With gcc-4.1.2:

    net/ipv4/inet_hashtables.c: In function ‘inet_unhash’:
    net/ipv4/inet_hashtables.c:628: warning: ‘ilb’ may be used uninitialized in this function

While this is a false positive, it can easily be avoided by using the
pointer itself as the canary variable.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With gcc-4.1.2.:

    net/bridge/br_fdb.c: In function ‘br_fdb_sync_static’:
    net/bridge/br_fdb.c:996: warning: ‘err’ may be used uninitialized in this function

Indeed, if the list is empty, err will be uninitialized, and will be
propagated up as the function return value.

Fix this by preinitializing err to zero.

Fixes: eb793583 ("net: bridge: use rhashtable for fdbs")
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Acked-by: NNikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

IPv4 and IPv6 packets may arrive with lower-layer padding that is not
included in the L3 length. For example, a short IPv4 packet may have
up to 6 bytes of padding following the IP payload when received on an
Ethernet device with a minimum packet length of 64 bytes.

Higher-layer processing functions in netfilter (e.g. nf_ip_checksum(),
and help() in nf_conntrack_ftp) assume skb->len reflects the length of
the L3 header and payload, rather than referring back to
ip_hdr->tot_len or ipv6_hdr->payload_len, and get confused by
lower-layer padding.

In the normal IPv4 receive path, ip_rcv() trims the packet to
ip_hdr->tot_len before invoking netfilter hooks. In the IPv6 receive
path, ip6_rcv() does the same using ipv6_hdr->payload_len. Similarly
in the br_netfilter receive path, br_validate_ipv4() and
br_validate_ipv6() trim the packet to the L3 length before invoking
netfilter hooks.

Currently in the OVS conntrack receive path, ovs_ct_execute() pulls
the skb to the L3 header but does not trim it to the L3 length before
calling nf_conntrack_in(NF_INET_PRE_ROUTING). When
nf_conntrack_proto_tcp encounters a packet with lower-layer padding,
nf_ip_checksum() fails causing a "nf_ct_tcp: bad TCP checksum" log
message. While extra zero bytes don't affect the checksum, the length
in the IP pseudoheader does. That length is based on skb->len, and
without trimming, it doesn't match the length the sender used when
computing the checksum.

In ovs_ct_execute(), trim the skb to the L3 length before higher-layer
processing.
Signed-off-by: NEd Swierk <eswierk@skyportsystems.com>
Acked-by: NPravin B Shelar <pshelar@ovn.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This commit fixes the pacing_gain to remain at BBR_UNIT (1.0) when
using lt_bw and returning from the PROBE_RTT state to PROBE_BW.

Previously, when using lt_bw, upon exiting PROBE_RTT and entering
PROBE_BW the bbr_reset_probe_bw_mode() code could sometimes randomly
end up with a cycle_idx of 0 and hence have bbr_advance_cycle_phase()
set a pacing gain above 1.0. In such cases this would result in a
pacing rate that is 1.25x higher than intended, potentially resulting
in a high loss rate for a little while until we stop using the lt_bw a
bit later.

This commit is a stable candidate for kernels back as far as 4.9.

Fixes: 0f8782ea ("tcp_bbr: add BBR congestion control")
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Signed-off-by: NSoheil Hassas Yeganeh <soheil@google.com>
Reported-by: NBeyers Cronje <bcronje@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If you take a GSO skb, and split it into packets, will the MAC
length (L2 + L3 + L4 headers + payload) of those packets be small
enough to fit within a given length?

Move skb_gso_mac_seglen() to skbuff.h with other related functions
like skb_gso_network_seglen() so we can use it, and then create
skb_gso_validate_mac_len to do the full calculation.
Signed-off-by: NDaniel Axtens <dja@axtens.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Async crypto accelerators (e.g. drivers/crypto/caam) support offloading
GCM operation. If they are enabled, crypto_aead_encrypt() return error
code -EINPROGRESS. In this case tls_do_encryption() needs to wait on a
completion till the time the response for crypto offload request is
received.
Signed-off-by: NVakul Garg <vakul.garg@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When we dump the ip6mr mfc entries via proc, we initialize an iterator
with the table to dump but we don't clear the cache pointer which might
be initialized from a prior read on the same descriptor that ended. This
can result in lock imbalance (an unnecessary unlock) leading to other
crashes and hangs. Clear the cache pointer like ipmr does to fix the issue.
Thanks for the reliable reproducer.

Here's syzbot's trace:
 WARNING: bad unlock balance detected!
 4.15.0-rc3+ #128 Not tainted
 syzkaller971460/3195 is trying to release lock (mrt_lock) at:
 [<000000006898068d>] ipmr_mfc_seq_stop+0xe1/0x130 net/ipv6/ip6mr.c:553
 but there are no more locks to release!

 other info that might help us debug this:
 1 lock held by syzkaller971460/3195:
  #0:  (&p->lock){+.+.}, at: [<00000000744a6565>] seq_read+0xd5/0x13d0
 fs/seq_file.c:165

 stack backtrace:
 CPU: 1 PID: 3195 Comm: syzkaller971460 Not tainted 4.15.0-rc3+ #128
 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
 Google 01/01/2011
 Call Trace:
  __dump_stack lib/dump_stack.c:17 [inline]
  dump_stack+0x194/0x257 lib/dump_stack.c:53
  print_unlock_imbalance_bug+0x12f/0x140 kernel/locking/lockdep.c:3561
  __lock_release kernel/locking/lockdep.c:3775 [inline]
  lock_release+0x5f9/0xda0 kernel/locking/lockdep.c:4023
  __raw_read_unlock include/linux/rwlock_api_smp.h:225 [inline]
  _raw_read_unlock+0x1a/0x30 kernel/locking/spinlock.c:255
  ipmr_mfc_seq_stop+0xe1/0x130 net/ipv6/ip6mr.c:553
  traverse+0x3bc/0xa00 fs/seq_file.c:135
  seq_read+0x96a/0x13d0 fs/seq_file.c:189
  proc_reg_read+0xef/0x170 fs/proc/inode.c:217
  do_loop_readv_writev fs/read_write.c:673 [inline]
  do_iter_read+0x3db/0x5b0 fs/read_write.c:897
  compat_readv+0x1bf/0x270 fs/read_write.c:1140
  do_compat_preadv64+0xdc/0x100 fs/read_write.c:1189
  C_SYSC_preadv fs/read_write.c:1209 [inline]
  compat_SyS_preadv+0x3b/0x50 fs/read_write.c:1203
  do_syscall_32_irqs_on arch/x86/entry/common.c:327 [inline]
  do_fast_syscall_32+0x3ee/0xf9d arch/x86/entry/common.c:389
  entry_SYSENTER_compat+0x51/0x60 arch/x86/entry/entry_64_compat.S:125
 RIP: 0023:0xf7f73c79
 RSP: 002b:00000000e574a15c EFLAGS: 00000292 ORIG_RAX: 000000000000014d
 RAX: ffffffffffffffda RBX: 000000000000000f RCX: 0000000020a3afb0
 RDX: 0000000000000001 RSI: 0000000000000067 RDI: 0000000000000000
 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 BUG: sleeping function called from invalid context at lib/usercopy.c:25
 in_atomic(): 1, irqs_disabled(): 0, pid: 3195, name: syzkaller971460
 INFO: lockdep is turned off.
 CPU: 1 PID: 3195 Comm: syzkaller971460 Not tainted 4.15.0-rc3+ #128
 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
 Google 01/01/2011
 Call Trace:
  __dump_stack lib/dump_stack.c:17 [inline]
  dump_stack+0x194/0x257 lib/dump_stack.c:53
  ___might_sleep+0x2b2/0x470 kernel/sched/core.c:6060
  __might_sleep+0x95/0x190 kernel/sched/core.c:6013
  __might_fault+0xab/0x1d0 mm/memory.c:4525
  _copy_to_user+0x2c/0xc0 lib/usercopy.c:25
  copy_to_user include/linux/uaccess.h:155 [inline]
  seq_read+0xcb4/0x13d0 fs/seq_file.c:279
  proc_reg_read+0xef/0x170 fs/proc/inode.c:217
  do_loop_readv_writev fs/read_write.c:673 [inline]
  do_iter_read+0x3db/0x5b0 fs/read_write.c:897
  compat_readv+0x1bf/0x270 fs/read_write.c:1140
  do_compat_preadv64+0xdc/0x100 fs/read_write.c:1189
  C_SYSC_preadv fs/read_write.c:1209 [inline]
  compat_SyS_preadv+0x3b/0x50 fs/read_write.c:1203
  do_syscall_32_irqs_on arch/x86/entry/common.c:327 [inline]
  do_fast_syscall_32+0x3ee/0xf9d arch/x86/entry/common.c:389
  entry_SYSENTER_compat+0x51/0x60 arch/x86/entry/entry_64_compat.S:125
 RIP: 0023:0xf7f73c79
 RSP: 002b:00000000e574a15c EFLAGS: 00000292 ORIG_RAX: 000000000000014d
 RAX: ffffffffffffffda RBX: 000000000000000f RCX: 0000000020a3afb0
 RDX: 0000000000000001 RSI: 0000000000000067 RDI: 0000000000000000
 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 WARNING: CPU: 1 PID: 3195 at lib/usercopy.c:26 _copy_to_user+0xb5/0xc0
 lib/usercopy.c:26
Reported-by: Nsyzbot <bot+eceb3204562c41a438fa1f2335e0fe4f6886d669@syzkaller.appspotmail.com>
Signed-off-by: NNikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Blank help texts are probably either a typo, a Kconfig misunderstanding,
or some kind of half-committing to adding a help text (in which case a
TODO comment would be clearer, if the help text really can't be added
right away).

Best to remove them, IMO.
Signed-off-by: NUlf Magnusson <ulfalizer@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add suffix LL to constant 1000 in order to give the compiler
complete information about the proper arithmetic to use. Notice
that this constant is used in a context that expects an expression
of type long long int (64 bits, signed).

The expression (band->burst_size + band->rate) * 1000 is currently
being evaluated using 32-bit arithmetic.

Addresses-Coverity-ID: 1461563 ("Unintentional integer overflow")
Signed-off-by: NGustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add suffix ULL to constant 80000 in order to avoid a potential integer
overflow and give the compiler complete information about the proper
arithmetic to use. Notice that this constant is used in a context that
expects an expression of type u64.

The current cast to u64 effectively applies to the whole expression
as an argument of type u64 to be passed to div64_u64, but it does
not prevent it from being evaluated using 32-bit arithmetic instead
of 64-bit arithmetic.

Also, once the expression is properly evaluated using 64-bit arithmentic,
there is no need for the parentheses and the external cast to u64.

Addresses-Coverity-ID: 1357588 ("Unintentional integer overflow")
Signed-off-by: NGustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

- Backwards Compatibility:
  If userspace wants to determine whether RTM_NEWLINK supports the
  IFLA_IF_NETNSID property they should first send an RTM_GETLINK request
  with IFLA_IF_NETNSID on lo. If either EACCESS is returned or the reply
  does not include IFLA_IF_NETNSID userspace should assume that
  IFLA_IF_NETNSID is not supported on this kernel.
  If the reply does contain an IFLA_IF_NETNSID property userspace
  can send an RTM_NEWLINK with a IFLA_IF_NETNSID property. If they receive
  EOPNOTSUPP then the kernel does not support the IFLA_IF_NETNSID property
  with RTM_NEWLINK. Userpace should then fallback to other means.

- Security:
  Callers must have CAP_NET_ADMIN in the owning user namespace of the
  target network namespace.
Signed-off-by: NChristian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ipmr_vif_seq_show() prints the difference between two pointers with the
format string %2zd (z for size_t), however the correct format string is
%2td instead (t for ptrdiff_t).

The same bug in ip6mr_vif_seq_show() was already fixed long ago by
commit d430a227 ("bogus format in ip6mr").
Signed-off-by: NJames Hogan <jhogan@kernel.org>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: netdev@vger.kernel.org
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

socket can be disconnected and gets transformed back to a listening
socket, if sk_frag.page is not released, which will be cloned into
a new socket by sk_clone_lock, but the reference count of this page
is increased, lead to a use after free or double free issue
Signed-off-by: NLi RongQing <lirongqing@baidu.com>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When using ioctl to get address of interface, we can't
get it anymore. For example, the command is show as below.

	# ifconfig eth0

In the patch ("03aef17b"), the devinet_ioctl does not
return a suitable value, even though we can find it in
the kernel. Then fix it now.

Fixes: 03aef17b ("devinet_ioctl(): take copyin/copyout to caller")
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NTonghao Zhang <xiangxia.m.yue@gmail.com>
Acked-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

syzbot reported a lockdep splat in gen_new_estimator() /
est_fetch_counters() when attempting to lock est->stats_lock.

Since est_fetch_counters() is called from BH context from timer
interrupt, we need to block BH as well when calling it from process
context.

Most qdiscs use per cpu counters and are immune to the problem,
but net/sched/act_api.c and net/netfilter/xt_RATEEST.c are using
a spinlock to protect their data. They both call gen_new_estimator()
while object is created and not yet alive, so this bug could
not trigger a deadlock, only a lockdep splat.

Fixes: 1c0d32fd ("net_sched: gen_estimator: complete rewrite of rate estimators")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: Nsyzbot <syzkaller@googlegroups.com>
Acked-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Heiner reported a lockdep splat [1]

This is caused by attempting GFP_KERNEL allocation while RCU lock is
held and BH blocked.

We believe that addrconf_verify_rtnl() could run for a long period,
so instead of using GFP_ATOMIC here as Ido suggested, we should break
the critical section and restart it after the allocation.

[1]
[86220.125562] =============================
[86220.125586] WARNING: suspicious RCU usage
[86220.125612] 4.15.0-rc7-next-20180110+ #7 Not tainted
[86220.125641] -----------------------------
[86220.125666] kernel/sched/core.c:6026 Illegal context switch in RCU-bh read-side critical section!
[86220.125711]
               other info that might help us debug this:

[86220.125755]
               rcu_scheduler_active = 2, debug_locks = 1
[86220.125792] 4 locks held by kworker/0:2/1003:
[86220.125817]  #0:  ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<00000000da8e9b73>] process_one_work+0x1de/0x680
[86220.125895]  #1:  ((addr_chk_work).work){+.+.}, at: [<00000000da8e9b73>] process_one_work+0x1de/0x680
[86220.125959]  #2:  (rtnl_mutex){+.+.}, at: [<00000000b06d9510>] rtnl_lock+0x12/0x20
[86220.126017]  #3:  (rcu_read_lock_bh){....}, at: [<00000000aef52299>] addrconf_verify_rtnl+0x1e/0x510 [ipv6]
[86220.126111]
               stack backtrace:
[86220.126142] CPU: 0 PID: 1003 Comm: kworker/0:2 Not tainted 4.15.0-rc7-next-20180110+ #7
[86220.126185] Hardware name: ZOTAC ZBOX-CI321NANO/ZBOX-CI321NANO, BIOS B246P105 06/01/2015
[86220.126250] Workqueue: ipv6_addrconf addrconf_verify_work [ipv6]
[86220.126288] Call Trace:
[86220.126312]  dump_stack+0x70/0x9e
[86220.126337]  lockdep_rcu_suspicious+0xce/0xf0
[86220.126365]  ___might_sleep+0x1d3/0x240
[86220.126390]  __might_sleep+0x45/0x80
[86220.126416]  kmem_cache_alloc_trace+0x53/0x250
[86220.126458]  ? ipv6_add_addr+0xfe/0x6e0 [ipv6]
[86220.126498]  ipv6_add_addr+0xfe/0x6e0 [ipv6]
[86220.126538]  ipv6_create_tempaddr+0x24d/0x430 [ipv6]
[86220.126580]  ? ipv6_create_tempaddr+0x24d/0x430 [ipv6]
[86220.126623]  addrconf_verify_rtnl+0x339/0x510 [ipv6]
[86220.126664]  ? addrconf_verify_rtnl+0x339/0x510 [ipv6]
[86220.126708]  addrconf_verify_work+0xe/0x20 [ipv6]
[86220.126738]  process_one_work+0x258/0x680
[86220.126765]  worker_thread+0x35/0x3f0
[86220.126790]  kthread+0x124/0x140
[86220.126813]  ? process_one_work+0x680/0x680
[86220.126839]  ? kthread_create_worker_on_cpu+0x40/0x40
[86220.126869]  ? umh_complete+0x40/0x40
[86220.126893]  ? call_usermodehelper_exec_async+0x12a/0x160
[86220.126926]  ret_from_fork+0x4b/0x60
[86220.126999] BUG: sleeping function called from invalid context at mm/slab.h:420
[86220.127041] in_atomic(): 1, irqs_disabled(): 0, pid: 1003, name: kworker/0:2
[86220.127082] 4 locks held by kworker/0:2/1003:
[86220.127107]  #0:  ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<00000000da8e9b73>] process_one_work+0x1de/0x680
[86220.127179]  #1:  ((addr_chk_work).work){+.+.}, at: [<00000000da8e9b73>] process_one_work+0x1de/0x680
[86220.127242]  #2:  (rtnl_mutex){+.+.}, at: [<00000000b06d9510>] rtnl_lock+0x12/0x20
[86220.127300]  #3:  (rcu_read_lock_bh){....}, at: [<00000000aef52299>] addrconf_verify_rtnl+0x1e/0x510 [ipv6]
[86220.127414] CPU: 0 PID: 1003 Comm: kworker/0:2 Not tainted 4.15.0-rc7-next-20180110+ #7
[86220.127463] Hardware name: ZOTAC ZBOX-CI321NANO/ZBOX-CI321NANO, BIOS B246P105 06/01/2015
[86220.127528] Workqueue: ipv6_addrconf addrconf_verify_work [ipv6]
[86220.127568] Call Trace:
[86220.127591]  dump_stack+0x70/0x9e
[86220.127616]  ___might_sleep+0x14d/0x240
[86220.127644]  __might_sleep+0x45/0x80
[86220.127672]  kmem_cache_alloc_trace+0x53/0x250
[86220.127717]  ? ipv6_add_addr+0xfe/0x6e0 [ipv6]
[86220.127762]  ipv6_add_addr+0xfe/0x6e0 [ipv6]
[86220.127807]  ipv6_create_tempaddr+0x24d/0x430 [ipv6]
[86220.127854]  ? ipv6_create_tempaddr+0x24d/0x430 [ipv6]
[86220.127903]  addrconf_verify_rtnl+0x339/0x510 [ipv6]
[86220.127950]  ? addrconf_verify_rtnl+0x339/0x510 [ipv6]
[86220.127998]  addrconf_verify_work+0xe/0x20 [ipv6]
[86220.128032]  process_one_work+0x258/0x680
[86220.128063]  worker_thread+0x35/0x3f0
[86220.128091]  kthread+0x124/0x140
[86220.128117]  ? process_one_work+0x680/0x680
[86220.128146]  ? kthread_create_worker_on_cpu+0x40/0x40
[86220.128180]  ? umh_complete+0x40/0x40
[86220.128207]  ? call_usermodehelper_exec_async+0x12a/0x160
[86220.128243]  ret_from_fork+0x4b/0x60

Fixes: f3d9832e ("ipv6: addrconf: cleanup locking in ipv6_add_addr")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: NHeiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In current route cache aging logic, if a route has both RTF_EXPIRE and
RTF_GATEWAY set, the route will only be removed if the neighbor cache
has no NTF_ROUTER flag. Otherwise, even if the route has expired, it
won't get deleted.
Fix this logic to always check if the route has expired first and then
do the gateway neighbor cache check if previous check decide to not
remove the exception entry.

Fixes: 1859bac0 ("ipv6: remove from fib tree aged out RTF_CACHE dst")
Signed-off-by: NWei Wang <weiwan@google.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Acked-by: NMartin KaFai Lau <kafai@fb.com>
Acked-by: NPaolo Abeni <pabeni@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Unsolicited IPv6 neighbor advertisements should be sent after DAD
completes. Update ndisc_send_unsol_na to skip tentative, non-optimistic
addresses and have those sent by addrconf_dad_completed after DAD.

Fixes: 4a6e3c5d ("net: ipv6: send unsolicited NA on admin up")
Reported-by: NVivek Venkatraman <vivek@cumulusnetworks.com>
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

pfifo_fast used to drop based on qdisc_dev(qdisc)->tx_queue_len,
so we have to resize skb array when we change tx_queue_len.

Other qdiscs which read tx_queue_len are fine because they
all save it to sch->limit or somewhere else in qdisc during init.
They don't have to implement this, it is nicer if they do so
that users don't have to re-configure qdisc after changing
tx_queue_len.

Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Introduce a new qdisc ops ->change_tx_queue_len() so that
each qdisc could decide how to implement this if it wants.
Previously we simply read dev->tx_queue_len, after pfifo_fast
switches to skb array, we need this API to resize the skb array
when we change dev->tx_queue_len.

To avoid handling race conditions with TX BH, we need to
deactivate all TX queues before change the value and bring them
back after we are done, this also makes implementation easier.

Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch promotes the local change_tx_queue_len() to a core
helper function, dev_change_tx_queue_len(), so that rtnetlink
and net-sysfs could share the code. This also prepares for the
following patch.

Note, the -EFAULT in the original code doesn't make sense,
we should propagate the errno from notifiers.

Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The goal is to let the user follow an interface that moves to another
netns.

CC: Jiri Benc <jbenc@redhat.com>
CC: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: NJiri Benc <jbenc@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The user should be able to follow any interface that moves to another
netns.  There is no reason to hide physical interfaces.

CC: Jiri Benc <jbenc@redhat.com>
CC: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: NJiri Benc <jbenc@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If a sk_v6_rcv_saddr is !IPV6_ADDR_ANY and !IPV6_ADDR_MAPPED, it
implicitly implies it is an ipv6only socket.  However, in inet6_bind(),
this addr_type checking and setting sk->sk_ipv6only to 1 are only done
after sk->sk_prot->get_port(sk, snum) has been completed successfully.

This inconsistency between sk_v6_rcv_saddr and sk_ipv6only confuses
the 'get_port()'.

In particular, when binding SO_REUSEPORT UDP sockets,
udp_reuseport_add_sock(sk,...) is called.  udp_reuseport_add_sock()
checks "ipv6_only_sock(sk2) == ipv6_only_sock(sk)" before adding sk to
sk2->sk_reuseport_cb.  In this case, ipv6_only_sock(sk2) could be
1 while ipv6_only_sock(sk) is still 0 here.  The end result is,
reuseport_alloc(sk) is called instead of adding sk to the existing
sk2->sk_reuseport_cb.

It can be reproduced by binding two SO_REUSEPORT UDP sockets on an
IPv6 address (!ANY and !MAPPED).  Only one of the socket will
receive packet.

The fix is to set the implicit sk_ipv6only before calling get_port().
The original sk_ipv6only has to be saved such that it can be restored
in case get_port() failed.  The situation is similar to the
inet_reset_saddr(sk) after get_port() has failed.

Thanks to Calvin Owens <calvinowens@fb.com> who created an easy
reproduction which leads to a fix.

Fixes: e32ea7e7 ("soreuseport: fast reuseport UDP socket selection")
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

- Backwards Compatibility:
  If userspace wants to determine whether RTM_DELLINK supports the
  IFLA_IF_NETNSID property they should first send an RTM_GETLINK request
  with IFLA_IF_NETNSID on lo. If either EACCESS is returned or the reply
  does not include IFLA_IF_NETNSID userspace should assume that
  IFLA_IF_NETNSID is not supported on this kernel.
  If the reply does contain an IFLA_IF_NETNSID property userspace
  can send an RTM_DELLINK with a IFLA_IF_NETNSID property. If they receive
  EOPNOTSUPP then the kernel does not support the IFLA_IF_NETNSID property
  with RTM_DELLINK. Userpace should then fallback to other means.

- Security:
  Callers must have CAP_NET_ADMIN in the owning user namespace of the
  target network namespace.
Signed-off-by: NChristian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

- Backwards Compatibility:
  If userspace wants to determine whether RTM_SETLINK supports the
  IFLA_IF_NETNSID property they should first send an RTM_GETLINK request
  with IFLA_IF_NETNSID on lo. If either EACCESS is returned or the reply
  does not include IFLA_IF_NETNSID userspace should assume that
  IFLA_IF_NETNSID is not supported on this kernel.
  If the reply does contain an IFLA_IF_NETNSID property userspace
  can send an RTM_SETLINK with a IFLA_IF_NETNSID property. If they receive
  EOPNOTSUPP then the kernel does not support the IFLA_IF_NETNSID property
  with RTM_SETLINK. Userpace should then fallback to other means.

  To retain backwards compatibility the kernel will first check whether a
  IFLA_NET_NS_PID or IFLA_NET_NS_FD property has been passed. If either
  one is found it will be used to identify the target network namespace.
  This implies that users who do not care whether their running kernel
  supports IFLA_IF_NETNSID with RTM_SETLINK can pass both
  IFLA_NET_NS_{FD,PID} and IFLA_IF_NETNSID referring to the same network
  namespace.

- Security:
  Callers must have CAP_NET_ADMIN in the owning user namespace of the
  target network namespace.
Signed-off-by: NChristian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

RTM_{NEW,SET}LINK already allow operations on other network namespaces
by identifying the target network namespace through IFLA_NET_NS_{FD,PID}
properties. This is done by looking for the corresponding properties in
do_setlink(). Extend do_setlink() to also look for the IFLA_IF_NETNSID
property. This introduces no functional changes since all callers of
do_setlink() currently block IFLA_IF_NETNSID by reporting an error before
they reach do_setlink().

This introduces the helpers:

static struct net *rtnl_link_get_net_by_nlattr(struct net *src_net, struct
                                               nlattr *tb[])

static struct net *rtnl_link_get_net_capable(const struct sk_buff *skb,
                                             struct net *src_net,
					     struct nlattr *tb[], int cap)

to simplify permission checks and target network namespace retrieval for
RTM_* requests that already support IFLA_NET_NS_{FD,PID} but get extended
to IFLA_IF_NETNSID. To perserve backwards compatibility the helpers look
for IFLA_NET_NS_{FD,PID} properties first before checking for
IFLA_IF_NETNSID.
Signed-off-by: NChristian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

One of the ugly leftovers from the early eBPF days is that div/mod
operations based on registers have a hard-coded src_reg == 0 test
in the interpreter as well as in JIT code generators that would
return from the BPF program with exit code 0. This was basically
adopted from cBPF interpreter for historical reasons.

There are multiple reasons why this is very suboptimal and prone
to bugs. To name one: the return code mapping for such abnormal
program exit of 0 does not always match with a suitable program
type's exit code mapping. For example, '0' in tc means action 'ok'
where the packet gets passed further up the stack, which is just
undesirable for such cases (e.g. when implementing policy) and
also does not match with other program types.

While trying to work out an exception handling scheme, I also
noticed that programs crafted like the following will currently
pass the verifier:

  0: (bf) r6 = r1
  1: (85) call pc+8
  caller:
   R6=ctx(id=0,off=0,imm=0) R10=fp0,call_-1
  callee:
   frame1: R1=ctx(id=0,off=0,imm=0) R10=fp0,call_1
  10: (b4) (u32) r2 = (u32) 0
  11: (b4) (u32) r3 = (u32) 1
  12: (3c) (u32) r3 /= (u32) r2
  13: (61) r0 = *(u32 *)(r1 +76)
  14: (95) exit
  returning from callee:
   frame1: R0_w=pkt(id=0,off=0,r=0,imm=0)
           R1=ctx(id=0,off=0,imm=0) R2_w=inv0
           R3_w=inv(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff))
           R10=fp0,call_1
  to caller at 2:
   R0_w=pkt(id=0,off=0,r=0,imm=0) R6=ctx(id=0,off=0,imm=0)
   R10=fp0,call_-1

  from 14 to 2: R0=pkt(id=0,off=0,r=0,imm=0)
                R6=ctx(id=0,off=0,imm=0) R10=fp0,call_-1
  2: (bf) r1 = r6
  3: (61) r1 = *(u32 *)(r1 +80)
  4: (bf) r2 = r0
  5: (07) r2 += 8
  6: (2d) if r2 > r1 goto pc+1
   R0=pkt(id=0,off=0,r=8,imm=0) R1=pkt_end(id=0,off=0,imm=0)
   R2=pkt(id=0,off=8,r=8,imm=0) R6=ctx(id=0,off=0,imm=0)
   R10=fp0,call_-1
  7: (71) r0 = *(u8 *)(r0 +0)
  8: (b7) r0 = 1
  9: (95) exit

  from 6 to 8: safe
  processed 16 insns (limit 131072), stack depth 0+0

Basically what happens is that in the subprog we make use of a
div/mod by 0 exception and in the 'normal' subprog's exit path
we just return skb->data back to the main prog. This has the
implication that the verifier thinks we always get a pkt pointer
in R0 while we still have the implicit 'return 0' from the div
as an alternative unconditional return path earlier. Thus, R0
then contains 0, meaning back in the parent prog we get the
address range of [0x0, skb->data_end] as read and writeable.
Similar can be crafted with other pointer register types.

Since i) BPF_ABS/IND is not allowed in programs that contain
BPF to BPF calls (and generally it's also disadvised to use in
native eBPF context), ii) unknown opcodes don't return zero
anymore, iii) we don't return an exception code in dead branches,
the only last missing case affected and to fix is the div/mod
handling.

What we would really need is some infrastructure to propagate
exceptions all the way to the original prog unwinding the
current stack and returning that code to the caller of the
BPF program. In user space such exception handling for similar
runtimes is typically implemented with setjmp(3) and longjmp(3)
as one possibility which is not available in the kernel,
though (kgdb used to implement it in kernel long time ago). I
implemented a PoC exception handling mechanism into the BPF
interpreter with porting setjmp()/longjmp() into x86_64 and
adding a new internal BPF_ABRT opcode that can use a program
specific exception code for all exception cases we have (e.g.
div/mod by 0, unknown opcodes, etc). While this seems to work
in the constrained BPF environment (meaning, here, we don't
need to deal with state e.g. from memory allocations that we
would need to undo before going into exception state), it still
has various drawbacks: i) we would need to implement the
setjmp()/longjmp() for every arch supported in the kernel and
for x86_64, arm64, sparc64 JITs currently supporting calls,
ii) it has unconditional additional cost on main program
entry to store CPU register state in initial setjmp() call,
and we would need some way to pass the jmp_buf down into
___bpf_prog_run() for main prog and all subprogs, but also
storing on stack is not really nice (other option would be
per-cpu storage for this, but it also has the drawback that
we need to disable preemption for every BPF program types).
All in all this approach would add a lot of complexity.

Another poor-man's solution would be to have some sort of
additional shared register or scratch buffer to hold state
for exceptions, and test that after every call return to
chain returns and pass R0 all the way down to BPF prog caller.
This is also problematic in various ways: i) an additional
register doesn't map well into JITs, and some other scratch
space could only be on per-cpu storage, which, again has the
side-effect that this only works when we disable preemption,
or somewhere in the input context which is not available
everywhere either, and ii) this adds significant runtime
overhead by putting conditionals after each and every call,
as well as implementation complexity.

Yet another option is to teach verifier that div/mod can
return an integer, which however is also complex to implement
as verifier would need to walk such fake 'mov r0,<code>; exit;'
sequeuence and there would still be no guarantee for having
propagation of this further down to the BPF caller as proper
exception code. For parent prog, it is also is not distinguishable
from a normal return of a constant scalar value.

The approach taken here is a completely different one with
little complexity and no additional overhead involved in
that we make use of the fact that a div/mod by 0 is undefined
behavior. Instead of bailing out, we adapt the same behavior
as on some major archs like ARMv8 [0] into eBPF as well:
X div 0 results in 0, and X mod 0 results in X. aarch64 and
aarch32 ISA do not generate any traps or otherwise aborts
of program execution for unsigned divides. I verified this
also with a test program compiled by gcc and clang, and the
behavior matches with the spec. Going forward we adapt the
eBPF verifier to emit such rewrites once div/mod by register
was seen. cBPF is not touched and will keep existing 'return 0'
semantics. Given the options, it seems the most suitable from
all of them, also since major archs have similar schemes in
place. Given this is all in the realm of undefined behavior,
we still have the option to adapt if deemed necessary and
this way we would also have the option of more flexibility
from LLVM code generation side (which is then fully visible
to verifier). Thus, this patch i) fixes the panic seen in
above program and ii) doesn't bypass the verifier observations.

  [0] ARM Architecture Reference Manual, ARMv8 [ARM DDI 0487B.b]
      http://infocenter.arm.com/help/topic/com.arm.doc.ddi0487b.b/DDI0487B_b_armv8_arm.pdf
      1) aarch64 instruction set: section C3.4.7 and C6.2.279 (UDIV)
         "A division by zero results in a zero being written to
          the destination register, without any indication that
          the division by zero occurred."
      2) aarch32 instruction set: section F1.4.8 and F5.1.263 (UDIV)
         "For the SDIV and UDIV instructions, division by zero
          always returns a zero result."

Fixes: f4d7e40a ("bpf: introduce function calls (verification)")
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

Very minor optimization; saves 1 byte per program in x86_64
JIT in cBPF prologue.
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

select(2) with wfds but no rfds must return when the socket is shut down
by the peer.  This way userspace notices socket activity and gets -EPIPE
from the next write(2).

Currently select(2) does not return for virtio-vsock when a SEND+RCV
shutdown packet is received.  This is because vsock_poll() only sets
POLLOUT | POLLWRNORM for TCP_CLOSE, not the TCP_CLOSING state that the
socket is in when the shutdown is received.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ccid2_hc_tx_rto_expire() timer callback always restarts the timer
again and can run indefinitely (unless it is stopped outside), and after
commit 120e9dab ("dccp: defer ccid_hc_tx_delete() at dismantle time"),
which moved ccid_hc_tx_delete() (also includes sk_stop_timer()) from
dccp_destroy_sock() to sk_destruct(), this started to happen quite often.
The timer prevents releasing the socket, as a result, sk_destruct() won't
be called.

Found with LTP/dccp_ipsec tests running on the bonding device,
which later couldn't be unloaded after the tests were completed:

  unregister_netdevice: waiting for bond0 to become free. Usage count = 148

Fixes: 2a91aa39 ("[DCCP] CCID2: Initial CCID2 (TCP-Like) implementation")
Signed-off-by: NAlexey Kodanev <alexey.kodanev@oracle.com>
Reviewed-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Return statements in functions returning bool should use
true/false instead of 1/0.

This issue was detected with the help of Coccinelle.
Signed-off-by: NGustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: NUrsula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Closing a listen socket may hit the warning
WARN_ON(sock_owned_by_user(sk)) of tcp_close(), if the wake up of
the smc_tcp_listen_worker has not yet finished.
This patch introduces smc_close_wait_listen_clcsock() making sure
the listening internal clcsock has been closed in smc_tcp_listen_work(),
before the listening external SMC socket finishes closing.
Signed-off-by: NUrsula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Proper socket refcounting makes the sock_put worker obsolete.
Signed-off-by: NUrsula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Increase the socket refcount during poll wait.
Take the socket lock before checking socket state.
For a listening socket return a mask independent of state SMC_ACTIVE and
cover errors or closed state as well.
Get rid of the accept_q loop in smc_accept_poll().
Signed-off-by: NUrsula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

RoCE device changes cause an IB event, processed in the global event
handler for the ROCE device. Problems for a certain Queue Pair cause a QP
event, processed in the QP event handler for this QP.
Among those events are port errors and other fatal device errors. All
link groups using such a port or device must be terminated in those cases.
Signed-off-by: NUrsula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Similar to IPv4 allow routes to be added with the RTNH_F_ONLINK flag.
The onlink option requires a gateway and a nexthop device. Any unicast
gateway is allowed (including IPv4 mapped addresses and unresolved
ones) as long as the gateway is not a local address and if it resolves
it must match the given device.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

onlink verification needs to do a lookup in potentially different
table than the table in fib6_config and without the RT6_LOOKUP_F_IFACE
flag. Change ip6_nh_lookup_table to take table id and flags as input
arguments. Both verifications want to ignore link state, so add that
flag can stay in the lookup helper.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Move existing code to validate nexthop into a helper. Follow on patch
adds support for nexthops marked with onlink, and this helper keeps
the complexity of ip6_route_info_create in check.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The kernel documentation is now restructured text. Convert the SocketCAN
documentation and include it in the toplevel kernel documentation.

This patch doesn't do any content change.

All references to can.txt in the code are converted to can.rst.
Signed-off-by: NRobert Schwebel <r.schwebel@pengutronix.de>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>