Merge branch 'bpf-sockaddr-wide-store'

Stanislav Fomichev says:

====================
Clang can generate 8-byte stores for user_ip6 & msg_src_ip6,
let's support that on the verifier side.

v3:
* fix comments spelling an -> and (Andrii Nakryiko)

v2:
* Add simple cover letter (Yonghong Song)
* Update comments (Yonghong Song)
* Remove [4] selftests (Yonghong Song)
====================

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

3 files changed, 53 insertions, 6 deletions

diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index cecf42c871d4..e692bb21846f 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -3244,7 +3244,7 @@ struct bpf_sock_addr {
 	__u32 user_ip4;		/* Allows 1,2,4-byte read and 4-byte write.
 				 * Stored in network byte order.
 				 */
-	__u32 user_ip6[4];	/* Allows 1,2,4-byte read an 4-byte write.
+	__u32 user_ip6[4];	/* Allows 1,2,4-byte read and 4,8-byte write.
 				 * Stored in network byte order.
 				 */
 	__u32 user_port;	/* Allows 4-byte read and write.
@@ -3253,10 +3253,10 @@ struct bpf_sock_addr {
 	__u32 family;		/* Allows 4-byte read, but no write */
 	__u32 type;		/* Allows 4-byte read, but no write */
 	__u32 protocol;		/* Allows 4-byte read, but no write */
-	__u32 msg_src_ip4;	/* Allows 1,2,4-byte read an 4-byte write.
+	__u32 msg_src_ip4;	/* Allows 1,2,4-byte read and 4-byte write.
 				 * Stored in network byte order.
 				 */
-	__u32 msg_src_ip6[4];	/* Allows 1,2,4-byte read an 4-byte write.
+	__u32 msg_src_ip6[4];	/* Allows 1,2,4-byte read and 4,8-byte write.
 				 * Stored in network byte order.
 				 */
 	__bpf_md_ptr(struct bpf_sock *, sk);
diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index c5514daf8865..b0773291012a 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -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;
diff --git a/tools/testing/selftests/bpf/verifier/wide_store.c b/tools/testing/selftests/bpf/verifier/wide_store.c
new file mode 100644
index 000000000000..8fe99602ded4
--- /dev/null
+++ b/tools/testing/selftests/bpf/verifier/wide_store.c
@@ -0,0 +1,36 @@
+#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