Introduction of bounded loops exposed old bug in x64 JIT.
JIT maintains the array of offsets to the end of all instructions to
compute jmp offsets.
addrs[0] - offset of the end of the 1st insn (that includes prologue).
addrs[1] - offset of the end of the 2nd insn.
JIT didn't keep the offset of the beginning of the 1st insn,
since classic BPF didn't have backward jumps and valid extended BPF
couldn't have a branch to 1st insn, because it didn't allow loops.
With bounded loops it's possible to construct a valid program that
jumps backwards to the 1st insn.
Fix JIT by computing:
addrs[0] - offset of the end of prologue == start of the 1st insn.
addrs[1] - offset of the end of 1st insn.

v1->v2:
- Yonghong noticed a bug in jit linfo.
  Fix it by passing 'addrs + 1' to bpf_prog_fill_jited_linfo(),
  since it expects insn_to_jit_off array to be offsets to last byte.

Reported-by: syzbot+35101610ff3e83119b1b@syzkaller.appspotmail.com
Fixes: 2589726d12a1 ("bpf: introduce bounded loops")
Fixes: 0a14842f5a3c ("net: filter: Just In Time compiler for x86-64")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>

Two cases of overlapping changes, nothing fancy.

Signed-off-by: David S. Miller <davem@davemloft.net>

Daniel Borkmann says:

====================
pull-request: bpf 2019-07-03

The following pull-request contains BPF updates for your *net* tree.

The main changes are:

1) Fix the interpreter to properly handle BPF_ALU32 | BPF_ARSH
   on BE architectures, from Jiong.

2) Fix several bugs in the x32 BPF JIT for handling shifts by 0,
   from Luke and Xi.

3) Fix NULL pointer deref in btf_type_is_resolve_source_only(),
   from Stanislav.

4) Properly handle the check that forwarding is enabled on the device
   in bpf_ipv6_fib_lookup() helper code, from Anton.

5) Fix UAPI bpf_prog_info fields alignment for archs that have 16 bit
   alignment such as m68k, from Baruch.

6) Fix kernel hanging in unregister_netdevice loop while unregistering
   device bound to XDP socket, from Ilya.

7) Properly terminate tail update in xskq_produce_flush_desc(), from Nathan.

8) Fix broken always_inline handling in test_lwt_seg6local, from Jiri.

9) Fix bpftool to use correct argument in cgroup errors, from Jakub.

10) Fix detaching dummy prog in XDP redirect sample code, from Prashant.

11) Add Jonathan to AF_XDP reviewers, from Björn.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

The current x32 BPF JIT does not correctly compile shift operations when
the immediate shift amount is 0. The expected behavior is for this to
be a no-op.

The following program demonstrates the bug. The expexceted result is 1,
but the current JITed code returns 2.

  r0 = 1
  r1 = 1
  r1 <<= 0
  if r1 == 1 goto end
  r0 = 2
end:
  exit

This patch simplifies the code and fixes the bug.

Fixes: 03f5781be2c7 ("bpf, x86_32: add eBPF JIT compiler for ia32")
Co-developed-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Luke Nelson <luke.r.nels@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

The current x32 BPF JIT for shift operations is not correct when the
shift amount in a register is 0. The expected behavior is a no-op, whereas
the current implementation changes bits in the destination register.

The following example demonstrates the bug. The expected result of this
program is 1, but the current JITed code returns 2.

  r0 = 1
  r1 = 1
  r2 = 0
  r1 <<= r2
  if r1 == 1 goto end
  r0 = 2
end:
  exit

The bug is caused by an incorrect assumption by the JIT that a shift by
32 clear the register. On x32 however, shifts use the lower 5 bits of
the source, making a shift by 32 equivalent to a shift by 0.

This patch fixes the bug using double-precision shifts, which also
simplifies the code.

Fixes: 03f5781be2c7 ("bpf, x86_32: add eBPF JIT compiler for ia32")
Co-developed-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Luke Nelson <luke.r.nels@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Honestly all the conflicts were simple overlapping changes,
nothing really interesting to report.

Signed-off-by: David S. Miller <davem@davemloft.net>

Pull networking fixes from David Miller:
 "Lots of bug fixes here:

   1) Out of bounds access in __bpf_skc_lookup, from Lorenz Bauer.

   2) Fix rate reporting in cfg80211_calculate_bitrate_he(), from John
      Crispin.

   3) Use after free in psock backlog workqueue, from John Fastabend.

   4) Fix source port matching in fdb peer flow rule of mlx5, from Raed
      Salem.

   5) Use atomic_inc_not_zero() in fl6_sock_lookup(), from Eric Dumazet.

   6) Network header needs to be set for packet redirect in nfp, from
      John Hurley.

   7) Fix udp zerocopy refcnt, from Willem de Bruijn.

   8) Don't assume linear buffers in vxlan and geneve error handlers,
      from Stefano Brivio.

   9) Fix TOS matching in mlxsw, from Jiri Pirko.

  10) More SCTP cookie memory leak fixes, from Neil Horman.

  11) Fix VLAN filtering in rtl8366, from Linus Walluij.

  12) Various TCP SACK payload size and fragmentation memory limit fixes
      from Eric Dumazet.

  13) Use after free in pneigh_get_next(), also from Eric Dumazet.

  14) LAPB control block leak fix from Jeremy Sowden"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (145 commits)
  lapb: fixed leak of control-blocks.
  tipc: purge deferredq list for each grp member in tipc_group_delete
  ax25: fix inconsistent lock state in ax25_destroy_timer
  neigh: fix use-after-free read in pneigh_get_next
  tcp: fix compile error if !CONFIG_SYSCTL
  hv_sock: Suppress bogus "may be used uninitialized" warnings
  be2net: Fix number of Rx queues used for flow hashing
  net: handle 802.1P vlan 0 packets properly
  tcp: enforce tcp_min_snd_mss in tcp_mtu_probing()
  tcp: add tcp_min_snd_mss sysctl
  tcp: tcp_fragment() should apply sane memory limits
  tcp: limit payload size of sacked skbs
  Revert "net: phylink: set the autoneg state in phylink_phy_change"
  bpf: fix nested bpf tracepoints with per-cpu data
  bpf: Fix out of bounds memory access in bpf_sk_storage
  vsock/virtio: set SOCK_DONE on peer shutdown
  net: dsa: rtl8366: Fix up VLAN filtering
  net: phylink: set the autoneg state in phylink_phy_change
  net: add high_order_alloc_disable sysctl/static key
  tcp: add tcp_tx_skb_cache sysctl
  ...

Since commit 177366bf7ceb the %rbp stopped pointing to %rbp of the
previous stack frame. That broke frame pointer based stack unwinding.
This commit is a partial revert of it.
Note that the location of tail_call_cnt is fixed, since the verifier
enforces MAX_BPF_STACK stack size for programs with tail calls.

Fixes: 177366bf7ceb ("bpf: change x86 JITed program stack layout")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation version 2 of the license

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 315 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190115.503150771@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Cc: Wang YanQing <udknight@gmail.com>
Tested-by: Wang YanQing <udknight@gmail.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>