linux-stable.git/net/core, branch v4.14.166

ethtool: reduce stack usage with clang

2020-01-17T18:45:40+00:00

commit 3499e87ea0413ee5b2cc028f4c8ed4d424bc7f98 upstream.

clang inlines the dev_ethtool() more aggressively than gcc does, leading
to a larger amount of used stack space:

net/core/ethtool.c:2536:24: error: stack frame size of 1216 bytes in function 'dev_ethtool' [-Werror,-Wframe-larger-than=]

Marking the sub-functions that require the most stack space as
noinline_for_stack gives us reasonable behavior on all compilers.

Signed-off-by: Arnd Bergmann 
Reviewed-by: Michal Kubecek 
Signed-off-by: David S. Miller 
Signed-off-by: Miles Chen 
Signed-off-by: Greg Kroah-Hartman

net: add annotations on hh->hh_len lockless accesses

2020-01-09T09:17:59+00:00

[ 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 
Reported-by: syzbot 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net, sysctl: Fix compiler warning when only cBPF is present

2020-01-04T12:59:59+00:00

[ Upstream commit 1148f9adbe71415836a18a36c1b4ece999ab0973 ]

proc_dointvec_minmax_bpf_restricted() has been firstly introduced
in commit 2e4a30983b0f ("bpf: restrict access to core bpf sysctls")
under CONFIG_HAVE_EBPF_JIT. Then, this ifdef has been removed in
ede95a63b5e8 ("bpf: add bpf_jit_limit knob to restrict unpriv
allocations"), because a new sysctl, bpf_jit_limit, made use of it.
Finally, this parameter has become long instead of integer with
fdadd04931c2 ("bpf: fix bpf_jit_limit knob for PAGE_SIZE >= 64K")
and thus, a new proc_dolongvec_minmax_bpf_restricted() has been
added.

With this last change, we got back to that
proc_dointvec_minmax_bpf_restricted() is used only under
CONFIG_HAVE_EBPF_JIT, but the corresponding ifdef has not been
brought back.

So, in configurations like CONFIG_BPF_JIT=y && CONFIG_HAVE_EBPF_JIT=n
since v4.20 we have:

  CC      net/core/sysctl_net_core.o
net/core/sysctl_net_core.c:292:1: warning: ‘proc_dointvec_minmax_bpf_restricted’ defined but not used [-Wunused-function]
  292 | proc_dointvec_minmax_bpf_restricted(struct ctl_table *table, int write,
      | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Suppress this by guarding it with CONFIG_HAVE_EBPF_JIT again.

Fixes: fdadd04931c2 ("bpf: fix bpf_jit_limit knob for PAGE_SIZE >= 64K")
Signed-off-by: Alexander Lobakin 
Signed-off-by: Daniel Borkmann 
Link: https://lore.kernel.org/bpf/20191218091821.7080-1-alobakin@dlink.ru
Signed-off-by: Sasha Levin

inet: protect against too small mtu values.

2019-12-21T09:47:38+00:00

[ 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 
Reported-by: syzbot 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: dsa: fix flow dissection on Tx path

2019-12-21T09:47:31+00:00

[ Upstream commit 8bef0af09a5415df761b04fa487a6c34acae74bc ]

Commit 43e665287f93 ("net-next: dsa: fix flow dissection") added an
ability to override protocol and network offset during flow dissection
for DSA-enabled devices (i.e. controllers shipped as switch CPU ports)
in order to fix skb hashing for RPS on Rx path.

However, skb_hash() and added part of code can be invoked not only on
Rx, but also on Tx path if we have a multi-queued device and:
 - kernel is running on UP system or
 - XPS is not configured.

The call stack in this two cases will be like: dev_queue_xmit() ->
__dev_queue_xmit() -> netdev_core_pick_tx() -> netdev_pick_tx() ->
skb_tx_hash() -> skb_get_hash().

The problem is that skbs queued for Tx have both network offset and
correct protocol already set up even after inserting a CPU tag by DSA
tagger, so calling tag_ops->flow_dissect() on this path actually only
breaks flow dissection and hashing.

This can be observed by adding debug prints just before and right after
tag_ops->flow_dissect() call to the related block of code:

Before the patch:

Rx path (RPS):

[   19.240001] Rx: proto: 0x00f8, nhoff: 0	/* ETH_P_XDSA */
[   19.244271] tag_ops->flow_dissect()
[   19.247811] Rx: proto: 0x0800, nhoff: 8	/* ETH_P_IP */

[   19.215435] Rx: proto: 0x00f8, nhoff: 0	/* ETH_P_XDSA */
[   19.219746] tag_ops->flow_dissect()
[   19.223241] Rx: proto: 0x0806, nhoff: 8	/* ETH_P_ARP */

[   18.654057] Rx: proto: 0x00f8, nhoff: 0	/* ETH_P_XDSA */
[   18.658332] tag_ops->flow_dissect()
[   18.661826] Rx: proto: 0x8100, nhoff: 8	/* ETH_P_8021Q */

Tx path (UP system):

[   18.759560] Tx: proto: 0x0800, nhoff: 26	/* ETH_P_IP */
[   18.763933] tag_ops->flow_dissect()
[   18.767485] Tx: proto: 0x920b, nhoff: 34	/* junk */

[   22.800020] Tx: proto: 0x0806, nhoff: 26	/* ETH_P_ARP */
[   22.804392] tag_ops->flow_dissect()
[   22.807921] Tx: proto: 0x920b, nhoff: 34	/* junk */

[   16.898342] Tx: proto: 0x86dd, nhoff: 26	/* ETH_P_IPV6 */
[   16.902705] tag_ops->flow_dissect()
[   16.906227] Tx: proto: 0x920b, nhoff: 34	/* junk */

After:

Rx path (RPS):

[   16.520993] Rx: proto: 0x00f8, nhoff: 0	/* ETH_P_XDSA */
[   16.525260] tag_ops->flow_dissect()
[   16.528808] Rx: proto: 0x0800, nhoff: 8	/* ETH_P_IP */

[   15.484807] Rx: proto: 0x00f8, nhoff: 0	/* ETH_P_XDSA */
[   15.490417] tag_ops->flow_dissect()
[   15.495223] Rx: proto: 0x0806, nhoff: 8	/* ETH_P_ARP */

[   17.134621] Rx: proto: 0x00f8, nhoff: 0	/* ETH_P_XDSA */
[   17.138895] tag_ops->flow_dissect()
[   17.142388] Rx: proto: 0x8100, nhoff: 8	/* ETH_P_8021Q */

Tx path (UP system):

[   15.499558] Tx: proto: 0x0800, nhoff: 26	/* ETH_P_IP */

[   20.664689] Tx: proto: 0x0806, nhoff: 26	/* ETH_P_ARP */

[   18.565782] Tx: proto: 0x86dd, nhoff: 26	/* ETH_P_IPV6 */

In order to fix that we can add the check 'proto == htons(ETH_P_XDSA)'
to prevent code from calling tag_ops->flow_dissect() on Tx.
I also decided to initialize 'offset' variable so tagger callbacks can
now safely leave it untouched without provoking a chaos.

Fixes: 43e665287f93 ("net-next: dsa: fix flow dissection")
Signed-off-by: Alexander Lobakin 
Reviewed-by: Florian Fainelli 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: fix possible overflow in __sk_mem_raise_allocated()

2019-12-05T14:37:58+00:00

[ 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 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net/core/neighbour: fix kmemleak minimal reference count for hash tables

2019-12-05T14:37:55+00:00

[ Upstream commit 01b833ab44c9e484060aad72267fc7e71beb559b ]

This should be 1 for normal allocations, 0 disables leak reporting.

Signed-off-by: Konstantin Khlebnikov 
Reported-by: Cong Wang 
Fixes: 85704cb8dcfd ("net/core/neighbour: tell kmemleak about hash tables")
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net/core/neighbour: tell kmemleak about hash tables

2019-12-05T14:37:54+00:00

[ Upstream commit 85704cb8dcfd88d351bfc87faaeba1c8214f3177 ]

This fixes false-positive kmemleak reports about leaked neighbour entries:

unreferenced object 0xffff8885c6e4d0a8 (size 1024):
  comm "softirq", pid 0, jiffies 4294922664 (age 167640.804s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 20 2c f3 83 ff ff ff ff  ........ ,......
    08 c0 ef 5f 84 88 ff ff 01 8c 7d 02 01 00 00 00  ..._......}.....
  backtrace:
    [<00000000748509fe>] ip6_finish_output2+0x887/0x1e40
    [<0000000036d7a0d8>] ip6_output+0x1ba/0x600
    [<0000000027ea7dba>] ip6_send_skb+0x92/0x2f0
    [<00000000d6e2111d>] udp_v6_send_skb.isra.24+0x680/0x15e0
    [<000000000668a8be>] udpv6_sendmsg+0x18c9/0x27a0
    [<000000004bd5fa90>] sock_sendmsg+0xb3/0xf0
    [<000000008227b29f>] ___sys_sendmsg+0x745/0x8f0
    [<000000008698009d>] __sys_sendmsg+0xde/0x170
    [<00000000889dacf1>] do_syscall_64+0x9b/0x400
    [<0000000081cdb353>] entry_SYSCALL_64_after_hwframe+0x49/0xbe
    [<000000005767ed39>] 0xffffffffffffffff

Signed-off-by: Konstantin Khlebnikov 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net/net_namespace: Check the return value of register_pernet_subsys()

2019-12-05T14:37:48+00:00

[ Upstream commit 0eb987c874dc93f9c9d85a6465dbde20fdd3884c ]

In net_ns_init(), register_pernet_subsys() could fail while registering
network namespace subsystems. The fix checks the return value and
sends a panic() on failure.

Signed-off-by: Aditya Pakki 
Reviewed-by: Kirill Tkhai 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net: do not abort bulk send on BQL status

2019-12-01T08:14:01+00:00

[ Upstream commit fe60faa5063822f2d555f4f326c7dd72a60929bf ]

Before calling dev_hard_start_xmit(), upper layers tried
to cook optimal skb list based on BQL budget.

Problem is that GSO packets can end up comsuming more than
the BQL budget.

Breaking the loop is not useful, since requeued packets
are ahead of any packets still in the qdisc.

It is also more expensive, since next TX completion will
push these packets later, while skbs are not in cpu caches.

It is also a behavior difference with TSO packets, that can
break the BQL limit by a large amount.

Note that drivers should use __netdev_tx_sent_queue()
in order to have optimal xmit_more support, and avoid
useless atomic operations as shown in the following patch.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin