verifier/ctx_skb.c:708:11: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides]
        .flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Signed-off-by: NStanislav Fomichev <sdf@google.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Use standard C99 %zu for sizeof, not GCC's custom %Zu:
bpf_obj_id.c:76:48: warning: invalid conversion specifier 'Z'
Signed-off-by: NStanislav Fomichev <sdf@google.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

flow_dissector_load.c:55:19: warning: format string is not a string literal (potentially insecure)
      [-Wformat-security]
                error(1, errno, command);
                                ^~~~~~~
flow_dissector_load.c:55:19: note: treat the string as an argument to avoid this
                error(1, errno, command);
                                ^
                                "%s",
1 warning generated.
Signed-off-by: NStanislav Fomichev <sdf@google.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

This makes sure we don't put headers as input files when doing
compilation, because clang complains about the following:

clang-9: error: cannot specify -o when generating multiple output files
../lib.mk:152: recipe for target 'xxx/tools/testing/selftests/bpf/test_verifier' failed
make: *** [xxx/tools/testing/selftests/bpf/test_verifier] Error 1
make: *** Waiting for unfinished jobs....
clang-9: error: cannot specify -o when generating multiple output files
../lib.mk:152: recipe for target 'xxx/tools/testing/selftests/bpf/test_progs' failed
Signed-off-by: NStanislav Fomichev <sdf@google.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

For multiple dimensional arrays like below,
  int a[2][3]
both llvm and pahole generated one BTF_KIND_ARRAY type like
  . element_type: int
  . index_type: unsigned int
  . number of elements: 6

Such a collapsed BTF_KIND_ARRAY type will cause the divergence
in BTF vs. the user code. In the compile-once-run-everywhere
project, the header file is generated from BTF and used for bpf
program, and the definition in the header file will be different
from what user expects.

But the kernel actually supports chained multi-dimensional array
types properly. The above "int a[2][3]" can be represented as
  Type #n:
    . element_type: int
    . index_type: unsigned int
    . number of elements: 3
  Type #(n+1):
    . element_type: type #n
    . index_type: unsigned int
    . number of elements: 2

The following llvm commit
  https://reviews.llvm.org/rL357215
also enables llvm to generated proper chained multi-dimensional arrays.

The test_btf already has a raw test ("struct test #1") for chained
multi-dimensional arrays. This patch added amended bpffs test for
chained multi-dimensional arrays.
Acked-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NYonghong Song <yhs@fb.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Test different scenarios of indirect variable-offset stack access: out of
bound access (>0), min_off below initialized part of the stack,
max_off+size above initialized part of the stack, initialized stack.

Example of output:
  ...
  #856/p indirect variable-offset stack access, out of bound OK
  #857/p indirect variable-offset stack access, max_off+size > max_initialized OK
  #858/p indirect variable-offset stack access, min_off < min_initialized OK
  #859/p indirect variable-offset stack access, ok OK
  ...
Signed-off-by: NAndrey Ignatov <rdna@fb.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

Generate a libbpf.pc file at build time so that users can rely
on pkg-config to find the library, its CFLAGS and LDFLAGS.
Signed-off-by: NLuca Boccassi <bluca@debian.org>
Acked-by: NAndrey Ignatov <rdna@fb.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

When running stacktrace_build_id_nmi, try to query
kernel.perf_event_max_sample_rate sysctl and use it as a sample_freq.
If there was an error reading sysctl, fallback to 5000.

kernel.perf_event_max_sample_rate sysctl can drift and/or can be
adjusted by the perf tool, so assuming a fixed number might be
problematic on a long running machine.
Signed-off-by: NStanislav Fomichev <sdf@google.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

test_tc_tunnel.sh sets up a pair of namespaces connected by a
veth pair to verify encap/decap using bpf_skb_adjust_room.  In
testing this, it uses tunnel links as the peer of the bpf-based
encap/decap.  However because the same IP header is used for inner
and outer IP, when packets arrive at the tunnel interface they will
be dropped by reverse path filtering as those packets are expected
on the veth interface (where the destination IP of the decapped
packet is configured).

To avoid this, ensure reverse path filtering is disabled for the
namespace using tunneling.

Fixes: 98cdabcd ("selftests/bpf: bpf tunnel encap test")
Signed-off-by: NAlan Maguire <alan.maguire@oracle.com>
Acked-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

The current documentation suggests that we would need to bump the
libbpf version on every change. Lets clarify this a bit more and
reflect what we do today in practice, that is, bumping it once per
development cycle.

Fixes: 76d1b894 ("libbpf: Document API and ABI conventions")
Reported-by: NStanislav Fomichev <sdf@google.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

Even though libbpf's versioning script for the linker (libbpf.map)
is pointing to 0.0.2, the BPF_EXTRAVERSION in the Makefile has
not been updated along with it and is therefore still on 0.0.1.

While fixing up, I also noticed that the generated shared object
versioning information is missing, typical convention is to have
a linker name (libbpf.so), soname (libbpf.so.0) and real name
(libbpf.so.0.0.2) for library management. This is based upon the
LIBBPF_VERSION as well.

The build will then produce the following bpf libraries:

  # ll libbpf*
  libbpf.a
  libbpf.so -> libbpf.so.0.0.2
  libbpf.so.0 -> libbpf.so.0.0.2
  libbpf.so.0.0.2

  # readelf -d libbpf.so.0.0.2 | grep SONAME
  0x000000000000000e (SONAME)             Library soname: [libbpf.so.0]

And install them accordingly:

  # rm -rf /tmp/bld; mkdir /tmp/bld; make -j$(nproc) O=/tmp/bld install

  Auto-detecting system features:
  ...                        libelf: [ on  ]
  ...                           bpf: [ on  ]

    CC       /tmp/bld/libbpf.o
    CC       /tmp/bld/bpf.o
    CC       /tmp/bld/nlattr.o
    CC       /tmp/bld/btf.o
    CC       /tmp/bld/libbpf_errno.o
    CC       /tmp/bld/str_error.o
    CC       /tmp/bld/netlink.o
    CC       /tmp/bld/bpf_prog_linfo.o
    CC       /tmp/bld/libbpf_probes.o
    CC       /tmp/bld/xsk.o
    LD       /tmp/bld/libbpf-in.o
    LINK     /tmp/bld/libbpf.a
    LINK     /tmp/bld/libbpf.so.0.0.2
    LINK     /tmp/bld/test_libbpf
    INSTALL  /tmp/bld/libbpf.a
    INSTALL  /tmp/bld/libbpf.so.0.0.2

  # ll /usr/local/lib64/libbpf.*
  /usr/local/lib64/libbpf.a
  /usr/local/lib64/libbpf.so -> libbpf.so.0.0.2
  /usr/local/lib64/libbpf.so.0 -> libbpf.so.0.0.2
  /usr/local/lib64/libbpf.so.0.0.2

Fixes: 1bf4b058 ("tools: bpftool: add probes for eBPF program types")
Fixes: 1b76c13e ("bpf tools: Introduce 'bpf' library and add bpf feature check")
Reported-by: NStanislav Fomichev <sdf@google.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

Add a small test that shows how to shape a TCP flow in tc-bpf
with EDT and ECN.
Signed-off-by: NPeter Oskolkov <posk@google.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

Make the tests correctly annotate skbs with tunnel metadata.

This makes the gso tests succeed. Enable them.
Signed-off-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

Lower route MTU to ensure packets fit in device MTU after encap, then
skip the gso_size changes.
Signed-off-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

Avoid moving the network layer header when prefixing tunnel headers.

This avoids an explicit call to bpf_skb_store_bytes and an implicit
move of the network header bytes in bpf_skb_adjust_room.
Signed-off-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

Sync include/uapi/linux/bpf.h with tools/

Changes
  v1->v2:
  - BPF_F_ADJ_ROOM_MASK moved, no longer in this commit
  v2->v3:
  - BPF_F_ADJ_ROOM_ENCAP_L3_MASK moved, no longer in this commit
Signed-off-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

Segmentation offload takes a longer path. Verify that the feature
works with large packets.

The test succeeds if not setting dodgy in bpf_skb_adjust_room, as veth
TSO is permissive.

If not setting SKB_GSO_DODGY, this enables tunneled TSO offload on
supporting NICs.

The feature sets SKB_GSO_DODGY because the caller is untrusted. As a
result the packets traverse through the gso stack at least up to TCP.
And fail the gso_type validation, such as the skb->encapsulation check
in gre_gso_segment and the gso_type checks introduced in commit
418e897e ("gso: validate gso_type on ipip style tunnel").

This will be addressed in a follow-on feature patch. In the meantime,
disable the new gso tests.

Changes v1->v2:
  - not all netcat versions support flag '-q', use timeout instead
Signed-off-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

GRE is a commonly used protocol. Add GRE cases for both IPv4 and IPv6.

It also inserts different sized headers, which can expose some
unexpected edge cases.
Signed-off-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

The test only uses ipv4 so far, expand to ipv6.
This is mostly a boilerplate near copy of the ipv4 path.
Signed-off-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

The bpf tunnel test encapsulates using bpf, then decapsulates using
a standard tunnel device to verify correctness.

Once encap is verified, also test decap, by replacing the tunnel
device on decap with another bpf program.
Signed-off-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

Validate basic tunnel encapsulation using ipip.

Set up two namespaces connected by veth. Connect a client and server.
Do this with and without bpf encap.
Signed-off-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

Commit 7640ead9 ("bpf: verifier: make sure callees don't prune
with caller differences") connected up parentage chains of all
frames of the stack.  It didn't, however, ensure propagate_liveness()
propagates all liveness information along those chains.

This means pruning happening in the callee may generate explored
states with incomplete liveness for the chains in lower frames
of the stack.

The included selftest is similar to the prior one from commit
7640ead9 ("bpf: verifier: make sure callees don't prune with
caller differences"), where callee would prune regardless of the
difference in r8 state.

Now we also initialize r9 to 0 or 1 based on a result from get_random().
r9 is never read so the walk with r9 = 0 gets pruned (correctly) after
the walk with r9 = 1 completes.

The selftest is so arranged that the pruning will happen in the
callee.  Since callee does not propagate read marks of r8, the
explored state at the pruning point prior to the callee will
now ignore r8.

Propagate liveness on all frames of the stack when pruning.

Fixes: f4d7e40a ("bpf: introduce function calls (verification)")
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

After some experiences I found that urandom_read does not need to be
linked statically. When the 'read' syscall call is moved to separate
non-inlined function then bpf_get_stackid() is able to find
the executable in stack trace and extract its build_id from it.
Signed-off-by: NIvan Vecera <ivecera@redhat.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

Add tests which verify that the new helpers work for both IPv4 and
IPv6, by forcing SYN cookies to always on. Use a new network namespace
to avoid clobbering the global SYN cookie settings.
Signed-off-by: NLorenz Bauer <lmb@cloudflare.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

Make sure that returning a struct sock_common * reference invokes
the reference tracking machinery in the verifier.
Signed-off-by: NLorenz Bauer <lmb@cloudflare.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

Make the BPF_SK_LOOKUP macro take a helper function, to ease
writing tests for new helpers.
Signed-off-by: NLorenz Bauer <lmb@cloudflare.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

Pull definitions for bpf_skc_lookup_tcp and bpf_sk_check_syncookie.
Signed-off-by: NLorenz Bauer <lmb@cloudflare.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

the following script:

 # tc qdisc add dev crash0 clsact
 # tc filter add dev crash0 egress matchall \
 > action vlan pop pass index 90
 # tc actions replace action vlan \
 > pop goto chain 42 index 90 cookie c1a0c1a0
 # tc actions show action vlan

had the following output:

 Error: Failed to init TC action chain.
 We have an error talking to the kernel
 total acts 1

         action order 0: vlan  pop goto chain 42
          index 90 ref 2 bind 1
         cookie c1a0c1a0

Then, the first packet transmitted by crash0 made the kernel crash:

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
 #PF error: [normal kernel read fault]
 PGD 800000007974f067 P4D 800000007974f067 PUD 79638067 PMD 0
 Oops: 0000 [#1] SMP PTI
 CPU: 3 PID: 0 Comm: swapper/3 Not tainted 5.0.0-rc4.gotochain_crash+ #536
 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
 RIP: 0010:tcf_action_exec+0xb8/0x100
 Code: 00 00 00 20 74 1d 83 f8 03 75 09 49 83 c4 08 4d 39 ec 75 bc 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3 49 8b 97 a8 00 00 00 <48> 8b 12 48 89 55 00 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3
 RSP: 0018:ffff982dfdb83be0 EFLAGS: 00010246
 RAX: 000000002000002a RBX: ffff982dfc55db00 RCX: 0000000000000000
 RDX: 0000000000000000 RSI: ffff982df97099c0 RDI: ffff982dfc55db00
 RBP: ffff982dfdb83c80 R08: ffff982df983fec8 R09: 0000000000000000
 R10: 0000000000000000 R11: 0000000000000000 R12: ffff982df5aacd00
 R13: ffff982df5aacd08 R14: 0000000000000001 R15: ffff982df97099c0
 FS:  0000000000000000(0000) GS:ffff982dfdb80000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000000 CR3: 00000000796d0005 CR4: 00000000001606e0
 Call Trace:
  <IRQ>
  tcf_classify+0x58/0x120
  __dev_queue_xmit+0x40a/0x890
  ? ip6_finish_output2+0x369/0x590
  ip6_finish_output2+0x369/0x590
  ? ip6_output+0x68/0x110
  ip6_output+0x68/0x110
  ? nf_hook.constprop.35+0x79/0xc0
  mld_sendpack+0x16f/0x220
  mld_ifc_timer_expire+0x195/0x2c0
  ? igmp6_timer_handler+0x70/0x70
  call_timer_fn+0x2b/0x130
  run_timer_softirq+0x3e8/0x440
  ? enqueue_hrtimer+0x39/0x90
  __do_softirq+0xe3/0x2f5
  irq_exit+0xf0/0x100
  smp_apic_timer_interrupt+0x6c/0x130
  apic_timer_interrupt+0xf/0x20
  </IRQ>
 RIP: 0010:native_safe_halt+0x2/0x10
 Code: 7b ff ff ff 7f f3 c3 65 48 8b 04 25 00 5c 01 00 f0 80 48 02 20 48 8b 00 a8 08 74 8b eb c1 90 90 90 90 90 90 90 90 90 90 fb f4 <c3> 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 00 f4 c3 90 90 90 90 90 90
 RSP: 0018:ffffa4714038feb8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
 RAX: ffffffff840184f0 RBX: 0000000000000003 RCX: 0000000000000000
 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000001e57d3f387
 RBP: 0000000000000003 R08: 001125d9ca39e1eb R09: 0000000000000000
 R10: 000000000000027d R11: 000000000009f400 R12: 0000000000000000
 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
  ? __sched_text_end+0x1/0x1
  default_idle+0x1c/0x140
  do_idle+0x1c4/0x280
  cpu_startup_entry+0x19/0x20
  start_secondary+0x1a7/0x200
  secondary_startup_64+0xa4/0xb0
 Modules linked in: act_vlan veth ip6table_filter ip6_tables iptable_filter binfmt_misc ext4 snd_hda_codec_generic mbcache crct10dif_pclmul jbd2 snd_hda_intel crc32_pclmul snd_hda_codec ghash_clmulni_intel snd_hwdep snd_hda_core snd_seq snd_seq_device snd_pcm aesni_intel crypto_simd cryptd glue_helper joydev snd_timer virtio_balloon snd pcspkr soundcore i2c_piix4 nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs ata_generic pata_acpi qxl drm_kms_helper syscopyarea sysfillrect sysimgblt virtio_net fb_sys_fops virtio_blk ttm net_failover virtio_console failover ata_piix drm libata crc32c_intel virtio_pci serio_raw virtio_ring virtio floppy dm_mirror dm_region_hash dm_log dm_mod
 CR2: 0000000000000000

Validating the control action within tcf_vlan_init() proved to fix the
above issue. A TDC selftest is added to verify the correct behavior.

Fixes: db50514f ("net: sched: add termination action to allow goto chain")
Fixes: 97763dc0 ("net_sched: reject unknown tcfa_action values")
Signed-off-by: NDavide Caratti <dcaratti@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

the following script:

 # tc qdisc add dev crash0 clsact
 # tc filter add dev crash0 egress matchall \
 > action tunnel_key set src_ip 10.10.10.1 dst_ip 20.20.2 dst_port 3128 \
 > nocsum id 1 pass index 90
 # tc actions replace action tunnel_key \
 > set src_ip 10.10.10.1 dst_ip 20.20.2 dst_port 3128 nocsum id 1 \
 > goto chain 42 index 90 cookie c1a0c1a0
 # tc actions show action tunnel_key

had the following output:

 Error: Failed to init TC action chain.
 We have an error talking to the kernel
 total acts 1

         action order 0: tunnel_key  set
         src_ip 10.10.10.1
         dst_ip 20.20.2.0
         key_id 1
         dst_port 3128
         nocsum goto chain 42
          index 90 ref 2 bind 1
         cookie c1a0c1a0

then, the first packet transmitted by crash0 made the kernel crash:

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
 #PF error: [normal kernel read fault]
 PGD 800000002aba4067 P4D 800000002aba4067 PUD 795f9067 PMD 0
 Oops: 0000 [#1] SMP PTI
 CPU: 3 PID: 0 Comm: swapper/3 Not tainted 5.0.0-rc4.gotochain_crash+ #536
 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
 RIP: 0010:tcf_action_exec+0xb8/0x100
 Code: 00 00 00 20 74 1d 83 f8 03 75 09 49 83 c4 08 4d 39 ec 75 bc 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3 49 8b 97 a8 00 00 00 <48> 8b 12 48 89 55 00 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3
 RSP: 0018:ffff9346bdb83be0 EFLAGS: 00010246
 RAX: 000000002000002a RBX: ffff9346bb795c00 RCX: 0000000000000002
 RDX: 0000000000000000 RSI: ffff93466c881700 RDI: 0000000000000246
 RBP: ffff9346bdb83c80 R08: ffff9346b3e1e0c8 R09: 0000000000000000
 R10: 0000000000000000 R11: 0000000000000000 R12: ffff9346b978f000
 R13: ffff9346b978f008 R14: 0000000000000001 R15: ffff93466dceeb40
 FS:  0000000000000000(0000) GS:ffff9346bdb80000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000000 CR3: 000000007a6c2002 CR4: 00000000001606e0
 Call Trace:
  <IRQ>
  tcf_classify+0x58/0x120
  __dev_queue_xmit+0x40a/0x890
  ? ip6_finish_output2+0x369/0x590
  ip6_finish_output2+0x369/0x590
  ? ip6_output+0x68/0x110
  ip6_output+0x68/0x110
  ? nf_hook.constprop.35+0x79/0xc0
  mld_sendpack+0x16f/0x220
  mld_ifc_timer_expire+0x195/0x2c0
  ? igmp6_timer_handler+0x70/0x70
  call_timer_fn+0x2b/0x130
  run_timer_softirq+0x3e8/0x440
  ? tick_sched_timer+0x37/0x70
  __do_softirq+0xe3/0x2f5
  irq_exit+0xf0/0x100
  smp_apic_timer_interrupt+0x6c/0x130
  apic_timer_interrupt+0xf/0x20
  </IRQ>
 RIP: 0010:native_safe_halt+0x2/0x10
 Code: 55 ff ff ff 7f f3 c3 65 48 8b 04 25 00 5c 01 00 f0 80 48 02 20 48 8b 00 a8 08 74 8b eb c1 90 90 90 90 90 90 90 90 90 90 fb f4 <c3> 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 00 f4 c3 90 90 90 90 90 90
 RSP: 0018:ffffa48a8038feb8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
 RAX: ffffffffaa8184f0 RBX: 0000000000000003 RCX: 0000000000000000
 RDX: 0000000000000001 RSI: 0000000000000087 RDI: 0000000000000003
 RBP: 0000000000000003 R08: 0011251c6fcfac49 R09: ffff9346b995be00
 R10: ffffa48a805e7ce8 R11: 00000000024c38dd R12: 0000000000000000
 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
  ? __sched_text_end+0x1/0x1
  default_idle+0x1c/0x140
  do_idle+0x1c4/0x280
  cpu_startup_entry+0x19/0x20
  start_secondary+0x1a7/0x200
  secondary_startup_64+0xa4/0xb0
 Modules linked in: act_tunnel_key veth ip6table_filter ip6_tables iptable_filter binfmt_misc ext4 crct10dif_pclmul crc32_pclmul snd_hda_codec_generic ghash_clmulni_intel mbcache snd_hda_intel jbd2 snd_hda_codec snd_hwdep snd_hda_core snd_seq snd_seq_device snd_pcm aesni_intel crypto_simd cryptd glue_helper joydev snd_timer snd pcspkr virtio_balloon soundcore i2c_piix4 nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs ata_generic pata_acpi qxl drm_kms_helper syscopyarea sysfillrect virtio_net sysimgblt fb_sys_fops ttm net_failover virtio_console virtio_blk failover drm serio_raw crc32c_intel ata_piix virtio_pci floppy virtio_ring libata virtio dm_mirror dm_region_hash dm_log dm_mod
 CR2: 0000000000000000

Validating the control action within tcf_tunnel_key_init() proved to fix
the above issue. A TDC selftest is added to verify the correct behavior.

Fixes: db50514f ("net: sched: add termination action to allow goto chain")
Fixes: 97763dc0 ("net_sched: reject unknown tcfa_action values")
Signed-off-by: NDavide Caratti <dcaratti@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

the following script:

 # tc qdisc add dev crash0 clsact
 # tc filter add dev crash0 egress matchall \
 > action skbmod set smac 00:c1:a0:c1:a0:00 pass index 90
 # tc actions replace action skbmod \
 > set smac 00:c1:a0:c1:a0:00 goto chain 42 index 90 cookie c1a0c1a0
 # tc actions show action skbmod

had the following output:

 src MAC address <00:c1:a0:c1:a0:00>
 src MAC address <00:c1:a0:c1:a0:00>
 Error: Failed to init TC action chain.
 We have an error talking to the kernel
 total acts 1

         action order 0: skbmod goto chain 42 set smac 00:c1:a0:c1:a0:00
          index 90 ref 2 bind 1
         cookie c1a0c1a0

Then, the first packet transmitted by crash0 made the kernel crash:

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
 #PF error: [normal kernel read fault]
 PGD 800000002d5c7067 P4D 800000002d5c7067 PUD 77e16067 PMD 0
 Oops: 0000 [#1] SMP PTI
 CPU: 3 PID: 0 Comm: swapper/3 Not tainted 5.0.0-rc4.gotochain_crash+ #536
 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
 RIP: 0010:tcf_action_exec+0xb8/0x100
 Code: 00 00 00 20 74 1d 83 f8 03 75 09 49 83 c4 08 4d 39 ec 75 bc 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3 49 8b 97 a8 00 00 00 <48> 8b 12 48 89 55 00 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3
 RSP: 0018:ffff8987ffd83be0 EFLAGS: 00010246
 RAX: 000000002000002a RBX: ffff8987aeb68800 RCX: ffff8987fa263640
 RDX: 0000000000000000 RSI: ffff8987f51c8802 RDI: 00000000000000a0
 RBP: ffff8987ffd83c80 R08: ffff8987f939bac8 R09: 0000000000000000
 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8987f5c77d00
 R13: ffff8987f5c77d08 R14: 0000000000000001 R15: ffff8987f0c29f00
 FS:  0000000000000000(0000) GS:ffff8987ffd80000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000000 CR3: 000000007832c004 CR4: 00000000001606e0
 Call Trace:
  <IRQ>
  tcf_classify+0x58/0x120
  __dev_queue_xmit+0x40a/0x890
  ? ip6_finish_output2+0x369/0x590
  ip6_finish_output2+0x369/0x590
  ? ip6_output+0x68/0x110
  ip6_output+0x68/0x110
  ? nf_hook.constprop.35+0x79/0xc0
  mld_sendpack+0x16f/0x220
  mld_ifc_timer_expire+0x195/0x2c0
  ? igmp6_timer_handler+0x70/0x70
  call_timer_fn+0x2b/0x130
  run_timer_softirq+0x3e8/0x440
  ? tick_sched_timer+0x37/0x70
  __do_softirq+0xe3/0x2f5
  irq_exit+0xf0/0x100
  smp_apic_timer_interrupt+0x6c/0x130
  apic_timer_interrupt+0xf/0x20
  </IRQ>
 RIP: 0010:native_safe_halt+0x2/0x10
 Code: 56 ff ff ff 7f f3 c3 65 48 8b 04 25 00 5c 01 00 f0 80 48 02 20 48 8b 00 a8 08 74 8b eb c1 90 90 90 90 90 90 90 90 90 90 fb f4 <c3> 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 00 f4 c3 90 90 90 90 90 90
 RSP: 0018:ffffa2a1c038feb8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
 RAX: ffffffffa94184f0 RBX: 0000000000000003 RCX: 0000000000000001
 RDX: 0000000000000001 RSI: 0000000000000087 RDI: 0000000000000003
 RBP: 0000000000000003 R08: 001123cfc2ba71ac R09: 0000000000000000
 R10: 0000000000000000 R11: 00000000000f4240 R12: 0000000000000000
 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
  ? __sched_text_end+0x1/0x1
  default_idle+0x1c/0x140
  do_idle+0x1c4/0x280
  cpu_startup_entry+0x19/0x20
  start_secondary+0x1a7/0x200
  secondary_startup_64+0xa4/0xb0
 Modules linked in: act_skbmod veth ip6table_filter ip6_tables iptable_filter binfmt_misc ext4 crct10dif_pclmul crc32_pclmul ghash_clmulni_intel mbcache jbd2 snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core snd_seq snd_seq_device aesni_intel crypto_simd cryptd glue_helper snd_pcm joydev pcspkr virtio_balloon snd_timer snd i2c_piix4 soundcore nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs ata_generic pata_acpi qxl drm_kms_helper syscopyarea sysfillrect virtio_net sysimgblt fb_sys_fops net_failover virtio_console ttm virtio_blk failover drm crc32c_intel serio_raw ata_piix virtio_pci libata virtio_ring virtio floppy dm_mirror dm_region_hash dm_log dm_mod
 CR2: 0000000000000000

Validating the control action within tcf_skbmod_init() proved to fix the
above issue. A TDC selftest is added to verify the correct behavior.

Fixes: db50514f ("net: sched: add termination action to allow goto chain")
Fixes: 97763dc0 ("net_sched: reject unknown tcfa_action values")
Signed-off-by: NDavide Caratti <dcaratti@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

the following script:

 # tc qdisc add dev crash0 clsact
 # tc filter add dev crash0 egress matchall \
 > action skbedit ptype host pass index 90
 # tc actions replace action skbedit \
 > ptype host goto chain 42 index 90 cookie c1a0c1a0
 # tc actions show action skbedit

had the following output:

 Error: Failed to init TC action chain.
 We have an error talking to the kernel
 total acts 1

         action order 0: skbedit  ptype host goto chain 42
          index 90 ref 2 bind 1
         cookie c1a0c1a0

Then, the first packet transmitted by crash0 made the kernel crash:

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
 #PF error: [normal kernel read fault]
 PGD 0 P4D 0
 Oops: 0000 [#1] SMP PTI
 CPU: 3 PID: 3467 Comm: kworker/3:3 Not tainted 5.0.0-rc4.gotochain_crash+ #536
 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
 Workqueue: ipv6_addrconf addrconf_dad_work
 RIP: 0010:tcf_action_exec+0xb8/0x100
 Code: 00 00 00 20 74 1d 83 f8 03 75 09 49 83 c4 08 4d 39 ec 75 bc 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3 49 8b 97 a8 00 00 00 <48> 8b 12 48 89 55 00 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3
 RSP: 0018:ffffb50a81e1fad0 EFLAGS: 00010246
 RAX: 000000002000002a RBX: ffff9aa47ba4ea00 RCX: 0000000000000001
 RDX: 0000000000000000 RSI: ffff9aa469eeb3c0 RDI: ffff9aa47ba4ea00
 RBP: ffffb50a81e1fb70 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000000 R11: ffff9aa47bce0638 R12: ffff9aa4793b0c00
 R13: ffff9aa4793b0c08 R14: 0000000000000001 R15: ffff9aa469eeb3c0
 FS:  0000000000000000(0000) GS:ffff9aa474780000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000000 CR3: 000000007360e005 CR4: 00000000001606e0
 Call Trace:
  tcf_classify+0x58/0x120
  __dev_queue_xmit+0x40a/0x890
  ? ndisc_next_option+0x50/0x50
  ? ___neigh_create+0x4d5/0x680
  ? ip6_finish_output2+0x1b5/0x590
  ip6_finish_output2+0x1b5/0x590
  ? ip6_output+0x68/0x110
  ip6_output+0x68/0x110
  ? nf_hook.constprop.28+0x79/0xc0
  ndisc_send_skb+0x248/0x2e0
  ndisc_send_ns+0xf8/0x200
  ? addrconf_dad_work+0x389/0x4b0
  addrconf_dad_work+0x389/0x4b0
  ? __switch_to_asm+0x34/0x70
  ? process_one_work+0x195/0x380
  ? addrconf_dad_completed+0x370/0x370
  process_one_work+0x195/0x380
  worker_thread+0x30/0x390
  ? process_one_work+0x380/0x380
  kthread+0x113/0x130
  ? kthread_park+0x90/0x90
  ret_from_fork+0x35/0x40
 Modules linked in: act_skbedit veth ip6table_filter ip6_tables iptable_filter binfmt_misc crct10dif_pclmul crc32_pclmul ghash_clmulni_intel ext4 snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hwdep mbcache snd_hda_core jbd2 snd_seq snd_seq_device snd_pcm aesni_intel crypto_simd cryptd snd_timer glue_helper snd joydev soundcore pcspkr virtio_balloon i2c_piix4 nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs ata_generic pata_acpi qxl drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm virtio_net net_failover drm failover virtio_blk virtio_console ata_piix virtio_pci crc32c_intel serio_raw libata virtio_ring virtio floppy dm_mirror dm_region_hash dm_log dm_mod
 CR2: 0000000000000000

Validating the control action within tcf_skbedit_init() proved to fix the
above issue. A TDC selftest is added to verify the correct behavior.

Fixes: db50514f ("net: sched: add termination action to allow goto chain")
Fixes: 97763dc0 ("net_sched: reject unknown tcfa_action values")
Signed-off-by: NDavide Caratti <dcaratti@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

the following script:

 # tc qdisc add dev crash0 clsact
 # tc filter add dev crash0 egress matchall \
 > action simple sdata hello pass index 90
 # tc actions replace action simple \
 > sdata world goto chain 42 index 90 cookie c1a0c1a0
 # tc action show action simple

had the following output:

 Error: Failed to init TC action chain.
 We have an error talking to the kernel
 total acts 1

         action order 0: Simple <world>
          index 90 ref 2 bind 1
         cookie c1a0c1a0

Then, the first packet transmitted by crash0 made the kernel crash:

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
 #PF error: [normal kernel read fault]
 PGD 800000006a6fb067 P4D 800000006a6fb067 PUD 6aed6067 PMD 0
 Oops: 0000 [#1] SMP PTI
 CPU: 2 PID: 3241 Comm: kworker/2:0 Not tainted 5.0.0-rc4.gotochain_crash+ #536
 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
 Workqueue: ipv6_addrconf addrconf_dad_work
 RIP: 0010:tcf_action_exec+0xb8/0x100
 Code: 00 00 00 20 74 1d 83 f8 03 75 09 49 83 c4 08 4d 39 ec 75 bc 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3 49 8b 97 a8 00 00 00 <48> 8b 12 48 89 55 00 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3
 RSP: 0018:ffffbe6781763ad0 EFLAGS: 00010246
 RAX: 000000002000002a RBX: ffff9e59bdb80e00 RCX: 0000000000000000
 RDX: 0000000000000000 RSI: ffff9e59b4716738 RDI: ffff9e59ab12d140
 RBP: ffffbe6781763b70 R08: 0000000000000234 R09: 0000000000aaaaaa
 R10: 0000000000000000 R11: ffff9e59b247cd50 R12: ffff9e59b112f100
 R13: ffff9e59b112f108 R14: 0000000000000001 R15: ffff9e59ab12d0c0
 FS:  0000000000000000(0000) GS:ffff9e59b4700000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000000 CR3: 000000006af92004 CR4: 00000000001606e0
 Call Trace:
  tcf_classify+0x58/0x120
  __dev_queue_xmit+0x40a/0x890
  ? ndisc_next_option+0x50/0x50
  ? ___neigh_create+0x4d5/0x680
  ? ip6_finish_output2+0x1b5/0x590
  ip6_finish_output2+0x1b5/0x590
  ? ip6_output+0x68/0x110
  ip6_output+0x68/0x110
  ? nf_hook.constprop.28+0x79/0xc0
  ndisc_send_skb+0x248/0x2e0
  ndisc_send_ns+0xf8/0x200
  ? addrconf_dad_work+0x389/0x4b0
  addrconf_dad_work+0x389/0x4b0
  ? __switch_to_asm+0x34/0x70
  ? process_one_work+0x195/0x380
  ? addrconf_dad_completed+0x370/0x370
  process_one_work+0x195/0x380
  worker_thread+0x30/0x390
  ? process_one_work+0x380/0x380
  kthread+0x113/0x130
  ? kthread_park+0x90/0x90
  ret_from_fork+0x35/0x40
 Modules linked in: act_simple veth ip6table_filter ip6_tables iptable_filter binfmt_misc crct10dif_pclmul crc32_pclmul ghash_clmulni_intel ext4 snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hwdep mbcache snd_hda_core jbd2 snd_seq snd_seq_device snd_pcm aesni_intel crypto_simd cryptd snd_timer glue_helper snd joydev virtio_balloon pcspkr soundcore i2c_piix4 nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs ata_generic pata_acpi qxl drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops virtio_net ttm net_failover virtio_console virtio_blk failover drm crc32c_intel serio_raw floppy ata_piix libata virtio_pci virtio_ring virtio dm_mirror dm_region_hash dm_log dm_mod
 CR2: 0000000000000000

Validating the control action within tcf_simple_init() proved to fix the
above issue. A TDC selftest is added to verify the correct behavior.

Fixes: db50514f ("net: sched: add termination action to allow goto chain")
Fixes: 97763dc0 ("net_sched: reject unknown tcfa_action values")
Signed-off-by: NDavide Caratti <dcaratti@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

the following script:

 # tc qdisc add dev crash0 clsact
 # tc filter add dev crash0 egress matchall \
 > action sample rate 1024 group 4 pass index 90
 # tc actions replace action sample \
 > rate 1024 group 4 goto chain 42 index 90 cookie c1a0c1a0
 # tc actions show action sample

had the following output:

 Error: Failed to init TC action chain.
 We have an error talking to the kernel
 total acts 1

         action order 0: sample rate 1/1024 group 4 goto chain 42
          index 90 ref 2 bind 1
         cookie c1a0c1a0

Then, the first packet transmitted by crash0 made the kernel crash:

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
 #PF error: [normal kernel read fault]
 PGD 8000000079966067 P4D 8000000079966067 PUD 7987b067 PMD 0
 Oops: 0000 [#1] SMP PTI
 CPU: 0 PID: 5 Comm: kworker/0:0 Not tainted 5.0.0-rc4.gotochain_crash+ #536
 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
 Workqueue: ipv6_addrconf addrconf_dad_work
 RIP: 0010:tcf_action_exec+0xb8/0x100
 Code: 00 00 00 20 74 1d 83 f8 03 75 09 49 83 c4 08 4d 39 ec 75 bc 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3 49 8b 97 a8 00 00 00 <48> 8b 12 48 89 55 00 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3
 RSP: 0018:ffffbee60033fad0 EFLAGS: 00010246
 RAX: 000000002000002a RBX: ffff99d7ae6e3b00 RCX: 00000000e555df9b
 RDX: 0000000000000000 RSI: 00000000b0352718 RDI: ffff99d7fda1fcf0
 RBP: ffffbee60033fb70 R08: 0000000070731ab1 R09: 0000000000000400
 R10: 0000000000000000 R11: ffff99d7ac733838 R12: ffff99d7f3c2be00
 R13: ffff99d7f3c2be08 R14: 0000000000000001 R15: ffff99d7f3c2b600
 FS:  0000000000000000(0000) GS:ffff99d7fda00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000000 CR3: 00000000797de006 CR4: 00000000001606f0
 Call Trace:
  tcf_classify+0x58/0x120
  __dev_queue_xmit+0x40a/0x890
  ? ndisc_next_option+0x50/0x50
  ? ___neigh_create+0x4d5/0x680
  ? ip6_finish_output2+0x1b5/0x590
  ip6_finish_output2+0x1b5/0x590
  ? ip6_output+0x68/0x110
  ip6_output+0x68/0x110
  ? nf_hook.constprop.28+0x79/0xc0
  ndisc_send_skb+0x248/0x2e0
  ndisc_send_ns+0xf8/0x200
  ? addrconf_dad_work+0x389/0x4b0
  addrconf_dad_work+0x389/0x4b0
  ? __switch_to_asm+0x34/0x70
  ? process_one_work+0x195/0x380
  ? addrconf_dad_completed+0x370/0x370
  process_one_work+0x195/0x380
  worker_thread+0x30/0x390
  ? process_one_work+0x380/0x380
  kthread+0x113/0x130
  ? kthread_park+0x90/0x90
  ret_from_fork+0x35/0x40
 Modules linked in: act_sample psample veth ip6table_filter ip6_tables iptable_filter binfmt_misc ext4 crct10dif_pclmul crc32_pclmul ghash_clmulni_intel mbcache jbd2 snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core snd_seq snd_seq_device aesni_intel crypto_simd snd_pcm cryptd glue_helper snd_timer joydev snd pcspkr virtio_balloon i2c_piix4 soundcore nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs ata_generic pata_acpi qxl drm_kms_helper syscopyarea sysfillrect virtio_net sysimgblt fb_sys_fops net_failover ttm failover virtio_blk virtio_console drm ata_piix serio_raw crc32c_intel libata virtio_pci virtio_ring virtio floppy dm_mirror dm_region_hash dm_log dm_mod
 CR2: 0000000000000000

Validating the control action within tcf_sample_init() proved to fix the
above issue. A TDC selftest is added to verify the correct behavior.

Fixes: db50514f ("net: sched: add termination action to allow goto chain")
Fixes: 97763dc0 ("net_sched: reject unknown tcfa_action values")
Signed-off-by: NDavide Caratti <dcaratti@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

the following script:

 # tc qdisc add dev crash0 clsact
 # tc filter add dev crash0 egress matchall \
 > action police rate 3mbit burst 250k pass index 90
 # tc actions replace action police \
 > rate 3mbit burst 250k goto chain 42 index 90 cookie c1a0c1a0
 # tc actions show action police rate 3mbit burst

had the following output:

 Error: Failed to init TC action chain.
 We have an error talking to the kernel
 total acts 1

         action order 0:  police 0x5a rate 3Mbit burst 250Kb mtu 2Kb  action goto chain 42 overhead 0b
         ref 2 bind 1
         cookie c1a0c1a0

Then, when crash0 starts transmitting more than 3Mbit/s, the following
kernel crash is observed:

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
 #PF error: [normal kernel read fault]
 PGD 800000007a779067 P4D 800000007a779067 PUD 2ad96067 PMD 0
 Oops: 0000 [#1] SMP PTI
 CPU: 3 PID: 5032 Comm: netperf Not tainted 5.0.0-rc4.gotochain_crash+ #533
 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
 RIP: 0010:tcf_action_exec+0xb8/0x100
 Code: 00 00 00 20 74 1d 83 f8 03 75 09 49 83 c4 08 4d 39 ec 75 bc 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3 49 8b 97 a8 00 00 00 <48> 8b 12 48 89 55 00 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3
 RSP: 0018:ffffb0e04064fa60 EFLAGS: 00010246
 RAX: 000000002000002a RBX: ffff93bb3322cce0 RCX: 0000000000000005
 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff93bb3322cce0
 RBP: ffffb0e04064fb00 R08: 0000000000000022 R09: 0000000000000000
 R10: 0000000000000000 R11: 0000000000000001 R12: ffff93bb3beed300
 R13: ffff93bb3beed308 R14: 0000000000000001 R15: ffff93bb3b64d000
 FS:  00007f0bc6be5740(0000) GS:ffff93bb3db80000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000000 CR3: 00000000746a8001 CR4: 00000000001606e0
 Call Trace:
  tcf_classify+0x58/0x120
  __dev_queue_xmit+0x40a/0x890
  ? ipt_do_table+0x31c/0x420 [ip_tables]
  ? ip_finish_output2+0x16f/0x430
  ip_finish_output2+0x16f/0x430
  ? ip_output+0x69/0xe0
  ip_output+0x69/0xe0
  ? ip_forward_options+0x1a0/0x1a0
  __tcp_transmit_skb+0x563/0xa40
  tcp_write_xmit+0x243/0xfa0
  __tcp_push_pending_frames+0x32/0xf0
  tcp_sendmsg_locked+0x404/0xd30
  tcp_sendmsg+0x27/0x40
  sock_sendmsg+0x36/0x40
  __sys_sendto+0x10e/0x140
  ? __sys_connect+0x87/0xf0
  ? syscall_trace_enter+0x1df/0x2e0
  ? __audit_syscall_exit+0x216/0x260
  __x64_sys_sendto+0x24/0x30
  do_syscall_64+0x5b/0x180
  entry_SYSCALL_64_after_hwframe+0x44/0xa9
 RIP: 0033:0x7f0bc5ffbafd
 Code: 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 8b 05 ae c4 2c 00 85 c0 75 2d 45 31 c9 45 31 c0 4c 63 d1 48 63 ff b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 63 63 2c 00 f7 d8 64 89 02 48
 RSP: 002b:00007fffef94b7f8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
 RAX: ffffffffffffffda RBX: 0000000000004000 RCX: 00007f0bc5ffbafd
 RDX: 0000000000004000 RSI: 00000000017e5420 RDI: 0000000000000004
 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004
 R13: 00000000017e51d0 R14: 0000000000000010 R15: 0000000000000006
 Modules linked in: act_police veth ip6table_filter ip6_tables iptable_filter binfmt_misc ext4 snd_hda_codec_generic mbcache crct10dif_pclmul jbd2 crc32_pclmul ghash_clmulni_intel snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core snd_seq snd_seq_device snd_pcm aesni_intel crypto_simd cryptd glue_helper snd_timer snd joydev pcspkr virtio_balloon soundcore i2c_piix4 nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs ata_generic pata_acpi qxl drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm virtio_blk virtio_net virtio_console net_failover failover crc32c_intel ata_piix libata serio_raw virtio_pci virtio_ring virtio floppy dm_mirror dm_region_hash dm_log dm_mod
 CR2: 0000000000000000

Validating the control action within tcf_police_init() proved to fix the
above issue. A TDC selftest is added to verify the correct behavior.

Fixes: db50514f ("net: sched: add termination action to allow goto chain")
Fixes: 97763dc0 ("net_sched: reject unknown tcfa_action values")
Signed-off-by: NDavide Caratti <dcaratti@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

the following script:

 # tc filter add dev crash0 egress matchall \
 > action pedit ex munge ip ttl set 10 pass index 90
 # tc actions replace action pedit \
 > ex munge ip ttl set 10 goto chain 42 index 90 cookie c1a0c1a0
 # tc actions show action pedit

had the following output:

 Error: Failed to init TC action chain.
 We have an error talking to the kernel
 total acts 1

         action order 0:  pedit action goto chain 42 keys 1
          index 90 ref 2 bind 1
          key #0  at ipv4+8: val 0a000000 mask 00ffffff
         cookie c1a0c1a0

Then, the first packet transmitted by crash0 made the kernel crash:

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
 #PF error: [normal kernel read fault]
 PGD 0 P4D 0
 Oops: 0000 [#1] SMP PTI
 CPU: 2 PID: 0 Comm: swapper/2 Not tainted 5.0.0-rc4.gotochain_crash+ #533
 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
 RIP: 0010:tcf_action_exec+0xb8/0x100
 Code: 00 00 00 20 74 1d 83 f8 03 75 09 49 83 c4 08 4d 39 ec 75 bc 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3 49 8b 97 a8 00 00 00 <48> 8b 12 48 89 55 00 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3
 RSP: 0018:ffff94a73db03be0 EFLAGS: 00010246
 RAX: 000000002000002a RBX: ffff94a6ee4c0700 RCX: 000000000000000a
 RDX: 0000000000000000 RSI: ffff94a6ed22c800 RDI: 0000000000000000
 RBP: ffff94a73db03c80 R08: ffff94a7386fa4c8 R09: ffff94a73229ea20
 R10: 0000000000000000 R11: 0000000000000000 R12: ffff94a6ed22cb00
 R13: ffff94a6ed22cb08 R14: 0000000000000001 R15: ffff94a6ed22c800
 FS:  0000000000000000(0000) GS:ffff94a73db00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000000 CR3: 000000007120e002 CR4: 00000000001606e0
 Call Trace:
  <IRQ>
  tcf_classify+0x58/0x120
  __dev_queue_xmit+0x40a/0x890
  ? ip6_finish_output2+0x369/0x590
  ip6_finish_output2+0x369/0x590
  ? ip6_output+0x68/0x110
  ip6_output+0x68/0x110
  ? nf_hook.constprop.35+0x79/0xc0
  mld_sendpack+0x16f/0x220
  mld_ifc_timer_expire+0x195/0x2c0
  ? igmp6_timer_handler+0x70/0x70
  call_timer_fn+0x2b/0x130
  run_timer_softirq+0x3e8/0x440
  ? tick_sched_timer+0x37/0x70
  __do_softirq+0xe3/0x2f5
  irq_exit+0xf0/0x100
  smp_apic_timer_interrupt+0x6c/0x130
  apic_timer_interrupt+0xf/0x20
  </IRQ>
 RIP: 0010:native_safe_halt+0x2/0x10
 Code: 4e ff ff ff 7f f3 c3 65 48 8b 04 25 00 5c 01 00 f0 80 48 02 20 48 8b 00 a8 08 74 8b eb c1 90 90 90 90 90 90 90 90 90 90 fb f4 <c3> 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 00 f4 c3 90 90 90 90 90 90
 RSP: 0018:ffffab1740387eb8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
 RAX: ffffffffb18184f0 RBX: 0000000000000002 RCX: 0000000000000001
 RDX: 0000000000000001 RSI: 0000000000000087 RDI: 0000000000000002
 RBP: 0000000000000002 R08: 000f168fa695f9a9 R09: 0000000000000020
 R10: 0000000000000004 R11: 0000000000000000 R12: 0000000000000000
 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
  ? __sched_text_end+0x1/0x1
  default_idle+0x1c/0x140
  do_idle+0x1c4/0x280
  cpu_startup_entry+0x19/0x20
  start_secondary+0x1a7/0x200
  secondary_startup_64+0xa4/0xb0
 Modules linked in: act_pedit veth ip6table_filter ip6_tables iptable_filter binfmt_misc ext4 mbcache jbd2 crct10dif_pclmul crc32_pclmul ghash_clmulni_intel snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hwdep aesni_intel snd_hda_core crypto_simd snd_seq cryptd glue_helper snd_seq_device snd_pcm joydev snd_timer pcspkr virtio_balloon snd soundcore i2c_piix4 nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs qxl ata_generic pata_acpi drm_kms_helper virtio_net net_failover syscopyarea sysfillrect sysimgblt failover virtio_blk fb_sys_fops virtio_console ttm drm crc32c_intel serio_raw ata_piix virtio_pci libata virtio_ring virtio floppy dm_mirror dm_region_hash dm_log dm_mod
 CR2: 0000000000000000

Validating the control action within tcf_pedit_init() proved to fix the
above issue. A TDC selftest is added to verify the correct behavior.

Fixes: db50514f ("net: sched: add termination action to allow goto chain")
Fixes: 97763dc0 ("net_sched: reject unknown tcfa_action values")
Signed-off-by: NDavide Caratti <dcaratti@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

the following script:

 # tc qdisc add dev crash0 clsact
 # tc filter add dev crash0 egress matchall \
 > action nat ingress 1.18.1.1 1.18.2.2 pass index 90
 # tc actions replace action nat \
 > ingress 1.18.1.1 1.18.2.2 goto chain 42 index 90 cookie c1a0c1a0
 # tc actions show action nat

had the following output:

 Error: Failed to init TC action chain.
 We have an error talking to the kernel
 total acts 1

         action order 0:  nat ingress 1.18.1.1/32 1.18.2.2 goto chain 42
          index 90 ref 2 bind 1
         cookie c1a0c1a0

Then, the first packet transmitted by crash0 made the kernel crash:

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
 #PF error: [normal kernel read fault]
 PGD 800000002d180067 P4D 800000002d180067 PUD 7cb8b067 PMD 0
 Oops: 0000 [#1] SMP PTI
 CPU: 3 PID: 164 Comm: kworker/3:1 Not tainted 5.0.0-rc4.gotochain_crash+ #533
 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
 Workqueue: ipv6_addrconf addrconf_dad_work
 RIP: 0010:tcf_action_exec+0xb8/0x100
 Code: 00 00 00 20 74 1d 83 f8 03 75 09 49 83 c4 08 4d 39 ec 75 bc 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3 49 8b 97 a8 00 00 00 <48> 8b 12 48 89 55 00 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3
 RSP: 0018:ffffae4500e2fad0 EFLAGS: 00010246
 RAX: 000000002000002a RBX: ffff9fa52e28c800 RCX: 0000000001011201
 RDX: 0000000000000000 RSI: 0000000000000056 RDI: ffff9fa52ca12800
 RBP: ffffae4500e2fb70 R08: 0000000000000022 R09: 000000000000000e
 R10: 00000000ffffffff R11: 0000000001011201 R12: ffff9fa52cbc9c00
 R13: ffff9fa52cbc9c08 R14: 0000000000000001 R15: ffff9fa52ca12780
 FS:  0000000000000000(0000) GS:ffff9fa57db80000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000000 CR3: 0000000073f8c004 CR4: 00000000001606e0
 Call Trace:
  tcf_classify+0x58/0x120
  __dev_queue_xmit+0x40a/0x890
  ? ndisc_next_option+0x50/0x50
  ? ___neigh_create+0x4d5/0x680
  ? ip6_finish_output2+0x1b5/0x590
  ip6_finish_output2+0x1b5/0x590
  ? ip6_output+0x68/0x110
  ip6_output+0x68/0x110
  ? nf_hook.constprop.28+0x79/0xc0
  ndisc_send_skb+0x248/0x2e0
  ndisc_send_ns+0xf8/0x200
  ? addrconf_dad_work+0x389/0x4b0
  addrconf_dad_work+0x389/0x4b0
  ? __switch_to_asm+0x34/0x70
  ? process_one_work+0x195/0x380
  ? addrconf_dad_completed+0x370/0x370
  process_one_work+0x195/0x380
  worker_thread+0x30/0x390
  ? process_one_work+0x380/0x380
  kthread+0x113/0x130
  ? kthread_park+0x90/0x90
  ret_from_fork+0x35/0x40
 Modules linked in: act_nat veth ip6table_filter ip6_tables iptable_filter binfmt_misc ext4 crct10dif_pclmul crc32_pclmul ghash_clmulni_intel mbcache jbd2 snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core snd_seq snd_seq_device snd_pcm aesni_intel crypto_simd cryptd glue_helper snd_timer snd joydev virtio_balloon pcspkr soundcore i2c_piix4 nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs qxl ata_generic pata_acpi drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm virtio_net virtio_blk net_failover failover virtio_console drm crc32c_intel floppy ata_piix libata virtio_pci virtio_ring virtio serio_raw dm_mirror dm_region_hash dm_log dm_mod
 CR2: 0000000000000000

Validating the control action within tcf_nat_init() proved to fix the
above issue. A TDC selftest is added to verify the correct behavior.

Fixes: db50514f ("net: sched: add termination action to allow goto chain")
Fixes: 97763dc0 ("net_sched: reject unknown tcfa_action values")
Signed-off-by: NDavide Caratti <dcaratti@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

the following script:

 # tc qdisc add dev crash0 clsact
 # tc filter add dev crash0 egress matchall \
 > action connmark pass index 90
 # tc actions replace action connmark \
 > goto chain 42 index 90 cookie c1a0c1a0
 # tc actions show action connmark

had the following output:

 Error: Failed to init TC action chain.
 We have an error talking to the kernel
 total acts 1

         action order 0: connmark zone 0 goto chain 42
          index 90 ref 2 bind 1
         cookie c1a0c1a0

Then, the first packet transmitted by crash0 made the kernel crash:

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
 #PF error: [normal kernel read fault]
 PGD 0 P4D 0
 Oops: 0000 [#1] SMP PTI
 CPU: 0 PID: 302 Comm: kworker/0:2 Not tainted 5.0.0-rc4.gotochain_crash+ #533
 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
 Workqueue: ipv6_addrconf addrconf_dad_work
 RIP: 0010:tcf_action_exec+0xb8/0x100
 Code: 00 00 00 20 74 1d 83 f8 03 75 09 49 83 c4 08 4d 39 ec 75 bc 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3 49 8b 97 a8 00 00 00 <48> 8b 12 48 89 55 00 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3
 RSP: 0018:ffff9bea406c3ad0 EFLAGS: 00010246
 RAX: 000000002000002a RBX: ffff8c5dfc009f00 RCX: 0000000000000000
 RDX: 0000000000000000 RSI: ffff9bea406c3a80 RDI: ffff8c5dfb9d6ec0
 RBP: ffff9bea406c3b70 R08: ffff8c5dfda222a0 R09: ffffffff90933c3c
 R10: 0000000000000000 R11: 0000000092793f7d R12: ffff8c5df48b3c00
 R13: ffff8c5df48b3c08 R14: 0000000000000001 R15: ffff8c5dfb9d6e40
 FS:  0000000000000000(0000) GS:ffff8c5dfda00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000000 CR3: 0000000062e0e006 CR4: 00000000001606f0
 Call Trace:
  tcf_classify+0x58/0x120
  __dev_queue_xmit+0x40a/0x890
  ? ndisc_next_option+0x50/0x50
  ? ___neigh_create+0x4d5/0x680
  ? ip6_finish_output2+0x1b5/0x590
  ip6_finish_output2+0x1b5/0x590
  ? ip6_output+0x68/0x110
  ip6_output+0x68/0x110
  ? nf_hook.constprop.28+0x79/0xc0
  ndisc_send_skb+0x248/0x2e0
  ndisc_send_ns+0xf8/0x200
  ? addrconf_dad_work+0x389/0x4b0
  addrconf_dad_work+0x389/0x4b0
  ? __switch_to_asm+0x34/0x70
  ? process_one_work+0x195/0x380
  ? addrconf_dad_completed+0x370/0x370
  process_one_work+0x195/0x380
  worker_thread+0x30/0x390
  ? process_one_work+0x380/0x380
  kthread+0x113/0x130
  ? kthread_park+0x90/0x90
  ret_from_fork+0x35/0x40
 Modules linked in: act_connmark nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 veth ip6table_filter ip6_tables iptable_filter binfmt_misc ext4 crct10dif_pclmul mbcache crc32_pclmul jbd2 snd_hda_codec_generic ghash_clmulni_intel snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core snd_seq snd_seq_device snd_pcm aesni_intel snd_timer crypto_simd cryptd snd glue_helper joydev virtio_balloon pcspkr soundcore i2c_piix4 nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs ata_generic pata_acpi qxl drm_kms_helper virtio_net net_failover syscopyarea virtio_blk failover virtio_console sysfillrect sysimgblt fb_sys_fops ttm drm ata_piix crc32c_intel serio_raw libata virtio_pci virtio_ring virtio floppy dm_mirror dm_region_hash dm_log dm_mod
 CR2: 0000000000000000

Validating the control action within tcf_connmark_init() proved to fix the
above issue. A TDC selftest is added to verify the correct behavior.

Fixes: db50514f ("net: sched: add termination action to allow goto chain")
Fixes: 97763dc0 ("net_sched: reject unknown tcfa_action values")
Signed-off-by: NDavide Caratti <dcaratti@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

the following script:

 # tc qdisc add dev crash0 clsact
 # tc filter add dev crash0 egress matchall \
 > action mirred ingress mirror dev lo pass
 # tc actions replace action mirred \
 > ingress mirror dev lo goto chain 42 index 90 cookie c1a0c1a0
 # tc actions show action mirred

had the following output:

 Error: Failed to init TC action chain.
 We have an error talking to the kernel
 total acts 1

         action order 0: mirred (Ingress Mirror to device lo) goto chain 42
         index 90 ref 2 bind 1
         cookie c1a0c1a0

Then, the first packet transmitted by crash0 made the kernel crash:

 Mirror/redirect action on
 BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
 #PF error: [normal kernel read fault]
 PGD 0 P4D 0
 Oops: 0000 [#1] SMP PTI
 CPU: 3 PID: 47 Comm: kworker/3:1 Not tainted 5.0.0-rc4.gotochain_crash+ #533
 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
 Workqueue: ipv6_addrconf addrconf_dad_work
 RIP: 0010:tcf_action_exec+0xb8/0x100
 Code: 00 00 00 20 74 1d 83 f8 03 75 09 49 83 c4 08 4d 39 ec 75 bc 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3 49 8b 97 a8 00 00 00 <48> 8b 12 48 89 55 00 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3
 RSP: 0018:ffffa772404b7ad0 EFLAGS: 00010246
 RAX: 000000002000002a RBX: ffff9c5afc3f4300 RCX: 0000000000000000
 RDX: 0000000000000000 RSI: ffff9c5afdba9380 RDI: 0000000000029380
 RBP: ffffa772404b7b70 R08: ffff9c5af7010028 R09: ffff9c5af7010029
 R10: 0000000000000000 R11: ffff9c5af94c6a38 R12: ffff9c5af7953000
 R13: ffff9c5af7953008 R14: 0000000000000001 R15: ffff9c5af7953d00
 FS:  0000000000000000(0000) GS:ffff9c5afdb80000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000000 CR3: 000000007c514004 CR4: 00000000001606e0
 Call Trace:
  tcf_classify+0x58/0x120
  __dev_queue_xmit+0x40a/0x890
  ? ndisc_next_option+0x50/0x50
  ? ___neigh_create+0x4d5/0x680
  ? ip6_finish_output2+0x1b5/0x590
  ip6_finish_output2+0x1b5/0x590
  ? ip6_output+0x68/0x110
  ip6_output+0x68/0x110
  ? nf_hook.constprop.28+0x79/0xc0
  ndisc_send_skb+0x248/0x2e0
  ndisc_send_ns+0xf8/0x200
  ? addrconf_dad_work+0x389/0x4b0
  addrconf_dad_work+0x389/0x4b0
  ? __switch_to_asm+0x34/0x70
  ? process_one_work+0x195/0x380
  ? addrconf_dad_completed+0x370/0x370
  process_one_work+0x195/0x380
  worker_thread+0x30/0x390
  ? process_one_work+0x380/0x380
  kthread+0x113/0x130
  ? kthread_park+0x90/0x90
  ret_from_fork+0x35/0x40
 Modules linked in: act_mirred veth ip6table_filter ip6_tables iptable_filter binfmt_misc ext4 crct10dif_pclmul snd_hda_codec_generic crc32_pclmul snd_hda_intel snd_hda_codec mbcache ghash_clmulni_intel jbd2 snd_hwdep snd_hda_core snd_seq snd_seq_device snd_pcm aesni_intel snd_timer snd crypto_simd cryptd glue_helper soundcore virtio_balloon joydev pcspkr i2c_piix4 nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs ata_generic pata_acpi qxl drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops virtio_net ttm virtio_blk net_failover virtio_console failover drm ata_piix crc32c_intel virtio_pci serio_raw libata virtio_ring virtio floppy dm_mirror dm_region_hash dm_log dm_mod
 CR2: 0000000000000000

Validating the control action within tcf_mirred_init() proved to fix the
above issue. For the same reason, postpone the assignment of tcfa_action
and tcfm_eaction to avoid partial reconfiguration of a mirred rule when
it's replaced by another one that mirrors to a device that does not
exist. A TDC selftest is added to verify the correct behavior.

Fixes: db50514f ("net: sched: add termination action to allow goto chain")
Fixes: 97763dc0 ("net_sched: reject unknown tcfa_action values")
Signed-off-by: NDavide Caratti <dcaratti@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

the following script:

 # tc qdisc add dev crash0 clsact
 # tc filter add dev crash0 egress matchall \
 > action ife encode allow mark pass index 90
 # tc actions replace action ife \
 > encode allow mark goto chain 42 index 90 cookie c1a0c1a0
 # tc action show action ife

had the following output:

 IFE type 0xED3E
 IFE type 0xED3E
 Error: Failed to init TC action chain.
 We have an error talking to the kernel
 total acts 1

         action order 0: ife encode action goto chain 42 type 0XED3E
         allow mark
          index 90 ref 2 bind 1
         cookie c1a0c1a0

Then, the first packet transmitted by crash0 made the kernel crash:

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
 #PF error: [normal kernel read fault]
 PGD 800000007b4e7067 P4D 800000007b4e7067 PUD 7b4e6067 PMD 0
 Oops: 0000 [#1] SMP PTI
 CPU: 2 PID: 164 Comm: kworker/2:1 Not tainted 5.0.0-rc4.gotochain_crash+ #533
 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
 Workqueue: ipv6_addrconf addrconf_dad_work
 RIP: 0010:tcf_action_exec+0xb8/0x100
 Code: 00 00 00 20 74 1d 83 f8 03 75 09 49 83 c4 08 4d 39 ec 75 bc 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3 49 8b 97 a8 00 00 00 <48> 8b 12 48 89 55 00 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3
 RSP: 0018:ffffa6a7c0553ad0 EFLAGS: 00010246
 RAX: 000000002000002a RBX: ffff9796ee1bbd00 RCX: 0000000000000001
 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
 RBP: ffffa6a7c0553b70 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000000 R11: ffff9797385bb038 R12: ffff9796ead9d700
 R13: ffff9796ead9d708 R14: 0000000000000001 R15: ffff9796ead9d800
 FS:  0000000000000000(0000) GS:ffff97973db00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000000 CR3: 000000007c41e006 CR4: 00000000001606e0
 Call Trace:
  tcf_classify+0x58/0x120
  __dev_queue_xmit+0x40a/0x890
  ? ndisc_next_option+0x50/0x50
  ? ___neigh_create+0x4d5/0x680
  ? ip6_finish_output2+0x1b5/0x590
  ip6_finish_output2+0x1b5/0x590
  ? ip6_output+0x68/0x110
  ip6_output+0x68/0x110
  ? nf_hook.constprop.28+0x79/0xc0
  ndisc_send_skb+0x248/0x2e0
  ndisc_send_ns+0xf8/0x200
  ? addrconf_dad_work+0x389/0x4b0
  addrconf_dad_work+0x389/0x4b0
  ? __switch_to_asm+0x34/0x70
  ? process_one_work+0x195/0x380
  ? addrconf_dad_completed+0x370/0x370
  process_one_work+0x195/0x380
  worker_thread+0x30/0x390
  ? process_one_work+0x380/0x380
  kthread+0x113/0x130
  ? kthread_park+0x90/0x90
  ret_from_fork+0x35/0x40
 Modules linked in: act_gact act_meta_mark act_ife dummy veth ip6table_filter ip6_tables iptable_filter binfmt_misc snd_hda_codec_generic ext4 snd_hda_intel snd_hda_codec crct10dif_pclmul mbcache crc32_pclmul jbd2 snd_hwdep snd_hda_core ghash_clmulni_intel snd_seq snd_seq_device snd_pcm snd_timer aesni_intel crypto_simd snd cryptd glue_helper virtio_balloon joydev pcspkr soundcore i2c_piix4 nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs ata_generic pata_acpi qxl virtio_net drm_kms_helper virtio_blk net_failover syscopyarea failover sysfillrect virtio_console sysimgblt fb_sys_fops ttm drm crc32c_intel serio_raw ata_piix virtio_pci virtio_ring libata virtio floppy dm_mirror dm_region_hash dm_log dm_mod [last unloaded: act_ife]
 CR2: 0000000000000000

Validating the control action within tcf_ife_init() proved to fix the
above issue. A TDC selftest is added to verify the correct behavior.

Fixes: db50514f ("net: sched: add termination action to allow goto chain")
Fixes: 97763dc0 ("net_sched: reject unknown tcfa_action values")
Signed-off-by: NDavide Caratti <dcaratti@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

the following script:

 # tc qdisc add dev crash0 clsact
 # tc filter add dev crash0 egress matchall \
 > action gact pass index 90
 # tc actions replace action gact \
 > goto chain 42 index 90 cookie c1a0c1a0
 # tc actions show action gact

had the following output:

 Error: Failed to init TC action chain.
 We have an error talking to the kernel
 total acts 1

         action order 0: gact action goto chain 42
          random type none pass val 0
          index 90 ref 2 bind 1
         cookie c1a0c1a0

Then, the first packet transmitted by crash0 made the kernel crash:

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
 #PF error: [normal kernel read fault]
 PGD 0 P4D 0
 Oops: 0000 [#1] SMP PTI
 CPU: 2 PID: 0 Comm: swapper/2 Not tainted 5.0.0-rc4.gotochain_crash+ #533
 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
 RIP: 0010:tcf_action_exec+0xb8/0x100
 Code: 00 00 00 20 74 1d 83 f8 03 75 09 49 83 c4 08 4d 39 ec 75 bc 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3 49 8b 97 a8 00 00 00 <48> 8b 12 48 89 55 00 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3
 RSP: 0018:ffff8c2434703be0 EFLAGS: 00010246
 RAX: 000000002000002a RBX: ffff8c23ed6d7e00 RCX: 000000000000005a
 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8c23ed6d7e00
 RBP: ffff8c2434703c80 R08: ffff8c243b639ac8 R09: 0000000000000000
 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8c2429e68b00
 R13: ffff8c2429e68b08 R14: 0000000000000001 R15: ffff8c2429c5a480
 FS:  0000000000000000(0000) GS:ffff8c2434700000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000000 CR3: 000000002dc0e005 CR4: 00000000001606e0
 Call Trace:
  <IRQ>
  tcf_classify+0x58/0x120
  __dev_queue_xmit+0x40a/0x890
  ? ip6_finish_output2+0x369/0x590
  ip6_finish_output2+0x369/0x590
  ? ip6_output+0x68/0x110
  ip6_output+0x68/0x110
  ? nf_hook.constprop.35+0x79/0xc0
  mld_sendpack+0x16f/0x220
  mld_ifc_timer_expire+0x195/0x2c0
  ? igmp6_timer_handler+0x70/0x70
  call_timer_fn+0x2b/0x130
  run_timer_softirq+0x3e8/0x440
  ? tick_sched_timer+0x37/0x70
  __do_softirq+0xe3/0x2f5
  irq_exit+0xf0/0x100
  smp_apic_timer_interrupt+0x6c/0x130
  apic_timer_interrupt+0xf/0x20
  </IRQ>
 RIP: 0010:native_safe_halt+0x2/0x10
 Code: 74 ff ff ff 7f f3 c3 65 48 8b 04 25 00 5c 01 00 f0 80 48 02 20 48 8b 00 a8 08 74 8b eb c1 90 90 90 90 90 90 90 90 90 90 fb f4 <c3> 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 00 f4 c3 90 90 90 90 90 90
 RSP: 0018:ffff9c8640387eb8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
 RAX: ffffffff8b2184f0 RBX: 0000000000000002 RCX: 0000000000000001
 RDX: 0000000000000001 RSI: 0000000000000087 RDI: 0000000000000002
 RBP: 0000000000000002 R08: 000eb57882b36cc3 R09: 0000000000000020
 R10: 0000000000000004 R11: 0000000000000000 R12: 0000000000000000
 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
  ? __sched_text_end+0x1/0x1
  default_idle+0x1c/0x140
  do_idle+0x1c4/0x280
  cpu_startup_entry+0x19/0x20
  start_secondary+0x1a7/0x200
  secondary_startup_64+0xa4/0xb0
 Modules linked in: act_gact act_bpf veth ip6table_filter ip6_tables iptable_filter binfmt_misc crct10dif_pclmul crc32_pclmul ghash_clmulni_intel snd_hda_codec_generic ext4 snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core mbcache jbd2 snd_seq snd_seq_device snd_pcm aesni_intel crypto_simd cryptd glue_helper virtio_balloon joydev pcspkr snd_timer snd i2c_piix4 soundcore nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs ata_generic pata_acpi qxl drm_kms_helper syscopyarea virtio_net sysfillrect net_failover virtio_blk sysimgblt fb_sys_fops virtio_console ttm failover drm crc32c_intel serio_raw ata_piix libata floppy virtio_pci virtio_ring virtio dm_mirror dm_region_hash dm_log dm_mod [last unloaded: act_bpf]
 CR2: 0000000000000000

Validating the control action within tcf_gact_init() proved to fix the
above issue. A TDC selftest is added to verify the correct behavior.

Fixes: db50514f ("net: sched: add termination action to allow goto chain")
Fixes: 97763dc0 ("net_sched: reject unknown tcfa_action values")
Signed-off-by: NDavide Caratti <dcaratti@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>