selftests/bpf: Add test cases for inner map
Add test cases to test the race between the destroy of inner map due to map-in-map update and the access of inner map in bpf program. The following 4 combinations are added: (1) array map in map array + bpf program (2) array map in map array + sleepable bpf program (3) array map in map htab + bpf program (4) array map in map htab + sleepable bpf program Before applying the fixes, when running `./test_prog -a map_in_map`, the following error was reported: ================================================================== BUG: KASAN: slab-use-after-free in array_map_update_elem+0x48/0x3e0 Read of size 4 at addr ffff888114f33824 by task test_progs/1858 CPU: 1 PID: 1858 Comm: test_progs Tainted: G O 6.6.0+ #7 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) ...... Call Trace: <TASK> dump_stack_lvl+0x4a/0x90 print_report+0xd2/0x620 kasan_report+0xd1/0x110 __asan_load4+0x81/0xa0 array_map_update_elem+0x48/0x3e0 bpf_prog_be94a9f26772f5b7_access_map_in_array+0xe6/0xf6 trace_call_bpf+0x1aa/0x580 kprobe_perf_func+0xdd/0x430 kprobe_dispatcher+0xa0/0xb0 kprobe_ftrace_handler+0x18b/0x2e0 0xffffffffc02280f7 RIP: 0010:__x64_sys_getpgid+0x1/0x30 ...... </TASK> Allocated by task 1857: kasan_save_stack+0x26/0x50 kasan_set_track+0x25/0x40 kasan_save_alloc_info+0x1e/0x30 __kasan_kmalloc+0x98/0xa0 __kmalloc_node+0x6a/0x150 __bpf_map_area_alloc+0x141/0x170 bpf_map_area_alloc+0x10/0x20 array_map_alloc+0x11f/0x310 map_create+0x28a/0xb40 __sys_bpf+0x753/0x37c0 __x64_sys_bpf+0x44/0x60 do_syscall_64+0x36/0xb0 entry_SYSCALL_64_after_hwframe+0x6e/0x76 Freed by task 11: kasan_save_stack+0x26/0x50 kasan_set_track+0x25/0x40 kasan_save_free_info+0x2b/0x50 __kasan_slab_free+0x113/0x190 slab_free_freelist_hook+0xd7/0x1e0 __kmem_cache_free+0x170/0x260 kfree+0x9b/0x160 kvfree+0x2d/0x40 bpf_map_area_free+0xe/0x20 array_map_free+0x120/0x2c0 bpf_map_free_deferred+0xd7/0x1e0 process_one_work+0x462/0x990 worker_thread+0x370/0x670 kthread+0x1b0/0x200 ret_from_fork+0x3a/0x70 ret_from_fork_asm+0x1b/0x30 Last potentially related work creation: kasan_save_stack+0x26/0x50 __kasan_record_aux_stack+0x94/0xb0 kasan_record_aux_stack_noalloc+0xb/0x20 __queue_work+0x331/0x950 queue_work_on+0x75/0x80 bpf_map_put+0xfa/0x160 bpf_map_fd_put_ptr+0xe/0x20 bpf_fd_array_map_update_elem+0x174/0x1b0 bpf_map_update_value+0x2b7/0x4a0 __sys_bpf+0x2551/0x37c0 __x64_sys_bpf+0x44/0x60 do_syscall_64+0x36/0xb0 entry_SYSCALL_64_after_hwframe+0x6e/0x76 Signed-off-by: Hou Tao <houtao1@huawei.com> Link: https://lore.kernel.org/r/20231204140425.1480317-7-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Hou Tao
Alexei Starovoitov
parent
af66bfd3c8
commit
1624918be8
141
tools/testing/selftests/bpf/prog_tests/map_in_map.c
Normal file
141
tools/testing/selftests/bpf/prog_tests/map_in_map.c
Normal file
@ -0,0 +1,141 @@
|
||||
// SPDX-License-Identifier: GPL-2.0
|
||||
/* Copyright (C) 2023. Huawei Technologies Co., Ltd */
|
||||
#define _GNU_SOURCE
|
||||
#include <unistd.h>
|
||||
#include <sys/syscall.h>
|
||||
#include <test_progs.h>
|
||||
#include <bpf/btf.h>
|
||||
#include "access_map_in_map.skel.h"
|
||||
|
||||
struct thread_ctx {
|
||||
pthread_barrier_t barrier;
|
||||
int outer_map_fd;
|
||||
int start, abort;
|
||||
int loop, err;
|
||||
};
|
||||
|
||||
static int wait_for_start_or_abort(struct thread_ctx *ctx)
|
||||
{
|
||||
while (!ctx->start && !ctx->abort)
|
||||
usleep(1);
|
||||
return ctx->abort ? -1 : 0;
|
||||
}
|
||||
|
||||
static void *update_map_fn(void *data)
|
||||
{
|
||||
struct thread_ctx *ctx = data;
|
||||
int loop = ctx->loop, err = 0;
|
||||
|
||||
if (wait_for_start_or_abort(ctx) < 0)
|
||||
return NULL;
|
||||
pthread_barrier_wait(&ctx->barrier);
|
||||
|
||||
while (loop-- > 0) {
|
||||
int fd, zero = 0;
|
||||
|
||||
fd = bpf_map_create(BPF_MAP_TYPE_ARRAY, NULL, 4, 4, 1, NULL);
|
||||
if (fd < 0) {
|
||||
err |= 1;
|
||||
pthread_barrier_wait(&ctx->barrier);
|
||||
continue;
|
||||
}
|
||||
|
||||
/* Remove the old inner map */
|
||||
if (bpf_map_update_elem(ctx->outer_map_fd, &zero, &fd, 0) < 0)
|
||||
err |= 2;
|
||||
close(fd);
|
||||
pthread_barrier_wait(&ctx->barrier);
|
||||
}
|
||||
|
||||
ctx->err = err;
|
||||
|
||||
return NULL;
|
||||
}
|
||||
|
||||
static void *access_map_fn(void *data)
|
||||
{
|
||||
struct thread_ctx *ctx = data;
|
||||
int loop = ctx->loop;
|
||||
|
||||
if (wait_for_start_or_abort(ctx) < 0)
|
||||
return NULL;
|
||||
pthread_barrier_wait(&ctx->barrier);
|
||||
|
||||
while (loop-- > 0) {
|
||||
/* Access the old inner map */
|
||||
syscall(SYS_getpgid);
|
||||
pthread_barrier_wait(&ctx->barrier);
|
||||
}
|
||||
|
||||
return NULL;
|
||||
}
|
||||
|
||||
static void test_map_in_map_access(const char *prog_name, const char *map_name)
|
||||
{
|
||||
struct access_map_in_map *skel;
|
||||
struct bpf_map *outer_map;
|
||||
struct bpf_program *prog;
|
||||
struct thread_ctx ctx;
|
||||
pthread_t tid[2];
|
||||
int err;
|
||||
|
||||
skel = access_map_in_map__open();
|
||||
if (!ASSERT_OK_PTR(skel, "access_map_in_map open"))
|
||||
return;
|
||||
|
||||
prog = bpf_object__find_program_by_name(skel->obj, prog_name);
|
||||
if (!ASSERT_OK_PTR(prog, "find program"))
|
||||
goto out;
|
||||
bpf_program__set_autoload(prog, true);
|
||||
|
||||
outer_map = bpf_object__find_map_by_name(skel->obj, map_name);
|
||||
if (!ASSERT_OK_PTR(outer_map, "find map"))
|
||||
goto out;
|
||||
|
||||
err = access_map_in_map__load(skel);
|
||||
if (!ASSERT_OK(err, "access_map_in_map load"))
|
||||
goto out;
|
||||
|
||||
err = access_map_in_map__attach(skel);
|
||||
if (!ASSERT_OK(err, "access_map_in_map attach"))
|
||||
goto out;
|
||||
|
||||
skel->bss->tgid = getpid();
|
||||
|
||||
memset(&ctx, 0, sizeof(ctx));
|
||||
pthread_barrier_init(&ctx.barrier, NULL, 2);
|
||||
ctx.outer_map_fd = bpf_map__fd(outer_map);
|
||||
ctx.loop = 4;
|
||||
|
||||
err = pthread_create(&tid[0], NULL, update_map_fn, &ctx);
|
||||
if (!ASSERT_OK(err, "close_thread"))
|
||||
goto out;
|
||||
|
||||
err = pthread_create(&tid[1], NULL, access_map_fn, &ctx);
|
||||
if (!ASSERT_OK(err, "read_thread")) {
|
||||
ctx.abort = 1;
|
||||
pthread_join(tid[0], NULL);
|
||||
goto out;
|
||||
}
|
||||
|
||||
ctx.start = 1;
|
||||
pthread_join(tid[0], NULL);
|
||||
pthread_join(tid[1], NULL);
|
||||
|
||||
ASSERT_OK(ctx.err, "err");
|
||||
out:
|
||||
access_map_in_map__destroy(skel);
|
||||
}
|
||||
|
||||
void test_map_in_map(void)
|
||||
{
|
||||
if (test__start_subtest("acc_map_in_array"))
|
||||
test_map_in_map_access("access_map_in_array", "outer_array_map");
|
||||
if (test__start_subtest("sleepable_acc_map_in_array"))
|
||||
test_map_in_map_access("sleepable_access_map_in_array", "outer_array_map");
|
||||
if (test__start_subtest("acc_map_in_htab"))
|
||||
test_map_in_map_access("access_map_in_htab", "outer_htab_map");
|
||||
if (test__start_subtest("sleepable_acc_map_in_htab"))
|
||||
test_map_in_map_access("sleepable_access_map_in_htab", "outer_htab_map");
|
||||
}
|
||||
|
||||
93
tools/testing/selftests/bpf/progs/access_map_in_map.c
Normal file
93
tools/testing/selftests/bpf/progs/access_map_in_map.c
Normal file
@ -0,0 +1,93 @@
|
||||
// SPDX-License-Identifier: GPL-2.0
|
||||
/* Copyright (C) 2023. Huawei Technologies Co., Ltd */
|
||||
#include <linux/bpf.h>
|
||||
#include <time.h>
|
||||
#include <bpf/bpf_helpers.h>
|
||||
|
||||
#include "bpf_misc.h"
|
||||
|
||||
struct inner_map_type {
|
||||
__uint(type, BPF_MAP_TYPE_ARRAY);
|
||||
__uint(key_size, 4);
|
||||
__uint(value_size, 4);
|
||||
__uint(max_entries, 1);
|
||||
} inner_map SEC(".maps");
|
||||
|
||||
struct {
|
||||
__uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
|
||||
__type(key, int);
|
||||
__type(value, int);
|
||||
__uint(max_entries, 1);
|
||||
__array(values, struct inner_map_type);
|
||||
} outer_array_map SEC(".maps") = {
|
||||
.values = {
|
||||
[0] = &inner_map,
|
||||
},
|
||||
};
|
||||
|
||||
struct {
|
||||
__uint(type, BPF_MAP_TYPE_HASH_OF_MAPS);
|
||||
__type(key, int);
|
||||
__type(value, int);
|
||||
__uint(max_entries, 1);
|
||||
__array(values, struct inner_map_type);
|
||||
} outer_htab_map SEC(".maps") = {
|
||||
.values = {
|
||||
[0] = &inner_map,
|
||||
},
|
||||
};
|
||||
|
||||
char _license[] SEC("license") = "GPL";
|
||||
|
||||
int tgid = 0;
|
||||
|
||||
static int acc_map_in_map(void *outer_map)
|
||||
{
|
||||
int i, key, value = 0xdeadbeef;
|
||||
void *inner_map;
|
||||
|
||||
if ((bpf_get_current_pid_tgid() >> 32) != tgid)
|
||||
return 0;
|
||||
|
||||
/* Find nonexistent inner map */
|
||||
key = 1;
|
||||
inner_map = bpf_map_lookup_elem(outer_map, &key);
|
||||
if (inner_map)
|
||||
return 0;
|
||||
|
||||
/* Find the old inner map */
|
||||
key = 0;
|
||||
inner_map = bpf_map_lookup_elem(outer_map, &key);
|
||||
if (!inner_map)
|
||||
return 0;
|
||||
|
||||
/* Wait for the old inner map to be replaced */
|
||||
for (i = 0; i < 2048; i++)
|
||||
bpf_map_update_elem(inner_map, &key, &value, 0);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
SEC("?kprobe/" SYS_PREFIX "sys_getpgid")
|
||||
int access_map_in_array(void *ctx)
|
||||
{
|
||||
return acc_map_in_map(&outer_array_map);
|
||||
}
|
||||
|
||||
SEC("?fentry.s/" SYS_PREFIX "sys_getpgid")
|
||||
int sleepable_access_map_in_array(void *ctx)
|
||||
{
|
||||
return acc_map_in_map(&outer_array_map);
|
||||
}
|
||||
|
||||
SEC("?kprobe/" SYS_PREFIX "sys_getpgid")
|
||||
int access_map_in_htab(void *ctx)
|
||||
{
|
||||
return acc_map_in_map(&outer_htab_map);
|
||||
}
|
||||
|
||||
SEC("?fentry.s/" SYS_PREFIX "sys_getpgid")
|
||||
int sleepable_access_map_in_htab(void *ctx)
|
||||
{
|
||||
return acc_map_in_map(&outer_htab_map);
|
||||
}
|
||||
Loading…
x
Reference in New Issue
Block a user