Add a new type flag for bpf_arg_type that when set tells verifier that
for a release function, that argument's register will be the one for
which meta.ref_obj_id will be set, and which will then be released
using release_reference. To capture the regno, introduce a new field
release_regno in bpf_call_arg_meta.
This would be required in the next patch, where we may either pass NULL
or a refcounted pointer as an argument to the release function
bpf_kptr_xchg. Just releasing only when meta.ref_obj_id is set is not
enough, as there is a case where the type of argument needed matches,
but the ref_obj_id is set to 0. Hence, we must enforce that whenever
meta.ref_obj_id is zero, the register that is to be released can only
be NULL for a release function.
Since we now indicate whether an argument is to be released in
bpf_func_proto itself, is_release_function helper has lost its utitlity,
hence refactor code to work without it, and just rely on
meta.release_regno to know when to release state for a ref_obj_id.
Still, the restriction of one release argument and only one ref_obj_id
passed to BPF helper or kfunc remains. This may be lifted in the future.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220424214901.2743946-3-memxor@gmail.com
In particular these include:
1) Remove output of inv for scalars in print_verifier_state
2) Replace inv with scalar in verifier error messages
3) Remove _value suffixes for umin/umax/s32_min/etc (except map_value)
4) Remove output of id=0
5) Remove output of ref_obj_id=0
Signed-off-by: Mykola Lysenko <mykolal@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220301222745.1667206-1-mykolal@fb.com
Add coverage to the verifier tests and tests for reading bpf_sock fields to
ensure that 32-bit, 16-bit, and 8-bit loads from dst_port field are allowed
only at intended offsets and produce expected values.
While 16-bit and 8-bit access to dst_port field is straight-forward, 32-bit
wide loads need be allowed and produce a zero-padded 16-bit value for
backward compatibility.
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/r/20220130115518.213259-3-jakub@cloudflare.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch tests:
int bpf_cls(struct __sk_buff *skb)
{
/* REG_6: sk
* REG_7: tp
* REG_8: req_sk
*/
sk = skb->sk;
if (!sk)
return 0;
tp = bpf_skc_to_tcp_sock(sk);
req_sk = bpf_skc_to_tcp_request_sock(sk);
if (!req_sk)
return 0;
/* !tp has not been tested, so verifier should reject. */
return *(__u8 *)tp;
}
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201019194219.1051314-1-kafai@fb.com
Adjust verifier test due to addition of new field.
Fixes: c3c16f2ea6 ("bpf: Add rx_queue_mapping to bpf_sock")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Check that verifier allows passing a map of type:
BPF_MAP_TYPE_REUSEPORT_SOCKARRARY, or
BPF_MAP_TYPE_SOCKMAP, or
BPF_MAP_TYPE_SOCKHASH
... to bpf_sk_select_reuseport helper.
Suggested-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200430104738.494180-1-jakub@cloudflare.com
Now that bpf_map_lookup_elem() is white-listed for SOCKMAP/SOCKHASH,
replace the tests which check that verifier prevents lookup on these map
types with ones that ensure that lookup operation is permitted, but only
with a release of acquired socket reference.
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200429181154.479310-3-jakub@cloudflare.com
Check that bpf_map_lookup_elem lookup and structure
access operats correctly.
Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch adds verifier tests for the bpf_sk_storage:
1. ARG_PTR_TO_MAP_VALUE_OR_NULL
2. Map and helper compatibility (e.g. disallow bpf_map_loookup_elem)
It also takes this chance to remove the unused struct btf_raw_data
and uses the BTF encoding macros from "test_btf.h".
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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>
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>