<feed xmlns='http://www.w3.org/2005/Atom'>
<title>BMC/Intel-BMC/linux.git/tools/testing/selftests/bpf/test_verifier.c, branch master</title>
<subtitle>Intel OpenBMC Linux kernel source tree (mirror)</subtitle>
<id>https://git.radix-linux.su/BMC/Intel-BMC/linux.git/atom?h=master</id>
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<updated>2017-08-04T23:09:06+00:00</updated>
<entry>
<title>bpf: fix byte order test in test_verifier</title>
<updated>2017-08-04T23:09:06+00:00</updated>
<author>
<name>Daniel Borkmann</name>
<email>daniel@iogearbox.net</email>
</author>
<published>2017-08-04T20:24:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=2c460621bb2e6baf8a475c407cdb29029b2497ac'/>
<id>urn:sha1:2c460621bb2e6baf8a475c407cdb29029b2497ac</id>
<content type='text'>
We really must check with #if __BYTE_ORDER == XYZ instead of
just presence of #ifdef __LITTLE_ENDIAN. I noticed that when
actually running this on big endian machine, the latter test
resolves to true for user space, same for #ifdef __BIG_ENDIAN.

E.g., looking at endian.h from libc, both are also defined
there, so we really must test this against __BYTE_ORDER instead
for proper insns selection. For the kernel, such checks are
fine though e.g. see 13da9e200fe4 ("Revert "endian: #define
__BYTE_ORDER"") and 415586c9e6d3 ("UAPI: fix endianness conditionals
in M32R's asm/stat.h") for some more context, but not for
user space. Lets also make sure to properly include endian.h.
After that, suite passes for me:

./test_verifier: ELF 64-bit MSB executable, [...]

Linux foo 4.13.0-rc3+ #4 SMP Fri Aug 4 06:59:30 EDT 2017 s390x s390x s390x GNU/Linux

Before fix: Summary: 505 PASSED, 11 FAILED
After  fix: Summary: 516 PASSED,  0 FAILED

Fixes: 18f3d6be6be1 ("selftests/bpf: Add test cases to test narrower ctx field loads")
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Acked-by: Yonghong &lt;yhs@fb.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>selftests/bpf: subtraction bounds test</title>
<updated>2017-07-24T21:02:55+00:00</updated>
<author>
<name>Edward Cree</name>
<email>ecree@solarflare.com</email>
</author>
<published>2017-07-21T13:36:57+00:00</published>
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<id>urn:sha1:545722cb0fc993226a01844fb27cf832459eb1c0</id>
<content type='text'>
There is a bug in the verifier's handling of BPF_SUB: [a,b] - [c,d] yields
 was [a-c, b-d] rather than the correct [a-d, b-c].  So here is a test
 which, with the bogus handling, will produce ranges of [0,0] and thus
 allowed accesses; whereas the correct handling will give a range of
 [-255, 255] (and hence the right-shift will give a range of [0, 255]) and
 the accesses will be rejected.

Signed-off-by: Edward Cree &lt;ecree@solarflare.com&gt;
Acked-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>bpf: more tests for mixed signed and unsigned bounds checks</title>
<updated>2017-07-20T22:20:27+00:00</updated>
<author>
<name>Daniel Borkmann</name>
<email>daniel@iogearbox.net</email>
</author>
<published>2017-07-20T22:00:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=8641250251bfcd93479c71783c6792ae3325d7e4'/>
<id>urn:sha1:8641250251bfcd93479c71783c6792ae3325d7e4</id>
<content type='text'>
Add a couple of more test cases to BPF selftests that are related
to mixed signed and unsigned checks.

Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Acked-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>bpf: add test for mixed signed and unsigned bounds checks</title>
<updated>2017-07-20T22:20:27+00:00</updated>
<author>
<name>Edward Cree</name>
<email>ecree@solarflare.com</email>
</author>
<published>2017-07-20T22:00:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=b712296a41ce0a114895fdff68fc22aada165b07'/>
<id>urn:sha1:b712296a41ce0a114895fdff68fc22aada165b07</id>
<content type='text'>
These failed due to a bug in verifier bounds handling.

Signed-off-by: Edward Cree &lt;ecree@solarflare.com&gt;
Acked-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Acked-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>bpf: fix up test cases with mixed signed/unsigned bounds</title>
<updated>2017-07-20T22:20:27+00:00</updated>
<author>
<name>Daniel Borkmann</name>
<email>daniel@iogearbox.net</email>
</author>
<published>2017-07-20T22:00:23+00:00</published>
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<id>urn:sha1:a1502132866fd2d2705eef4041dd6d7d849f48a2</id>
<content type='text'>
Fix the few existing test cases that used mixed signed/unsigned
bounds and switch them only to one flavor. Reason why we need this
is that proper boundaries cannot be derived from mixed tests.

Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Acked-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>bpf: allow to specify log level and reduce it for test_verifier</title>
<updated>2017-07-20T22:20:27+00:00</updated>
<author>
<name>Daniel Borkmann</name>
<email>daniel@iogearbox.net</email>
</author>
<published>2017-07-20T22:00:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=d655490417ee22da3267fe6592a0ec2023c3c0db'/>
<id>urn:sha1:d655490417ee22da3267fe6592a0ec2023c3c0db</id>
<content type='text'>
For the test_verifier case, it's quite hard to parse log level 2 to
figure out what's causing an issue when used to log level 1. We do
want to use bpf_verify_program() in order to simulate some of the
tests with strict alignment. So just add an argument to pass the level
and put it to 1 for test_verifier.

Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Acked-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>bpf: add various test cases for verifier selftest</title>
<updated>2017-07-03T09:22:52+00:00</updated>
<author>
<name>Daniel Borkmann</name>
<email>daniel@iogearbox.net</email>
</author>
<published>2017-07-02T00:13:31+00:00</published>
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<id>urn:sha1:6d191ed40d8d84ef0045cd44c75c63770e250f2d</id>
<content type='text'>
Add couple of verifier test cases for x|imm += pkt_ptr, including the
imm += x extension.

Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Acked-by: John Fastabend &lt;john.fastabend@gmail.com&gt;
Acked-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net</title>
<updated>2017-06-30T16:43:08+00:00</updated>
<author>
<name>David S. Miller</name>
<email>davem@davemloft.net</email>
</author>
<published>2017-06-30T16:43:08+00:00</published>
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<id>urn:sha1:b07911593719828cac023bdcf6bf4da1c9ba546f</id>
<content type='text'>
A set of overlapping changes in macvlan and the rocker
driver, nothing serious.

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>bpf: prevent leaking pointer via xadd on unpriviledged</title>
<updated>2017-06-29T19:44:34+00:00</updated>
<author>
<name>Daniel Borkmann</name>
<email>daniel@iogearbox.net</email>
</author>
<published>2017-06-29T01:04:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=6bdf6abc56b53103324dfd270a86580306e1a232'/>
<id>urn:sha1:6bdf6abc56b53103324dfd270a86580306e1a232</id>
<content type='text'>
Leaking kernel addresses on unpriviledged is generally disallowed,
for example, verifier rejects the following:

  0: (b7) r0 = 0
  1: (18) r2 = 0xffff897e82304400
  3: (7b) *(u64 *)(r1 +48) = r2
  R2 leaks addr into ctx

Doing pointer arithmetic on them is also forbidden, so that they
don't turn into unknown value and then get leaked out. However,
there's xadd as a special case, where we don't check the src reg
for being a pointer register, e.g. the following will pass:

  0: (b7) r0 = 0
  1: (7b) *(u64 *)(r1 +48) = r0
  2: (18) r2 = 0xffff897e82304400 ; map
  4: (db) lock *(u64 *)(r1 +48) += r2
  5: (95) exit

We could store the pointer into skb-&gt;cb, loose the type context,
and then read it out from there again to leak it eventually out
of a map value. Or more easily in a different variant, too:

   0: (bf) r6 = r1
   1: (7a) *(u64 *)(r10 -8) = 0
   2: (bf) r2 = r10
   3: (07) r2 += -8
   4: (18) r1 = 0x0
   6: (85) call bpf_map_lookup_elem#1
   7: (15) if r0 == 0x0 goto pc+3
   R0=map_value(ks=8,vs=8,id=0),min_value=0,max_value=0 R6=ctx R10=fp
   8: (b7) r3 = 0
   9: (7b) *(u64 *)(r0 +0) = r3
  10: (db) lock *(u64 *)(r0 +0) += r6
  11: (b7) r0 = 0
  12: (95) exit

  from 7 to 11: R0=inv,min_value=0,max_value=0 R6=ctx R10=fp
  11: (b7) r0 = 0
  12: (95) exit

Prevent this by checking xadd src reg for pointer types. Also
add a couple of test cases related to this.

Fixes: 1be7f75d1668 ("bpf: enable non-root eBPF programs")
Fixes: 17a5267067f3 ("bpf: verifier (add verifier core)")
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Acked-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Acked-by: Martin KaFai Lau &lt;kafai@fb.com&gt;
Acked-by: Edward Cree &lt;ecree@solarflare.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>selftests/bpf: Add test cases to test narrower ctx field loads</title>
<updated>2017-06-14T18:56:25+00:00</updated>
<author>
<name>Yonghong Song</name>
<email>yhs@fb.com</email>
</author>
<published>2017-06-13T22:52:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=18f3d6be6be124316d3abfee667c5e8b88dec100'/>
<id>urn:sha1:18f3d6be6be124316d3abfee667c5e8b88dec100</id>
<content type='text'>
Add test cases in test_verifier and test_progs.
Negative tests are added in test_verifier as well.
The test in test_progs will compare the value of narrower ctx field
load result vs. the masked value of normal full-field load result,
and will fail if they are not the same.

Acked-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Signed-off-by: Yonghong Song &lt;yhs@fb.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
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