1178
 [<ffffffff83300ef3>] inet_sendmsg+0x203/0x4d0 net/ipv4/af_inet.c:755
Freed:
 [<ffffffff82f372fd>] __kfree_skb+0x1d/0x20 net/core/skbuff.c:676
 [<ffffffff83288834>] sk_wmem_free_skb include/net/sock.h:1447 [inline]
 [<ffffffff83288834>] tcp_write_queue_purge include/net/tcp.h:1460 [inline]
 [<ffffffff83288834>] tcp_connect_init net/ipv4/tcp_output.c:3122 [inline]
 [<ffffffff83288834>] tcp_connect+0xb24/0x30c0 net/ipv4/tcp_output.c:3261
 [<ffffffff8329b991>] tcp_v4_connect+0xf31/0x1890 net/ipv4/tcp_ipv4.c:246

BUG: KASAN: use-after-free in tcp_skb_pcount include/net/tcp.h:796 [inline]
BUG: KASAN: use-after-free in tcp_init_tso_segs net/ipv4/tcp_output.c:1619 [inline]
BUG: KASAN: use-after-free in tcp_write_xmit+0x3fc2/0x4cb0 net/ipv4/tcp_output.c:2056
 [<ffffffff81515cd5>] kasan_report.cold.7+0x175/0x2f7 mm/kasan/report.c:408
 [<ffffffff814f9784>] __asan_report_load2_noabort+0x14/0x20 mm/kasan/report.c:427
 [<ffffffff83286582>] tcp_skb_pcount include/net/tcp.h:796 [inline]
 [<ffffffff83286582>] tcp_init_tso_segs net/ipv4/tcp_output.c:1619 [inline]
 [<ffffffff83286582>] tcp_write_xmit+0x3fc2/0x4cb0 net/ipv4/tcp_output.c:2056
 [<ffffffff83287a40>] __tcp_push_pending_frames+0xa0/0x290 net/ipv4/tcp_output.c:2307

stable 4.4 and stable 4.9 don't have the commit abb4a8b870b5 ("tcp: purge write queue upon RST")
which is referred in dbbf2d1e4077,
in tcp_connect_init, it calls tcp_write_queue_purge, and does not reset sk_send_head, then UAF.

stable 4.14 have the commit abb4a8b870b5 ("tcp: purge write queue upon RST"),
in tcp_reset, it calls tcp_write_queue_purge(sk), and does not reset sk_send_head, then UAF.

So this patch can be used to fix stable 4.4 and 4.9.

Fixes: a27fd7a8ed38 (tcp: purge write queue upon RST)
Reported-by: Timofey Titovets <nefelim4ag@gmail.com>
Reported-by: Yongjian Xu <yongjianchn@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Tested-by: Yongjian Xu <yongjianchn@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Mao Wenan <maowenan@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-06 20:26:04 +02:00
Josh Elsasser
3fb453b42f net: check before dereferencing netdev_ops during busy poll
init_dummy_netdev() leaves its netdev_ops pointer zeroed. This leads
to a NULL pointer dereference when sk_busy_loop fires against an iwlwifi
wireless adapter and checks napi->dev->netdev_ops->ndo_busy_poll.

Avoid this by ensuring napi->dev->netdev_ops is valid before following
the pointer, avoiding the following panic when busy polling on a dummy
netdev:

  BUG: unable to handle kernel NULL pointer dereference at 00000000000000c8
  IP: [<ffffffff817b4b72>] sk_busy_loop+0x92/0x2f0
  Call Trace:
   [<ffffffff815a3134>] ? uart_write_room+0x74/0xf0
   [<ffffffff817964a9>] sock_poll+0x99/0xa0
   [<ffffffff81223142>] do_sys_poll+0x2e2/0x520
   [<ffffffff8118d3fc>] ? get_page_from_freelist+0x3bc/0xa30
   [<ffffffff810ada22>] ? update_curr+0x62/0x140
   [<ffffffff811ea671>] ? __slab_free+0xa1/0x2a0
   [<ffffffff811ea671>] ? __slab_free+0xa1/0x2a0
   [<ffffffff8179dbb1>] ? skb_free_head+0x21/0x30
   [<ffffffff81221bd0>] ? poll_initwait+0x50/0x50
   [<ffffffff811eaa36>] ? kmem_cache_free+0x1c6/0x1e0
   [<ffffffff815a4884>] ? uart_write+0x124/0x1d0
   [<ffffffff810bd1cd>] ? remove_wait_queue+0x4d/0x60
   [<ffffffff810bd224>] ? __wake_up+0x44/0x50
   [<ffffffff81582731>] ? tty_write_unlock+0x31/0x40
   [<ffffffff8158c5c6>] ? tty_ldisc_deref+0x16/0x20
   [<ffffffff81584820>] ? tty_write+0x1e0/0x2f0
   [<ffffffff81587e50>] ? process_echoes+0x80/0x80
   [<ffffffff8120c17b>] ? __vfs_write+0x2b/0x130
   [<ffffffff8120d09a>] ? vfs_write+0x15a/0x1a0
   [<ffffffff81223455>] SyS_poll+0x75/0x100
   [<ffffffff819a6524>] entry_SYSCALL_64_fastpath+0x24/0xcf

Commit 79e7fff47b7b ("net: remove support for per driver ndo_busy_poll()")
indirectly fixed this upstream in linux-4.11 by removing the offending
pointer usage. No other users of napi->dev touch its netdev_ops.

Fixes: 8b80cda536ea ("net: rename include/net/ll_poll.h to include/net/busy_poll.h") # 4.4.y
Signed-off-by: Josh Elsasser <jelsasser@appneta.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-06 19:17:35 +02:00
Marcel Holtmann
bf7688aca6 Bluetooth: Align minimum encryption key size for LE and BR/EDR connections
commit d5bb334a8e171b262e48f378bd2096c0ea458265 upstream.

The minimum encryption key size for LE connections is 56 bits and to
align LE with BR/EDR, enforce 56 bits of minimum encryption key size for
BR/EDR connections as well.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-06 19:16:52 +02:00
Greg Kroah-Hartman
61232d87e8 Revert "Bluetooth: Align minimum encryption key size for LE and BR/EDR connections"
This reverts commit d016dc1bd29a2cfb0707fc6fb290ccd21f3b139c which is
commit d5bb334a8e171b262e48f378bd2096c0ea458265 upstream.

Lots of people have reported issues with this patch, and as there does
not seem to be a fix going into Linus's kernel tree any time soon,
revert the commit in the stable trees so as to get people's machines
working properly again.

Reported-by: Vasily Khoruzhick <anarsoul@gmail.com>
Reported-by: Hans de Goede <hdegoede@redhat.com>
Cc: Jeremy Cline <jeremy@jcline.org>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-06 19:02:48 +02:00
Eric Dumazet
ebca158375 tcp: add tcp_min_snd_mss sysctl
commit 5f3e2bf008c2221478101ee72f5cb4654b9fc363 upstream.

Some TCP peers announce a very small MSS option in their SYN and/or
SYN/ACK messages.

This forces the stack to send packets with a very high network/cpu
overhead.

Linux has enforced a minimal value of 48. Since this value includes
the size of TCP options, and that the options can consume up to 40
bytes, this means that each segment can include only 8 bytes of payload.

In some cases, it can be useful to increase the minimal value
to a saner value.

We still let the default to 48 (TCP_MIN_SND_MSS), for compatibility
reasons.

Note that TCP_MAXSEG socket option enforces a minimal value
of (TCP_MIN_MSS). David Miller increased this minimal value
in commit c39508d6f118 ("tcp: Make TCP_MAXSEG minimum more correct.")
from 64 to 88.

We might in the future merge TCP_MIN_SND_MSS and TCP_MIN_MSS.

CVE-2019-11479 -- tcp mss hardcoded to 48

Signed-off-by: Eric Dumazet <edumazet@google.com>
Suggested-by: Jonathan Looney <jtl@netflix.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Tyler Hicks <tyhicks@canonical.com>
Cc: Bruce Curtis <brucec@netflix.com>
Cc: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-06 18:57:31 +02:00
Eric Dumazet
e6f295792c tcp: limit payload size of sacked skbs
commit 3b4929f65b0d8249f19a50245cd88ed1a2f78cff upstream.

Jonathan Looney reported that TCP can trigger the following crash
in tcp_shifted_skb() :

	BUG_ON(tcp_skb_pcount(skb) < pcount);

This can happen if the remote peer has advertized the smallest
MSS that linux TCP accepts : 48

An skb can hold 17 fragments, and each fragment can hold 32KB
on x86, or 64KB on PowerPC.

This means that the 16bit witdh of TCP_SKB_CB(skb)->tcp_gso_segs
can overflow.

Note that tcp_sendmsg() builds skbs with less than 64KB
of payload, so this problem needs SACK to be enabled.
SACK blocks allow TCP to coalesce multiple skbs in the retransmit
queue, thus filling the 17 fragments to maximal capacity.

CVE-2019-11477 -- u16 overflow of TCP_SKB_CB(skb)->tcp_gso_segs

Backport notes, provided by Joao Martins <joao.m.martins@oracle.com>

v4.15 or since commit 737ff314563 ("tcp: use sequence distance to
detect reordering") had switched from the packet-based FACK tracking and
switched to sequence-based.

v4.14 and older still have the old logic and hence on
tcp_skb_shift_data() needs to retain its original logic and have
@fack_count in sync. In other words, we keep the increment of pcount with
tcp_skb_pcount(skb) to later used that to update fack_count. To make it
more explicit we track the new skb that gets incremented to pcount in
@next_pcount, and we get to avoid the constant invocation of
tcp_skb_pcount(skb) all together.

Fixes: 832d11c5cd07 ("tcp: Try to restore large SKBs while SACK processing")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Jonathan Looney <jtl@netflix.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Tyler Hicks <tyhicks@canonical.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Bruce Curtis <brucec@netflix.com>
Cc: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-06 18:53:40 +02:00
David Ahern
838f228ee1 ipv4: Define __ipv4_neigh_lookup_noref when CONFIG_INET is disabled
commit 9b3040a6aafd7898ece7fc7efcbca71e42aa8069 upstream.

Define __ipv4_neigh_lookup_noref to return NULL when CONFIG_INET is disabled.

Fixes: 4b2a2bfeb3f0 ("neighbor: Call __ipv4_neigh_lookup_noref in neigh_xmit")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-06 18:47:58 +02:00
WANG Cong
1f0443050d ipv6: fix a potential deadlock in do_ipv6_setsockopt()
commit 8651be8f14a12d24f203f283601d9b0418c389ff upstream.

Baozeng reported this deadlock case:

       CPU0                    CPU1
       ----                    ----
  lock([  165.136033] sk_lock-AF_INET6);
                               lock([  165.136033] rtnl_mutex);
                               lock([  165.136033] sk_lock-AF_INET6);
  lock([  165.136033] rtnl_mutex);

Similar to commit 87e9f0315952
("ipv4: fix a potential deadlock in mcast getsockopt() path")
this is due to we still have a case, ipv6_sock_mc_close(),
where we acquire sk_lock before rtnl_lock. Close this deadlock
with the similar solution, that is always acquire rtnl lock first.

Fixes: baf606d9c9b1 ("ipv4,ipv6: grab rtnl before locking the socket")
Reported-by: Baozeng Ding <sploving1@gmail.com>
Tested-by: Baozeng Ding <sploving1@gmail.com>
Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Zubin Mithra <zsm@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-06 16:43:14 +02:00
Marcel Holtmann
9ac1c34ea1 Bluetooth: Align minimum encryption key size for LE and BR/EDR connections
commit d5bb334a8e171b262e48f378bd2096c0ea458265 upstream.

The minimum encryption key size for LE connections is 56 bits and to
align LE with BR/EDR, enforce 56 bits of minimum encryption key size for
BR/EDR connections as well.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-06 16:43:10 +02:00
Eric Dumazet
cafcefee69 netns: provide pure entropy for net_hash_mix()
[ Upstream commit 355b98553789b646ed97ad801a619ff898471b92 ]

net_hash_mix() currently uses kernel address of a struct net,
and is used in many places that could be used to reveal this
address to a patient attacker, thus defeating KASLR, for
the typical case (initial net namespace, &init_net is
not dynamically allocated)

I believe the original implementation tried to avoid spending
too many cycles in this function, but security comes first.

Also provide entropy regardless of CONFIG_NET_NS.

Fixes: 0b4419162aa6 ("netns: introduce the net_hash_mix "salt" for hashes")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Amit Klein <aksecurity@gmail.com>
Reported-by: Benny Pinkas <benny@pinkas.net>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-06 15:08:06 +02:00
Florian Westphal
35a11a4675 netfilter: physdev: relax br_netfilter dependency
[ Upstream commit 8e2f311a68494a6677c1724bdcb10bada21af37c ]

Following command:
  iptables -D FORWARD -m physdev ...
causes connectivity loss in some setups.

Reason is that iptables userspace will probe kernel for the module revision
of the physdev patch, and physdev has an artificial dependency on
br_netfilter (xt_physdev use makes no sense unless a br_netfilter module
is loaded).

This causes the "phydev" module to be loaded, which in turn enables the
"call-iptables" infrastructure.

bridged packets might then get dropped by the iptables ruleset.

The better fix would be to change the "call-iptables" defaults to 0 and
enforce explicit setting to 1, but that breaks backwards compatibility.

This does the next best thing: add a request_module call to checkentry.
This was a stray '-D ... -m physdev' won't activate br_netfilter
anymore.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-06 14:52:27 +02:00
Xin Long
9bffda7ca8 sctp: get sctphdr by offset in sctp_compute_cksum
[ Upstream commit 273160ffc6b993c7c91627f5a84799c66dfe4dee ]

sctp_hdr(skb) only works when skb->transport_header is set properly.

But in Netfilter, skb->transport_header for ipv6 is not guaranteed
to be right value for sctphdr. It would cause to fail to check the
checksum for sctp packets.

So fix it by using offset, which is always right in all places.

v1->v2:
  - Fix the changelog.

Fixes: e6d8b64b34aa ("net: sctp: fix and consolidate SCTP checksumming code")
Reported-by: Li Shuang <shuali@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-06 12:57:16 +02:00
Maxime Chevallier
9015a061d2 packets: Always register packet sk in the same order
[ Upstream commit a4dc6a49156b1f8d6e17251ffda17c9e6a5db78a ]

When using fanouts with AF_PACKET, the demux functions such as
fanout_demux_cpu will return an index in the fanout socket array, which
corresponds to the selected socket.

The ordering of this array depends on the order the sockets were added
to a given fanout group, so for FANOUT_CPU this means sockets are bound
to cpus in the order they are configured, which is OK.

However, when stopping then restarting the interface these sockets are
bound to, the sockets are reassigned to the fanout group in the reverse
order, due to the fact that they were inserted at the head of the
interface's AF_PACKET socket list.

This means that traffic that was directed to the first socket in the
fanout group is now directed to the last one after an interface restart.

In the case of FANOUT_CPU, traffic from CPU0 will be directed to the
socket that used to receive traffic from the last CPU after an interface
restart.

This commit introduces a helper to add a socket at the tail of a list,
then uses it to register AF_PACKET sockets.

Note that this changes the order in which sockets are listed in /proc and
with sock_diag.

Fixes: dc99f600698d ("packet: Add fanout support")
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-06 12:57:10 +02:00
Eric Dumazet
b23b35eb39 tcp/dccp: drop SYN packets if accept queue is full
commit 5ea8ea2cb7f1d0db15762c9b0bb9e7330425a071 upstream.

Per listen(fd, backlog) rules, there is really no point accepting a SYN,
sending a SYNACK, and dropping the following ACK packet if accept queue
is full, because application is not draining accept queue fast enough.

This behavior is fooling TCP clients that believe they established a
flow, while there is nothing at server side. They might then send about
10 MSS (if using IW10) that will be dropped anyway while server is under
stress.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-06 11:16:42 +02:00
prashantpaddune
3bca37f224 A750FXXU4CTBC 2020-03-27 21:51:54 +05:30