Commit 4991277d authored by Xu Kuohai's avatar Xu Kuohai Committed by Pu Lehui
Browse files

selftests/bpf: Add test for lsm tail call 

mainline inclusion
from mainline-v6.12-rc1
commit d463dd9c9aa24b17ccb8ed76bdd7768baf857b48
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAYRIC
CVE: CVE-2024-50063

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d463dd9c9aa2



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

Add test for lsm tail call to ensure tail call can only be used between
bpf lsm progs attached to the same hook.

Signed-off-by: default avatarXu Kuohai <xukuohai@huawei.com>
Link: https://lore.kernel.org/r/20240719110059.797546-9-xukuohai@huaweicloud.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Conflicts:
	tools/testing/selftests/bpf/prog_tests/test_lsm.c
[Adapt for some minor issue]
Signed-off-by: default avatarPu Lehui <pulehui@huawei.com>
parent b05a820d

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

+45 −1
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
#include <unistd.h>



#include "lsm.skel.h"

#include "lsm_tailcall.skel.h"



char *CMD_ARGS[] = {"true", NULL};
@@ -52,7 +53,7 @@ int exec_cmd(int *monitored_pid) 
	return -EINVAL;

}



void test_test_lsm(void)

static void test_lsm_basic(void)

{

	struct lsm *skel = NULL;

	int err, duration = 0;
@@ -93,3 +94,46 @@ void test_test_lsm(void) 
close_prog:

	lsm__destroy(skel);

}



static void test_lsm_tailcall(void)

{

	struct lsm_tailcall *skel = NULL;

	int map_fd, prog_fd;

	int err, key;



	skel = lsm_tailcall__open_and_load();

	if (!ASSERT_OK_PTR(skel, "lsm_tailcall__skel_load"))

		goto close_prog;



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

	if (CHECK_FAIL(map_fd < 0))

		goto close_prog;



	prog_fd = bpf_program__fd(skel->progs.lsm_file_permission_prog);

	if (CHECK_FAIL(prog_fd < 0))

		goto close_prog;



	key = 0;

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

	if (CHECK_FAIL(!err))

		goto close_prog;



	prog_fd = bpf_program__fd(skel->progs.lsm_file_alloc_security_prog);

	if (CHECK_FAIL(prog_fd < 0))

		goto close_prog;



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

	if (CHECK_FAIL(err))

		goto close_prog;



close_prog:

	lsm_tailcall__destroy(skel);

}



void test_test_lsm(void)

{

	if (test__start_subtest("lsm_basic"))

		test_lsm_basic();

	if (test__start_subtest("lsm_tailcall"))

		test_lsm_tailcall();

}

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

0 → 100644
+34 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/* Copyright (c) 2024 Huawei Technologies Co., Ltd */



#include "vmlinux.h"

#include <errno.h>

#include <bpf/bpf_helpers.h>



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



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");



SEC("lsm/file_permission")

int lsm_file_permission_prog(void *ctx)

{

	return 0;

}



SEC("lsm/file_alloc_security")

int lsm_file_alloc_security_prog(void *ctx)

{

	return 0;

}



SEC("lsm/file_alloc_security")

int lsm_file_alloc_security_entry(void *ctx)

{

	bpf_tail_call_static(ctx, &jmp_table, 0);

	return 0;

}