bpf: Fix ringbuf helper function compatibility

mainline inclusion
from mainline-5.10.62
commit 9dd6f6d89693d8f09af53d2488afad22a8a44a57
bugzilla: 182217 https://gitee.com/openeuler/kernel/issues/I4EFOS

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=9dd6f6d89693d8f09af53d2488afad22a8a44a57

--------------------------------

commit 5b029a32 upstream.

Commit 457f4436 ("bpf: Implement BPF ring buffer and verifier support
for it") extended check_map_func_compatibility() by enforcing map -> helper
function match, but not helper -> map type match.

Due to this all of the bpf_ringbuf_*() helper functions could be used with
a wrong map type such as array or hash map, leading to invalid access due
to type confusion.

Also, both BPF_FUNC_ringbuf_{submit,discard} have ARG_PTR_TO_ALLOC_MEM as
argument and not a BPF map. Therefore, their check_map_func_compatibility()
presence is incorrect since it's only for map type checking.

Fixes: 457f4436 ("bpf: Implement BPF ring buffer and verifier support for it")
Reported-by: Ryota Shiga (Flatt Security)
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

kernel/bpf/verifier.c

@@ -4693,8 +4693,6 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env,
 	case BPF_MAP_TYPE_RINGBUF:
 		if (func_id != BPF_FUNC_ringbuf_output &&
 		    func_id != BPF_FUNC_ringbuf_reserve &&
-		    func_id != BPF_FUNC_ringbuf_submit &&
-		    func_id != BPF_FUNC_ringbuf_discard &&
 		    func_id != BPF_FUNC_ringbuf_query)
 			goto error;
 		break;
@@ -4798,6 +4796,12 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env,
 		if (map->map_type != BPF_MAP_TYPE_PERF_EVENT_ARRAY)
 			goto error;
 		break;
+	case BPF_FUNC_ringbuf_output:
+	case BPF_FUNC_ringbuf_reserve:
+	case BPF_FUNC_ringbuf_query:
+		if (map->map_type != BPF_MAP_TYPE_RINGBUF)
+			goto error;
+		break;
 	case BPF_FUNC_get_stackid:
 		if (map->map_type != BPF_MAP_TYPE_STACK_TRACE)
 			goto error;