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<title>user/sven/linux.git/kernel/bpf, branch v5.7.17</title>
<subtitle>Linux Kernel
</subtitle>
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<updated>2020-08-11T13:35:34Z</updated>
<entry>
<title>bpf: Fix NULL pointer dereference in __btf_resolve_helper_id()</title>
<updated>2020-08-11T13:35:34Z</updated>
<author>
<name>Peilin Ye</name>
<email>yepeilin.cs@gmail.com</email>
</author>
<published>2020-07-14T18:09:04Z</published>
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<id>urn:sha1:06b46481d51fac58bb776067478ceeb460339a57</id>
<content type='text'>
[ Upstream commit 5b801dfb7feb2738975d80223efc2fc193e55573 ]

Prevent __btf_resolve_helper_id() from dereferencing `btf_vmlinux`
as NULL. This patch fixes the following syzbot bug:

    https://syzkaller.appspot.com/bug?id=f823224ada908fa5c207902a5a62065e53ca0fcc

Reported-by: syzbot+ee09bda7017345f1fbe6@syzkaller.appspotmail.com
Signed-off-by: Peilin Ye &lt;yepeilin.cs@gmail.com&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Link: https://lore.kernel.org/bpf/20200714180904.277512-1-yepeilin.cs@gmail.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>bpf: Fix map leak in HASH_OF_MAPS map</title>
<updated>2020-08-05T07:58:45Z</updated>
<author>
<name>Andrii Nakryiko</name>
<email>andriin@fb.com</email>
</author>
<published>2020-07-29T04:09:12Z</published>
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<id>urn:sha1:82547aa3a8da8b672dd6c26a70d09d32d9bb6296</id>
<content type='text'>
[ Upstream commit 1d4e1eab456e1ee92a94987499b211db05f900ea ]

Fix HASH_OF_MAPS bug of not putting inner map pointer on bpf_map_elem_update()
operation. This is due to per-cpu extra_elems optimization, which bypassed
free_htab_elem() logic doing proper clean ups. Make sure that inner map is put
properly in optimized case as well.

Fixes: 8c290e60fa2a ("bpf: fix hashmap extra_elems logic")
Signed-off-by: Andrii Nakryiko &lt;andriin@fb.com&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Acked-by: Song Liu &lt;songliubraving@fb.com&gt;
Link: https://lore.kernel.org/bpf/20200729040913.2815687-1-andriin@fb.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>bpf: Set the number of exception entries properly for subprograms</title>
<updated>2020-07-29T08:19:35Z</updated>
<author>
<name>Yonghong Song</name>
<email>yhs@fb.com</email>
</author>
<published>2020-06-24T00:10:54Z</published>
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[ Upstream commit c4c0bdc0d2d084ed847c7066bdf59fe2cd25aa17 ]

Currently, if a bpf program has more than one subprograms, each program will be
jitted separately. For programs with bpf-to-bpf calls the
prog-&gt;aux-&gt;num_exentries is not setup properly. For example, with
bpf_iter_netlink.c modified to force one function to be not inlined and with
CONFIG_BPF_JIT_ALWAYS_ON the following error is seen:
   $ ./test_progs -n 3/3
   ...
   libbpf: failed to load program 'iter/netlink'
   libbpf: failed to load object 'bpf_iter_netlink'
   libbpf: failed to load BPF skeleton 'bpf_iter_netlink': -4007
   test_netlink:FAIL:bpf_iter_netlink__open_and_load skeleton open_and_load failed
   #3/3 netlink:FAIL
The dmesg shows the following errors:
   ex gen bug
which is triggered by the following code in arch/x86/net/bpf_jit_comp.c:
   if (excnt &gt;= bpf_prog-&gt;aux-&gt;num_exentries) {
     pr_err("ex gen bug\n");
     return -EFAULT;
   }

This patch fixes the issue by computing proper num_exentries for each
subprogram before calling JIT.

Signed-off-by: Yonghong Song &lt;yhs@fb.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>bpf: sockmap: Require attach_bpf_fd when detaching a program</title>
<updated>2020-07-22T07:34:29Z</updated>
<author>
<name>Lorenz Bauer</name>
<email>lmb@cloudflare.com</email>
</author>
<published>2020-06-29T09:56:28Z</published>
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commit bb0de3131f4c60a9bf976681e0fe4d1e55c7a821 upstream.

The sockmap code currently ignores the value of attach_bpf_fd when
detaching a program. This is contrary to the usual behaviour of
checking that attach_bpf_fd represents the currently attached
program.

Ensure that attach_bpf_fd is indeed the currently attached
program. It turns out that all sockmap selftests already do this,
which indicates that this is unlikely to cause breakage.

Fixes: 604326b41a6f ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: Lorenz Bauer &lt;lmb@cloudflare.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20200629095630.7933-5-lmb@cloudflare.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>bpf: Check correct cred for CAP_SYSLOG in bpf_dump_raw_ok()</title>
<updated>2020-07-16T06:13:30Z</updated>
<author>
<name>Kees Cook</name>
<email>keescook@chromium.org</email>
</author>
<published>2020-07-02T22:45:23Z</published>
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<id>urn:sha1:3a2cfe930439ee41b9f4d77453c00592a54f9e1a</id>
<content type='text'>
commit 63960260457a02af2a6cb35d75e6bdb17299c882 upstream.

When evaluating access control over kallsyms visibility, credentials at
open() time need to be used, not the "current" creds (though in BPF's
case, this has likely always been the same). Plumb access to associated
file-&gt;f_cred down through bpf_dump_raw_ok() and its callers now that
kallsysm_show_value() has been refactored to take struct cred.

Cc: Alexei Starovoitov &lt;ast@kernel.org&gt;
Cc: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Cc: bpf@vger.kernel.org
Cc: stable@vger.kernel.org
Fixes: 7105e828c087 ("bpf: allow for correlation of maps and helpers in dump")
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>bpf: Do not allow btf_ctx_access with __int128 types</title>
<updated>2020-07-16T06:13:18Z</updated>
<author>
<name>John Fastabend</name>
<email>john.fastabend@gmail.com</email>
</author>
<published>2020-06-24T22:20:39Z</published>
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<id>urn:sha1:82d1d58e9f2070b0055f29480ab43b629cb280ef</id>
<content type='text'>
[ Upstream commit a9b59159d338d414acaa8e2f569d129d51c76452 ]

To ensure btf_ctx_access() is safe the verifier checks that the BTF
arg type is an int, enum, or pointer. When the function does the
BTF arg lookup it uses the calculation 'arg = off / 8'  using the
fact that registers are 8B. This requires that the first arg is
in the first reg, the second in the second, and so on. However,
for __int128 the arg will consume two registers by default LLVM
implementation. So this will cause the arg layout assumed by the
'arg = off / 8' calculation to be incorrect.

Because __int128 is uncommon this patch applies the easiest fix and
will force int types to be sizeof(u64) or smaller so that they will
fit in a single register.

v2: remove unneeded parens per Andrii's feedback

Fixes: 9e15db66136a1 ("bpf: Implement accurate raw_tp context access via BTF")
Signed-off-by: John Fastabend &lt;john.fastabend@gmail.com&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Acked-by: Andrii Nakryiko &lt;andriin@fb.com&gt;
Link: https://lore.kernel.org/bpf/159303723962.11287.13309537171132420717.stgit@john-Precision-5820-Tower
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>bpf: Don't return EINVAL from {get,set}sockopt when optlen &gt; PAGE_SIZE</title>
<updated>2020-06-30T19:36:04Z</updated>
<author>
<name>Stanislav Fomichev</name>
<email>sdf@google.com</email>
</author>
<published>2020-06-17T01:04:14Z</published>
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<id>urn:sha1:fb63225de50476ad5d928cb3a69c303724d29901</id>
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[ Upstream commit d8fe449a9c51a37d844ab607e14e2f5c657d3cf2 ]

Attaching to these hooks can break iptables because its optval is
usually quite big, or at least bigger than the current PAGE_SIZE limit.
David also mentioned some SCTP options can be big (around 256k).

For such optvals we expose only the first PAGE_SIZE bytes to
the BPF program. BPF program has two options:
1. Set ctx-&gt;optlen to 0 to indicate that the BPF's optval
   should be ignored and the kernel should use original userspace
   value.
2. Set ctx-&gt;optlen to something that's smaller than the PAGE_SIZE.

v5:
* use ctx-&gt;optlen == 0 with trimmed buffer (Alexei Starovoitov)
* update the docs accordingly

v4:
* use temporary buffer to avoid optval == optval_end == NULL;
  this removes the corner case in the verifier that might assume
  non-zero PTR_TO_PACKET/PTR_TO_PACKET_END.

v3:
* don't increase the limit, bypass the argument

v2:
* proper comments formatting (Jakub Kicinski)

Fixes: 0d01da6afc54 ("bpf: implement getsockopt and setsockopt hooks")
Signed-off-by: Stanislav Fomichev &lt;sdf@google.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Cc: David Laight &lt;David.Laight@ACULAB.COM&gt;
Link: https://lore.kernel.org/bpf/20200617010416.93086-1-sdf@google.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>devmap: Use bpf_map_area_alloc() for allocating hash buckets</title>
<updated>2020-06-30T19:36:04Z</updated>
<author>
<name>Toke Høiland-Jørgensen</name>
<email>toke@redhat.com</email>
</author>
<published>2020-06-16T14:28:29Z</published>
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<id>urn:sha1:cc2dd9e108f3f7a3bad4d0872d24992f56d8c074</id>
<content type='text'>
[ Upstream commit 99c51064fb06146b3d494b745c947e438a10aaa7 ]

Syzkaller discovered that creating a hash of type devmap_hash with a large
number of entries can hit the memory allocator limit for allocating
contiguous memory regions. There's really no reason to use kmalloc_array()
directly in the devmap code, so just switch it to the existing
bpf_map_area_alloc() function that is used elsewhere.

Fixes: 6f9d451ab1a3 ("xdp: Add devmap_hash map type for looking up devices by hashed index")
Reported-by: Xiumei Mu &lt;xmu@redhat.com&gt;
Signed-off-by: Toke Høiland-Jørgensen &lt;toke@redhat.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Acked-by: John Fastabend &lt;john.fastabend@gmail.com&gt;
Link: https://lore.kernel.org/bpf/20200616142829.114173-1-toke@redhat.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>bpf: Undo internal BPF_PROBE_MEM in BPF insns dump</title>
<updated>2020-06-24T15:49:12Z</updated>
<author>
<name>Andrii Nakryiko</name>
<email>andriin@fb.com</email>
</author>
<published>2020-06-13T00:21:15Z</published>
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<id>urn:sha1:bd12abafd9c173e3ee4a6179ae940d106987acf8</id>
<content type='text'>
[ Upstream commit 29fcb05bbf1a7008900bb9bee347bdbfc7171036 ]

BPF_PROBE_MEM is kernel-internal implmementation details. When dumping BPF
instructions to user-space, it needs to be replaced back with BPF_MEM mode.

Fixes: 2a02759ef5f8 ("bpf: Add support for BTF pointers to interpreter")
Signed-off-by: Andrii Nakryiko &lt;andriin@fb.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20200613002115.1632142-1-andriin@fb.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>bpf: Fix an error code in check_btf_func()</title>
<updated>2020-06-24T15:49:04Z</updated>
<author>
<name>Dan Carpenter</name>
<email>dan.carpenter@oracle.com</email>
</author>
<published>2020-06-04T08:54:36Z</published>
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[ Upstream commit e7ed83d6fa1a00d0f2ad0327e73d3ea9e7ea8de1 ]

This code returns success if the "info_aux" allocation fails but it
should return -ENOMEM.

Fixes: 8c1b6e69dcc1 ("bpf: Compare BTF types of functions arguments with actual types")
Signed-off-by: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Acked-by: Song Liu &lt;songliubraving@fb.com&gt;
Link: https://lore.kernel.org/bpf/20200604085436.GA943001@mwanda
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
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