Commit 76d95077 authored by Stanislav Fomichev's avatar Stanislav Fomichev Committed by Daniel Borkmann
Browse files

selftests/bpf: add verifier tests for wide stores 



Make sure that wide stores are allowed at proper (aligned) addresses.
Note that user_ip6 is naturally aligned on 8-byte boundary, so
correct addresses are user_ip6[0] and user_ip6[2]. msg_src_ip6 is,
however, aligned on a 4-byte bondary, so only msg_src_ip6[1]
can be wide-stored.

Cc: Andrii Nakryiko <andriin@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Acked-by: default avatarAndrii Nakryiko <andriin@fb.com>
Signed-off-by: default avatarStanislav Fomichev <sdf@google.com>
Acked-by: default avatarYonghong Song <yhs@fb.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parent 4cfacbe6

tools/testing/selftests/bpf/test_verifier.c

+14 −3
Original line number Diff line number Diff line
@@ -105,6 +105,7 @@ struct bpf_test { 
			__u64 data64[TEST_DATA_LEN / 8];

		};

	} retvals[MAX_TEST_RUNS];

	enum bpf_attach_type expected_attach_type;

};



/* Note we want this to be 64 bit aligned so that the end of our array is
@@ -850,6 +851,7 @@ static void do_test_single(struct bpf_test *test, bool unpriv, 
	int fd_prog, expected_ret, alignment_prevented_execution;

	int prog_len, prog_type = test->prog_type;

	struct bpf_insn *prog = test->insns;

	struct bpf_load_program_attr attr;

	int run_errs, run_successes;

	int map_fds[MAX_NR_MAPS];

	const char *expected_err;
@@ -881,8 +883,17 @@ static void do_test_single(struct bpf_test *test, bool unpriv, 
		pflags |= BPF_F_STRICT_ALIGNMENT;

	if (test->flags & F_NEEDS_EFFICIENT_UNALIGNED_ACCESS)

		pflags |= BPF_F_ANY_ALIGNMENT;

	fd_prog = bpf_verify_program(prog_type, prog, prog_len, pflags,

				     "GPL", 0, bpf_vlog, sizeof(bpf_vlog), 4);



	memset(&attr, 0, sizeof(attr));

	attr.prog_type = prog_type;

	attr.expected_attach_type = test->expected_attach_type;

	attr.insns = prog;

	attr.insns_cnt = prog_len;

	attr.license = "GPL";

	attr.log_level = 4;

	attr.prog_flags = pflags;



	fd_prog = bpf_load_program_xattr(&attr, bpf_vlog, sizeof(bpf_vlog));

	if (fd_prog < 0 && !bpf_probe_prog_type(prog_type, 0)) {

		printf("SKIP (unsupported program type %d)\n", prog_type);

		skips++;
@@ -912,7 +923,7 @@ static void do_test_single(struct bpf_test *test, bool unpriv, 
			printf("FAIL\nUnexpected success to load!\n");

			goto fail_log;

		}

		if (!strstr(bpf_vlog, expected_err)) {

		if (!expected_err || !strstr(bpf_vlog, expected_err)) {

			printf("FAIL\nUnexpected error message!\n\tEXP: %s\n\tRES: %s\n",

			      expected_err, bpf_vlog);

			goto fail_log;

tools/testing/selftests/bpf/verifier/wide_store.c

0 → 100644
+36 −0
Original line number Diff line number Diff line 
#define BPF_SOCK_ADDR(field, off, res, err) \

{ \

	"wide store to bpf_sock_addr." #field "[" #off "]", \

	.insns = { \

	BPF_MOV64_IMM(BPF_REG_0, 1), \

	BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, \

		    offsetof(struct bpf_sock_addr, field[off])), \

	BPF_EXIT_INSN(), \

	}, \

	.result = res, \

	.prog_type = BPF_PROG_TYPE_CGROUP_SOCK_ADDR, \

	.expected_attach_type = BPF_CGROUP_UDP6_SENDMSG, \

	.errstr = err, \

}



/* user_ip6[0] is u64 aligned */

BPF_SOCK_ADDR(user_ip6, 0, ACCEPT,

	      NULL),

BPF_SOCK_ADDR(user_ip6, 1, REJECT,

	      "invalid bpf_context access off=12 size=8"),

BPF_SOCK_ADDR(user_ip6, 2, ACCEPT,

	      NULL),

BPF_SOCK_ADDR(user_ip6, 3, REJECT,

	      "invalid bpf_context access off=20 size=8"),



/* msg_src_ip6[0] is _not_ u64 aligned */

BPF_SOCK_ADDR(msg_src_ip6, 0, REJECT,

	      "invalid bpf_context access off=44 size=8"),

BPF_SOCK_ADDR(msg_src_ip6, 1, ACCEPT,

	      NULL),

BPF_SOCK_ADDR(msg_src_ip6, 2, REJECT,

	      "invalid bpf_context access off=52 size=8"),

BPF_SOCK_ADDR(msg_src_ip6, 3, REJECT,

	      "invalid bpf_context access off=56 size=8"),



#undef BPF_SOCK_ADDR

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