<feed xmlns='http://www.w3.org/2005/Atom'>
<title>BMC/Intel-BMC/linux.git/tools/testing/selftests/bpf, branch dev-5.4</title>
<subtitle>Intel OpenBMC Linux kernel source tree (mirror)</subtitle>
<id>https://git.radix-linux.su/BMC/Intel-BMC/linux.git/atom?h=dev-5.4</id>
<link rel='self' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/atom?h=dev-5.4'/>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/'/>
<updated>2020-08-07T07:34:02+00:00</updated>
<entry>
<title>selftests: bpf: Fix detach from sockmap tests</title>
<updated>2020-08-07T07:34:02+00:00</updated>
<author>
<name>Lorenz Bauer</name>
<email>lmb@cloudflare.com</email>
</author>
<published>2020-07-09T11:51:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=9fe975acb53fa4c35bd8fd9c1ec6a47056659b46'/>
<id>urn:sha1:9fe975acb53fa4c35bd8fd9c1ec6a47056659b46</id>
<content type='text'>
commit f43cb0d672aa8eb09bfdb779de5900c040487d1d upstream.

Fix sockmap tests which rely on old bpf_prog_dispatch behaviour.
In the first case, the tests check that detaching without giving
a program succeeds. Since these are not the desired semantics,
invert the condition. In the second case, the clean up code doesn't
supply the necessary program fds.

Fixes: bb0de3131f4c ("bpf: sockmap: Require attach_bpf_fd when detaching a program")
Reported-by: Martin KaFai Lau &lt;kafai@fb.com&gt;
Signed-off-by: Lorenz Bauer &lt;lmb@cloudflare.com&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Reviewed-by: Jakub Sitnicki &lt;jakub@cloudflare.com&gt;
Link: https://lore.kernel.org/bpf/20200709115151.75829-1-lmb@cloudflare.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>selftests/bpf, flow_dissector: Close TAP device FD after the test</title>
<updated>2020-06-22T07:31:12+00:00</updated>
<author>
<name>Jakub Sitnicki</name>
<email>jakub@cloudflare.com</email>
</author>
<published>2020-05-31T08:28:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=c48a842d8ce7a12997c569ce3be7d439b4fa5843'/>
<id>urn:sha1:c48a842d8ce7a12997c569ce3be7d439b4fa5843</id>
<content type='text'>
[ Upstream commit b8215dce7dfd817ca38807f55165bf502146cd68 ]

test_flow_dissector leaves a TAP device after it's finished, potentially
interfering with other tests that will run after it. Fix it by closing the
TAP descriptor on cleanup.

Fixes: 0905beec9f52 ("selftests/bpf: run flow dissector tests in skb-less mode")
Signed-off-by: Jakub Sitnicki &lt;jakub@cloudflare.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20200531082846.2117903-11-jakub@cloudflare.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>selftests/bpf: CONFIG_IPV6_SEG6_BPF required for test_seg6_loop.o</title>
<updated>2020-06-22T07:31:08+00:00</updated>
<author>
<name>Alan Maguire</name>
<email>alan.maguire@oracle.com</email>
</author>
<published>2020-05-22T11:36:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=41b44325c9eb05c788079c12619d62f0136a5252'/>
<id>urn:sha1:41b44325c9eb05c788079c12619d62f0136a5252</id>
<content type='text'>
[ Upstream commit 3c8e8cf4b18b3a7034fab4c4504fc4b54e4b6195 ]

test_seg6_loop.o uses the helper bpf_lwt_seg6_adjust_srh();
it will not be present if CONFIG_IPV6_SEG6_BPF is not specified.

Fixes: b061017f8b4d ("selftests/bpf: add realistic loop tests")
Signed-off-by: Alan Maguire &lt;alan.maguire@oracle.com&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Link: https://lore.kernel.org/bpf/1590147389-26482-2-git-send-email-alan.maguire@oracle.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>selftests/bpf: Fix memory leak in extract_build_id()</title>
<updated>2020-06-22T07:31:00+00:00</updated>
<author>
<name>Andrii Nakryiko</name>
<email>andriin@fb.com</email>
</author>
<published>2020-04-29T01:21:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=1dbb13ceedac8200ba452cf896c6114ce4b84e08'/>
<id>urn:sha1:1dbb13ceedac8200ba452cf896c6114ce4b84e08</id>
<content type='text'>
[ Upstream commit 9f56bb531a809ecaa7f0ddca61d2cf3adc1cb81a ]

getline() allocates string, which has to be freed.

Fixes: 81f77fd0deeb ("bpf: add selftest for stackmap with BPF_F_STACK_BUILD_ID")
Signed-off-by: Andrii Nakryiko &lt;andriin@fb.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Cc: Song Liu &lt;songliubraving@fb.com&gt;
Link: https://lore.kernel.org/bpf/20200429012111.277390-7-andriin@fb.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>bpf: Test_progs, fix test_get_stack_rawtp_err.c build</title>
<updated>2020-05-20T06:20:41+00:00</updated>
<author>
<name>Kamal Mostafa</name>
<email>kamal@canonical.com</email>
</author>
<published>2020-04-28T17:21:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=ecb3f529a554fcd5b58afde1fe69be771f41901a'/>
<id>urn:sha1:ecb3f529a554fcd5b58afde1fe69be771f41901a</id>
<content type='text'>
The linux-5.4.y commit 8781011a302b ("bpf: Test_progs, add test to catch
retval refine error handling") fails to build when libbpf headers are
not installed, as it tries to include &lt;bpf/bpf_helpers.h&gt;:

  progs/test_get_stack_rawtp_err.c:4:10:
      fatal error: 'bpf/bpf_helpers.h' file not found

For 5.4-stable (only) the new test prog needs to include "bpf_helpers.h"
instead (like all the rest of progs/*.c do) because 5.4-stable does not
carry commit e01a75c15969 ("libbpf: Move bpf_{helpers, helper_defs,
endian, tracing}.h into libbpf").

Signed-off-by: Kamal Mostafa &lt;kamal@canonical.com&gt;
Fixes: 8781011a302b ("bpf: Test_progs, add test to catch retval refine error handling")
Cc: &lt;stable@vger.kernel.org&gt; # v5.4
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>selftest/bpf: fix backported test_select_reuseport selftest changes</title>
<updated>2020-05-20T06:20:40+00:00</updated>
<author>
<name>Andrii Nakryiko</name>
<email>andriin@fb.com</email>
</author>
<published>2020-05-16T00:40:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=aee43146cc103483f87c072c74833204676fb893'/>
<id>urn:sha1:aee43146cc103483f87c072c74833204676fb893</id>
<content type='text'>
Fix up RET_IF as CHECK macro to make selftests compile again.

Fixes: b911c5e8686a ("selftests: bpf: Reset global state between reuseport test runs")
Signed-off-by: Andrii Nakryiko &lt;andriin@fb.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>selftests/bpf: fix goto cleanup label not defined</title>
<updated>2020-05-20T06:20:07+00:00</updated>
<author>
<name>Hangbin Liu</name>
<email>liuhangbin@gmail.com</email>
</author>
<published>2020-05-15T03:38:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=a761f65879e80b43e27195c7af998684fb47e64d'/>
<id>urn:sha1:a761f65879e80b43e27195c7af998684fb47e64d</id>
<content type='text'>
kernel test robot found a warning when build bpf selftest for 5.4.y stable
tree:

prog_tests/stacktrace_build_id_nmi.c:55:3: error: label ‘cleanup’ used but not defined
   goto cleanup;
   ^~~~

This is because we are lacking upstream commit dde53c1b763b
("selftests/bpf: Convert few more selftest to skeletons"). But this
commit is too large and need more backports. To fix it, the
easiest way is just use the current goto label 'close_prog'.

Reported-by: kernel test robot &lt;rong.a.chen@intel.com&gt;
Fixes: da43712a7262 ("selftests/bpf: Skip perf hw events test if the setup disabled it")
Signed-off-by: Hangbin Liu &lt;liuhangbin@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>bpf: Forbid XADD on spilled pointers for unprivileged users</title>
<updated>2020-05-02T06:48:46+00:00</updated>
<author>
<name>Jann Horn</name>
<email>jannh@google.com</email>
</author>
<published>2020-04-17T00:00:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=db2426f86d44fc423aa36fd8b8302aa7155e161f'/>
<id>urn:sha1:db2426f86d44fc423aa36fd8b8302aa7155e161f</id>
<content type='text'>
commit 6e7e63cbb023976d828cdb22422606bf77baa8a9 upstream.

When check_xadd() verifies an XADD operation on a pointer to a stack slot
containing a spilled pointer, check_stack_read() verifies that the read,
which is part of XADD, is valid. However, since the placeholder value -1 is
passed as `value_regno`, check_stack_read() can only return a binary
decision and can't return the type of the value that was read. The intent
here is to verify whether the value read from the stack slot may be used as
a SCALAR_VALUE; but since check_stack_read() doesn't check the type, and
the type information is lost when check_stack_read() returns, this is not
enforced, and a malicious user can abuse XADD to leak spilled kernel
pointers.

Fix it by letting check_stack_read() verify that the value is usable as a
SCALAR_VALUE if no type information is passed to the caller.

To be able to use __is_pointer_value() in check_stack_read(), move it up.

Fix up the expected unprivileged error message for a BPF selftest that,
until now, assumed that unprivileged users can use XADD on stack-spilled
pointers. This also gives us a test for the behavior introduced in this
patch for free.

In theory, this could also be fixed by forbidding XADD on stack spills
entirely, since XADD is a locked operation (for operations on memory with
concurrency) and there can't be any concurrency on the BPF stack; but
Alexei has said that he wants to keep XADD on stack slots working to avoid
changes to the test suite [1].

The following BPF program demonstrates how to leak a BPF map pointer as an
unprivileged user using this bug:

    // r7 = map_pointer
    BPF_LD_MAP_FD(BPF_REG_7, small_map),
    // r8 = launder(map_pointer)
    BPF_STX_MEM(BPF_DW, BPF_REG_FP, BPF_REG_7, -8),
    BPF_MOV64_IMM(BPF_REG_1, 0),
    ((struct bpf_insn) {
      .code  = BPF_STX | BPF_DW | BPF_XADD,
      .dst_reg = BPF_REG_FP,
      .src_reg = BPF_REG_1,
      .off = -8
    }),
    BPF_LDX_MEM(BPF_DW, BPF_REG_8, BPF_REG_FP, -8),

    // store r8 into map
    BPF_MOV64_REG(BPF_REG_ARG1, BPF_REG_7),
    BPF_MOV64_REG(BPF_REG_ARG2, BPF_REG_FP),
    BPF_ALU64_IMM(BPF_ADD, BPF_REG_ARG2, -4),
    BPF_ST_MEM(BPF_W, BPF_REG_ARG2, 0, 0),
    BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
    BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
    BPF_EXIT_INSN(),
    BPF_STX_MEM(BPF_DW, BPF_REG_0, BPF_REG_8, 0),

    BPF_MOV64_IMM(BPF_REG_0, 0),
    BPF_EXIT_INSN()

[1] https://lore.kernel.org/bpf/20200416211116.qxqcza5vo2ddnkdq@ast-mbp.dhcp.thefacebook.com/

Fixes: 17a5267067f3 ("bpf: verifier (add verifier core)")
Signed-off-by: Jann Horn &lt;jannh@google.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20200417000007.10734-1-jannh@google.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>bpf, test_verifier: switch bpf_get_stack's 0 s&gt; r8 test</title>
<updated>2020-04-23T08:36:46+00:00</updated>
<author>
<name>Daniel Borkmann</name>
<email>daniel@iogearbox.net</email>
</author>
<published>2020-04-21T13:01:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=a801a05ca7145fd2b72dad35bd01977014241e55'/>
<id>urn:sha1:a801a05ca7145fd2b72dad35bd01977014241e55</id>
<content type='text'>
[ no upstream commit ]

Switch the comparison, so that is_branch_taken() will recognize that below
branch is never taken:

  [...]
  17: [...] R1_w=inv0 [...] R8_w=inv(id=0,smin_value=-2147483648,smax_value=-1,umin_value=18446744071562067968,var_off=(0xffffffff80000000; 0x7fffffff)) [...]
  17: (67) r8 &lt;&lt;= 32
  18: [...] R8_w=inv(id=0,smax_value=-4294967296,umin_value=9223372036854775808,umax_value=18446744069414584320,var_off=(0x8000000000000000; 0x7fffffff00000000)) [...]
  18: (c7) r8 s&gt;&gt;= 32
  19: [...] R8_w=inv(id=0,smin_value=-2147483648,smax_value=-1,umin_value=18446744071562067968,var_off=(0xffffffff80000000; 0x7fffffff)) [...]
  19: (6d) if r1 s&gt; r8 goto pc+16
  [...] R1_w=inv0 [...] R8_w=inv(id=0,smin_value=-2147483648,smax_value=-1,umin_value=18446744071562067968,var_off=(0xffffffff80000000; 0x7fffffff)) [...]
  [...]

Currently we check for is_branch_taken() only if either K is source, or source
is a scalar value that is const. For upstream it would be good to extend this
properly to check whether dst is const and src not.

For the sake of the test_verifier, it is probably not needed here:

  # ./test_verifier 101
  #101/p bpf_get_stack return R0 within range OK
  Summary: 1 PASSED, 0 SKIPPED, 0 FAILED

I haven't seen this issue in test_progs* though, they are passing fine:

  # ./test_progs-no_alu32 -t get_stack
  Switching to flavor 'no_alu32' subdirectory...
  #20 get_stack_raw_tp:OK
  Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED

  # ./test_progs -t get_stack
  #20 get_stack_raw_tp:OK
  Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Acked-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Acked-by: John Fastabend &lt;john.fastabend@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>bpf: Test_progs, add test to catch retval refine error handling</title>
<updated>2020-04-23T08:36:46+00:00</updated>
<author>
<name>John Fastabend</name>
<email>john.fastabend@gmail.com</email>
</author>
<published>2020-03-30T21:37:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=8781011a302bac86d92a930e9a8c0fdf3f1df697'/>
<id>urn:sha1:8781011a302bac86d92a930e9a8c0fdf3f1df697</id>
<content type='text'>
commit d2db08c7a14e0b5eed6132baf258b80622e041a9 upstream.

Before this series the verifier would clamp return bounds of
bpf_get_stack() to [0, X] and this led the verifier to believe
that a JMP_JSLT 0 would be false and so would prune that path.

The result is anything hidden behind that JSLT would be unverified.
Add a test to catch this case by hiding an goto pc-1 behind the
check which will cause an infinite loop if not rejected.

Signed-off-by: John Fastabend &lt;john.fastabend@gmail.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Link: https://lore.kernel.org/bpf/158560423908.10843.11783152347709008373.stgit@john-Precision-5820-Tower
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
</feed>
