Commit 46a69aae authored by Leon Hwang's avatar Leon Hwang Committed by Tengda Wu
Browse files

selftests/bpf: Add testcase for updating attached freplace prog to prog_array map 

mainline inclusion
from mainline-v6.12-rc1
commit 7559a7a84ef83a2dd86caf623430b8d834843cec
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBIADD
CVE: CVE-2024-47794

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7559a7a84ef83a2dd86caf623430b8d834843cec



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

Add a selftest to confirm the issue, which gets -EINVAL when update
attached freplace prog to prog_array map, has been fixed.

cd tools/testing/selftests/bpf; ./test_progs -t tailcalls
328/25  tailcalls/tailcall_freplace:OK
328     tailcalls:OK
Summary: 1/25 PASSED, 0 SKIPPED, 0 FAILED

Acked-by: default avatarYonghong Song <yonghong.song@linux.dev>
Signed-off-by: default avatarLeon Hwang <leon.hwang@linux.dev>
Link: https://lore.kernel.org/r/20240728114612.48486-3-leon.hwang@linux.dev


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Conflicts:
	tools/testing/selftests/bpf/prog_tests/tailcalls.c
[The conflict is due to we did not backport b83b936f3e9a testcases]
Signed-off-by: default avatarTengda Wu <wutengda2@huawei.com>
parent db775a8e

tools/testing/selftests/bpf/prog_tests/tailcalls.c

+64 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

#include <test_progs.h>

#include <network_helpers.h>

#include "tailcall_freplace.skel.h"

#include "tc_bpf2bpf.skel.h"



/* test_tailcall_1 checks basic functionality by patching multiple locations

 * in a single program for a single tail call slot with nop->jmp, jmp->nop
@@ -884,6 +886,66 @@ static void test_tailcall_bpf2bpf_6(void) 
	tailcall_bpf2bpf6__destroy(obj);

}



/* test_tailcall_freplace checks that the attached freplace prog is OK to

 * update the prog_array map.

 */

static void test_tailcall_freplace(void)

{

	struct tailcall_freplace *freplace_skel = NULL;

	struct bpf_link *freplace_link = NULL;

	struct bpf_program *freplace_prog;

	struct tc_bpf2bpf *tc_skel = NULL;

	int prog_fd, map_fd;

	char buff[128] = {};

	int err, key;



	LIBBPF_OPTS(bpf_test_run_opts, topts,

		    .data_in = buff,

		    .data_size_in = sizeof(buff),

		    .repeat = 1,

	);



	freplace_skel = tailcall_freplace__open();

	if (!ASSERT_OK_PTR(freplace_skel, "tailcall_freplace__open"))

		return;



	tc_skel = tc_bpf2bpf__open_and_load();

	if (!ASSERT_OK_PTR(tc_skel, "tc_bpf2bpf__open_and_load"))

		goto out;



	prog_fd = bpf_program__fd(tc_skel->progs.entry_tc);

	freplace_prog = freplace_skel->progs.entry_freplace;

	err = bpf_program__set_attach_target(freplace_prog, prog_fd, "subprog");

	if (!ASSERT_OK(err, "set_attach_target"))

		goto out;



	err = tailcall_freplace__load(freplace_skel);

	if (!ASSERT_OK(err, "tailcall_freplace__load"))

		goto out;



	freplace_link = bpf_program__attach_freplace(freplace_prog, prog_fd,

						     "subprog");

	if (!ASSERT_OK_PTR(freplace_link, "attach_freplace"))

		goto out;



	map_fd = bpf_map__fd(freplace_skel->maps.jmp_table);

	prog_fd = bpf_program__fd(freplace_prog);

	key = 0;

	err = bpf_map_update_elem(map_fd, &key, &prog_fd, BPF_ANY);

	if (!ASSERT_OK(err, "update jmp_table"))

		goto out;



	prog_fd = bpf_program__fd(tc_skel->progs.entry_tc);

	err = bpf_prog_test_run_opts(prog_fd, &topts);

	ASSERT_OK(err, "test_run");

	ASSERT_EQ(topts.retval, 34, "test_run retval");



out:

	bpf_link__destroy(freplace_link);

	tc_bpf2bpf__destroy(tc_skel);

	tailcall_freplace__destroy(freplace_skel);

}



void test_tailcalls(void)

{

	if (test__start_subtest("tailcall_1"))
@@ -910,4 +972,6 @@ void test_tailcalls(void) 
		test_tailcall_bpf2bpf_4(true);

	if (test__start_subtest("tailcall_bpf2bpf_6"))

		test_tailcall_bpf2bpf_6();

	if (test__start_subtest("tailcall_freplace"))

		test_tailcall_freplace();

}

tools/testing/selftests/bpf/progs/tailcall_freplace.c

0 → 100644
+23 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0



#include <linux/bpf.h>

#include <bpf/bpf_helpers.h>



struct {

	__uint(type, BPF_MAP_TYPE_PROG_ARRAY);

	__uint(max_entries, 1);

	__uint(key_size, sizeof(__u32));

	__uint(value_size, sizeof(__u32));

} jmp_table SEC(".maps");



int count = 0;



SEC("freplace")

int entry_freplace(struct __sk_buff *skb)

{

	count++;

	bpf_tail_call_static(skb, &jmp_table, 0);

	return count;

}



char __license[] SEC("license") = "GPL";

tools/testing/selftests/bpf/progs/tc_bpf2bpf.c

0 → 100644
+22 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0



#include <linux/bpf.h>

#include <bpf/bpf_helpers.h>

#include "bpf_misc.h"



__noinline

int subprog(struct __sk_buff *skb)

{

	int ret = 1;



	__sink(ret);

	return ret;

}



SEC("tc")

int entry_tc(struct __sk_buff *skb)

{

	return subprog(skb);

}



char __license[] SEC("license") = "GPL";