14 Commits

Author SHA1 Message Date
Wang YanQing
711aef1bbf bpf, x32: Fix bug for BPF_JMP | {BPF_JSGT, BPF_JSLE, BPF_JSLT, BPF_JSGE}
The current method to compare 64-bit numbers for conditional jump is:

1) Compare the high 32-bit first.

2) If the high 32-bit isn't the same, then goto step 4.

3) Compare the low 32-bit.

4) Check the desired condition.

This method is right for unsigned comparison, but it is buggy for signed
comparison, because it does signed comparison for low 32-bit too.

There is only one sign bit in 64-bit number, that is the MSB in the 64-bit
number, it is wrong to treat low 32-bit as signed number and do the signed
comparison for it.

This patch fixes the bug and adds a testcase in selftests/bpf for such bug.

Signed-off-by: Wang YanQing <udknight@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-05-01 23:32:16 +02:00
Paul Chaignon
6dd7f14080 selftests/bpf: test cases for pkt/null checks in subprogs
The first test case, for pointer null checks, is equivalent to the
following pseudo-code.  It checks that the verifier does not complain on
line 6 and recognizes that ptr isn't null.

1: ptr = bpf_map_lookup_elem(map, &key);
2: ret = subprog(ptr) {
3:   return ptr != NULL;
4: }
5: if (ret)
6:   value = *ptr;

The second test case, for packet bound checks, is equivalent to the
following pseudo-code.  It checks that the verifier does not complain on
line 7 and recognizes that the packet is at least 1 byte long.

1: pkt_end = ctx.pkt_end;
2: ptr = ctx.pkt + 8;
3: ret = subprog(ptr, pkt_end) {
4:   return ptr <= pkt_end;
5: }
6: if (ret)
7:   value = *(u8 *)ctx.pkt;

Signed-off-by: Paul Chaignon <paul.chaignon@orange.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-25 17:20:06 -07:00
Paul Chaignon
cabacfbbe5 selftests/bpf: test case for invalid call stack in dead code
This patch adds a test case with an excessive number of call stack frames
in dead code.

Signed-off-by: Paul Chaignon <paul.chaignon@orange.com>
Tested-by: Xiao Han <xiao.han@orange.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-03-26 13:02:16 -07:00
Jakub Kicinski
83d163124c bpf: verifier: propagate liveness on all frames
Commit 7640ead93924 ("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
7640ead93924 ("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: f4d7e40a5b71 ("bpf: introduce function calls (verification)")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-03-21 19:57:02 -07:00
Martin KaFai Lau
b55aa7b04b bpf: Test ref release issue in bpf_tcp_sock and bpf_sk_fullsock
Adding verifier tests to ensure the ptr returned from bpf_tcp_sock() and
bpf_sk_fullsock() cannot be accessed after bpf_sk_release() is called.
A few of the tests are derived from a reproducer test by Lorenz Bauer.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-03-13 12:04:35 -07:00
Daniel Borkmann
20182390c4 bpf: fix replace_map_fd_with_map_ptr's ldimm64 second imm field
Non-zero imm value in the second part of the ldimm64 instruction for
BPF_PSEUDO_MAP_FD is invalid, and thus must be rejected. The map fd
only ever sits in the first instructions' imm field. None of the BPF
loaders known to us are using it, so risk of regression is minimal.
For clarity and consistency, the few insn->{src_reg,imm} occurrences
are rewritten into insn[0].{src_reg,imm}. Add a test case to the BPF
selftest suite as well.

Fixes: 0246e64d9a5f ("bpf: handle pseudo BPF_LD_IMM64 insn")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-03-07 08:47:13 -08:00
Daniel Borkmann
87dab7c3d5 bpf: add test cases for non-pointer sanitiation logic
Add two additional tests for further asserting the
BPF_ALU_NON_POINTER logic with cases that were missed
previously.

Cc: Marek Majkowski <marek@cloudflare.com>
Cc: Arthur Fabre <afabre@cloudflare.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-03-04 10:54:20 +01:00
Martin KaFai Lau
fb47d1d931 bpf: Add skb->sk, bpf_sk_fullsock and bpf_tcp_sock tests to test_verifer
This patch tests accessing the skb->sk and the new helpers,
bpf_sk_fullsock and bpf_tcp_sock.

The errstr of some existing "reference tracking" tests is changed
with s/bpf_sock/sock/ and s/socket/sock/ where "sock" is from the
verifier's reg_type_str[].

Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-02-10 19:46:17 -08:00
Björn Töpel
e2c6f50e48 selftests/bpf: add "any alignment" annotation for some tests
RISC-V does, in-general, not have "efficient unaligned access". When
testing the RISC-V BPF JIT, some selftests failed in the verification
due to misaligned access. Annotate these tests with the
F_NEEDS_EFFICIENT_UNALIGNED_ACCESS flag.

Signed-off-by: Björn Töpel <bjorn.topel@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-02-05 16:56:10 +01:00
Alexei Starovoitov
b4d4556c32 selftests/bpf: add bpf_spin_lock verifier tests
add bpf_spin_lock tests to test_verifier.c that don't require
latest llvm with BTF support

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-02-01 20:55:39 +01:00
Stanislav Fomichev
cfff578ed5 selftests/bpf: mark verifier test that uses bpf_trace_printk as BPF_PROG_TYPE_TRACEPOINT
We don't have this helper if the kernel was compiled without
CONFIG_BPF_EVENTS. Setting prog_type to BPF_PROG_TYPE_TRACEPOINT
let's verifier correctly skip this test based on the missing
prog_type support in the kernel.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-01-31 10:13:21 +01:00
Jakub Kicinski
4872922623 selftests: bpf: break up the rest of test_verifier
Break up the rest of test_verifier tests into separate
files.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-01-27 21:37:45 -08:00
Jakub Kicinski
40f2fbd5a5 selftests: bpf: break up test_verifier
Break up the first 10 kLoC of test verifier test cases
out into smaller files.  Looks like git line counting
gets a little flismy above 16 bit integers, so we need
two commits to break up test_verifier.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-01-27 21:37:45 -08:00
Jakub Kicinski
2dfb40121e selftests: bpf: prepare for break up of verifier tests
test_verifier.c has grown to be very long (almost 16 kLoC),
and it is very conflict prone since we always add tests at
the end.

Try to break it apart a little bit.  Allow test snippets
to be defined in separate files and include them automatically
into the huge test array.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-01-27 21:37:45 -08:00