625 lines
12 KiB
C
625 lines
12 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* Copyright (c) 2022 Facebook */
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#include <errno.h>
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#include <string.h>
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#include <linux/bpf.h>
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#include <bpf/bpf_helpers.h>
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#include "bpf_misc.h"
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char _license[] SEC("license") = "GPL";
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struct test_info {
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int x;
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struct bpf_dynptr ptr;
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};
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struct {
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__uint(type, BPF_MAP_TYPE_ARRAY);
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__uint(max_entries, 1);
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__type(key, __u32);
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__type(value, struct bpf_dynptr);
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} array_map1 SEC(".maps");
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struct {
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__uint(type, BPF_MAP_TYPE_ARRAY);
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__uint(max_entries, 1);
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__type(key, __u32);
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__type(value, struct test_info);
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} array_map2 SEC(".maps");
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struct {
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__uint(type, BPF_MAP_TYPE_ARRAY);
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__uint(max_entries, 1);
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__type(key, __u32);
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__type(value, __u32);
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} array_map3 SEC(".maps");
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struct sample {
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int pid;
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long value;
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char comm[16];
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};
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struct {
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__uint(type, BPF_MAP_TYPE_RINGBUF);
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} ringbuf SEC(".maps");
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int err, val;
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static int get_map_val_dynptr(struct bpf_dynptr *ptr)
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{
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__u32 key = 0, *map_val;
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bpf_map_update_elem(&array_map3, &key, &val, 0);
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map_val = bpf_map_lookup_elem(&array_map3, &key);
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if (!map_val)
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return -ENOENT;
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bpf_dynptr_from_mem(map_val, sizeof(*map_val), 0, ptr);
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return 0;
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}
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/* Every bpf_ringbuf_reserve_dynptr call must have a corresponding
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* bpf_ringbuf_submit/discard_dynptr call
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*/
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SEC("?raw_tp")
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int ringbuf_missing_release1(void *ctx)
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{
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struct bpf_dynptr ptr;
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bpf_ringbuf_reserve_dynptr(&ringbuf, val, 0, &ptr);
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/* missing a call to bpf_ringbuf_discard/submit_dynptr */
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return 0;
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}
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SEC("?raw_tp")
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int ringbuf_missing_release2(void *ctx)
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{
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struct bpf_dynptr ptr1, ptr2;
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struct sample *sample;
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bpf_ringbuf_reserve_dynptr(&ringbuf, sizeof(*sample), 0, &ptr1);
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bpf_ringbuf_reserve_dynptr(&ringbuf, sizeof(*sample), 0, &ptr2);
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sample = bpf_dynptr_data(&ptr1, 0, sizeof(*sample));
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if (!sample) {
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bpf_ringbuf_discard_dynptr(&ptr1, 0);
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bpf_ringbuf_discard_dynptr(&ptr2, 0);
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return 0;
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}
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bpf_ringbuf_submit_dynptr(&ptr1, 0);
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/* missing a call to bpf_ringbuf_discard/submit_dynptr on ptr2 */
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return 0;
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}
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static int missing_release_callback_fn(__u32 index, void *data)
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{
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struct bpf_dynptr ptr;
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bpf_ringbuf_reserve_dynptr(&ringbuf, val, 0, &ptr);
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/* missing a call to bpf_ringbuf_discard/submit_dynptr */
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return 0;
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}
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/* Any dynptr initialized within a callback must have bpf_dynptr_put called */
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SEC("?raw_tp")
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int ringbuf_missing_release_callback(void *ctx)
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{
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bpf_loop(10, missing_release_callback_fn, NULL, 0);
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return 0;
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}
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/* Can't call bpf_ringbuf_submit/discard_dynptr on a non-initialized dynptr */
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SEC("?raw_tp")
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int ringbuf_release_uninit_dynptr(void *ctx)
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{
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struct bpf_dynptr ptr;
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/* this should fail */
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bpf_ringbuf_submit_dynptr(&ptr, 0);
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return 0;
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}
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/* A dynptr can't be used after it has been invalidated */
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SEC("?raw_tp")
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int use_after_invalid(void *ctx)
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{
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struct bpf_dynptr ptr;
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char read_data[64];
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bpf_ringbuf_reserve_dynptr(&ringbuf, sizeof(read_data), 0, &ptr);
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bpf_dynptr_read(read_data, sizeof(read_data), &ptr, 0, 0);
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bpf_ringbuf_submit_dynptr(&ptr, 0);
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/* this should fail */
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bpf_dynptr_read(read_data, sizeof(read_data), &ptr, 0, 0);
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return 0;
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}
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/* Can't call non-dynptr ringbuf APIs on a dynptr ringbuf sample */
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SEC("?raw_tp")
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int ringbuf_invalid_api(void *ctx)
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{
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struct bpf_dynptr ptr;
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struct sample *sample;
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bpf_ringbuf_reserve_dynptr(&ringbuf, sizeof(*sample), 0, &ptr);
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sample = bpf_dynptr_data(&ptr, 0, sizeof(*sample));
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if (!sample)
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goto done;
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sample->pid = 123;
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/* invalid API use. need to use dynptr API to submit/discard */
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bpf_ringbuf_submit(sample, 0);
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done:
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bpf_ringbuf_discard_dynptr(&ptr, 0);
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return 0;
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}
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/* Can't add a dynptr to a map */
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SEC("?raw_tp")
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int add_dynptr_to_map1(void *ctx)
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{
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struct bpf_dynptr ptr;
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int key = 0;
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bpf_ringbuf_reserve_dynptr(&ringbuf, val, 0, &ptr);
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/* this should fail */
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bpf_map_update_elem(&array_map1, &key, &ptr, 0);
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bpf_ringbuf_submit_dynptr(&ptr, 0);
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return 0;
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}
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/* Can't add a struct with an embedded dynptr to a map */
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SEC("?raw_tp")
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int add_dynptr_to_map2(void *ctx)
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{
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struct test_info x;
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int key = 0;
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bpf_ringbuf_reserve_dynptr(&ringbuf, val, 0, &x.ptr);
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/* this should fail */
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bpf_map_update_elem(&array_map2, &key, &x, 0);
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bpf_ringbuf_submit_dynptr(&x.ptr, 0);
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return 0;
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}
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/* A data slice can't be accessed out of bounds */
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SEC("?raw_tp")
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int data_slice_out_of_bounds_ringbuf(void *ctx)
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{
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struct bpf_dynptr ptr;
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void *data;
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bpf_ringbuf_reserve_dynptr(&ringbuf, 8, 0, &ptr);
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data = bpf_dynptr_data(&ptr, 0, 8);
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if (!data)
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goto done;
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/* can't index out of bounds of the data slice */
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val = *((char *)data + 8);
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done:
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bpf_ringbuf_submit_dynptr(&ptr, 0);
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return 0;
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}
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SEC("?raw_tp")
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int data_slice_out_of_bounds_map_value(void *ctx)
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{
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__u32 key = 0, map_val;
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struct bpf_dynptr ptr;
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void *data;
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get_map_val_dynptr(&ptr);
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data = bpf_dynptr_data(&ptr, 0, sizeof(map_val));
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if (!data)
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return 0;
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/* can't index out of bounds of the data slice */
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val = *((char *)data + (sizeof(map_val) + 1));
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return 0;
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}
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/* A data slice can't be used after it has been released */
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SEC("?raw_tp")
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int data_slice_use_after_release1(void *ctx)
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{
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struct bpf_dynptr ptr;
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struct sample *sample;
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bpf_ringbuf_reserve_dynptr(&ringbuf, sizeof(*sample), 0, &ptr);
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sample = bpf_dynptr_data(&ptr, 0, sizeof(*sample));
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if (!sample)
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goto done;
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sample->pid = 123;
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bpf_ringbuf_submit_dynptr(&ptr, 0);
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/* this should fail */
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val = sample->pid;
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return 0;
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done:
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bpf_ringbuf_discard_dynptr(&ptr, 0);
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return 0;
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}
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/* A data slice can't be used after it has been released.
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*
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* This tests the case where the data slice tracks a dynptr (ptr2)
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* that is at a non-zero offset from the frame pointer (ptr1 is at fp,
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* ptr2 is at fp - 16).
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*/
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SEC("?raw_tp")
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int data_slice_use_after_release2(void *ctx)
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{
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struct bpf_dynptr ptr1, ptr2;
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struct sample *sample;
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bpf_ringbuf_reserve_dynptr(&ringbuf, 64, 0, &ptr1);
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bpf_ringbuf_reserve_dynptr(&ringbuf, sizeof(*sample), 0, &ptr2);
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sample = bpf_dynptr_data(&ptr2, 0, sizeof(*sample));
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if (!sample)
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goto done;
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sample->pid = 23;
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bpf_ringbuf_submit_dynptr(&ptr2, 0);
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/* this should fail */
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sample->pid = 23;
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bpf_ringbuf_submit_dynptr(&ptr1, 0);
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return 0;
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done:
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bpf_ringbuf_discard_dynptr(&ptr2, 0);
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bpf_ringbuf_discard_dynptr(&ptr1, 0);
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return 0;
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}
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/* A data slice must be first checked for NULL */
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SEC("?raw_tp")
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int data_slice_missing_null_check1(void *ctx)
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{
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struct bpf_dynptr ptr;
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void *data;
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bpf_ringbuf_reserve_dynptr(&ringbuf, 8, 0, &ptr);
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data = bpf_dynptr_data(&ptr, 0, 8);
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/* missing if (!data) check */
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/* this should fail */
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*(__u8 *)data = 3;
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bpf_ringbuf_submit_dynptr(&ptr, 0);
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return 0;
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}
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/* A data slice can't be dereferenced if it wasn't checked for null */
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SEC("?raw_tp")
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int data_slice_missing_null_check2(void *ctx)
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{
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struct bpf_dynptr ptr;
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__u64 *data1, *data2;
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bpf_ringbuf_reserve_dynptr(&ringbuf, 16, 0, &ptr);
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data1 = bpf_dynptr_data(&ptr, 0, 8);
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data2 = bpf_dynptr_data(&ptr, 0, 8);
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if (data1)
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/* this should fail */
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*data2 = 3;
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done:
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bpf_ringbuf_discard_dynptr(&ptr, 0);
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return 0;
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}
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/* Can't pass in a dynptr as an arg to a helper function that doesn't take in a
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* dynptr argument
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*/
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SEC("?raw_tp")
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int invalid_helper1(void *ctx)
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{
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struct bpf_dynptr ptr;
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get_map_val_dynptr(&ptr);
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/* this should fail */
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bpf_strncmp((const char *)&ptr, sizeof(ptr), "hello!");
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return 0;
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}
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/* A dynptr can't be passed into a helper function at a non-zero offset */
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SEC("?raw_tp")
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int invalid_helper2(void *ctx)
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{
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struct bpf_dynptr ptr;
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char read_data[64];
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get_map_val_dynptr(&ptr);
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/* this should fail */
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bpf_dynptr_read(read_data, sizeof(read_data), (void *)&ptr + 8, 0, 0);
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return 0;
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}
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/* A bpf_dynptr is invalidated if it's been written into */
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SEC("?raw_tp")
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int invalid_write1(void *ctx)
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{
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struct bpf_dynptr ptr;
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void *data;
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__u8 x = 0;
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get_map_val_dynptr(&ptr);
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memcpy(&ptr, &x, sizeof(x));
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/* this should fail */
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data = bpf_dynptr_data(&ptr, 0, 1);
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return 0;
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}
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/*
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* A bpf_dynptr can't be used as a dynptr if it has been written into at a fixed
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* offset
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*/
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SEC("?raw_tp")
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int invalid_write2(void *ctx)
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{
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struct bpf_dynptr ptr;
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char read_data[64];
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__u8 x = 0;
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bpf_ringbuf_reserve_dynptr(&ringbuf, 64, 0, &ptr);
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memcpy((void *)&ptr + 8, &x, sizeof(x));
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/* this should fail */
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bpf_dynptr_read(read_data, sizeof(read_data), &ptr, 0, 0);
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bpf_ringbuf_submit_dynptr(&ptr, 0);
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return 0;
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}
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/*
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* A bpf_dynptr can't be used as a dynptr if it has been written into at a
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* non-const offset
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*/
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SEC("?raw_tp")
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int invalid_write3(void *ctx)
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{
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struct bpf_dynptr ptr;
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char stack_buf[16];
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unsigned long len;
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__u8 x = 0;
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bpf_ringbuf_reserve_dynptr(&ringbuf, 8, 0, &ptr);
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memcpy(stack_buf, &val, sizeof(val));
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len = stack_buf[0] & 0xf;
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memcpy((void *)&ptr + len, &x, sizeof(x));
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/* this should fail */
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bpf_ringbuf_submit_dynptr(&ptr, 0);
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return 0;
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}
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static int invalid_write4_callback(__u32 index, void *data)
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{
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*(__u32 *)data = 123;
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return 0;
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}
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/* If the dynptr is written into in a callback function, it should
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* be invalidated as a dynptr
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*/
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SEC("?raw_tp")
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int invalid_write4(void *ctx)
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{
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struct bpf_dynptr ptr;
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bpf_ringbuf_reserve_dynptr(&ringbuf, 64, 0, &ptr);
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bpf_loop(10, invalid_write4_callback, &ptr, 0);
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/* this should fail */
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bpf_ringbuf_submit_dynptr(&ptr, 0);
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return 0;
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}
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/* A globally-defined bpf_dynptr can't be used (it must reside as a stack frame) */
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struct bpf_dynptr global_dynptr;
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SEC("?raw_tp")
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int global(void *ctx)
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{
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/* this should fail */
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bpf_ringbuf_reserve_dynptr(&ringbuf, 16, 0, &global_dynptr);
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bpf_ringbuf_discard_dynptr(&global_dynptr, 0);
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return 0;
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}
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/* A direct read should fail */
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SEC("?raw_tp")
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int invalid_read1(void *ctx)
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{
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struct bpf_dynptr ptr;
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bpf_ringbuf_reserve_dynptr(&ringbuf, 64, 0, &ptr);
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/* this should fail */
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val = *(int *)&ptr;
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bpf_ringbuf_discard_dynptr(&ptr, 0);
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return 0;
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}
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/* A direct read at an offset should fail */
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SEC("?raw_tp")
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int invalid_read2(void *ctx)
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{
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struct bpf_dynptr ptr;
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char read_data[64];
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get_map_val_dynptr(&ptr);
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/* this should fail */
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bpf_dynptr_read(read_data, sizeof(read_data), (void *)&ptr + 1, 0, 0);
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return 0;
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}
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/* A direct read at an offset into the lower stack slot should fail */
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SEC("?raw_tp")
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int invalid_read3(void *ctx)
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{
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struct bpf_dynptr ptr1, ptr2;
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bpf_ringbuf_reserve_dynptr(&ringbuf, 16, 0, &ptr1);
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bpf_ringbuf_reserve_dynptr(&ringbuf, 16, 0, &ptr2);
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/* this should fail */
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memcpy(&val, (void *)&ptr1 + 8, sizeof(val));
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bpf_ringbuf_discard_dynptr(&ptr1, 0);
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bpf_ringbuf_discard_dynptr(&ptr2, 0);
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return 0;
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}
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static int invalid_read4_callback(__u32 index, void *data)
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{
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/* this should fail */
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val = *(__u32 *)data;
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return 0;
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}
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/* A direct read within a callback function should fail */
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SEC("?raw_tp")
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int invalid_read4(void *ctx)
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{
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struct bpf_dynptr ptr;
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bpf_ringbuf_reserve_dynptr(&ringbuf, 64, 0, &ptr);
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bpf_loop(10, invalid_read4_callback, &ptr, 0);
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bpf_ringbuf_submit_dynptr(&ptr, 0);
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return 0;
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}
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/* Initializing a dynptr on an offset should fail */
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SEC("?raw_tp")
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int invalid_offset(void *ctx)
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{
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struct bpf_dynptr ptr;
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/* this should fail */
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bpf_ringbuf_reserve_dynptr(&ringbuf, 64, 0, &ptr + 1);
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bpf_ringbuf_discard_dynptr(&ptr, 0);
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return 0;
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}
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/* Can't release a dynptr twice */
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SEC("?raw_tp")
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int release_twice(void *ctx)
|
|
{
|
|
struct bpf_dynptr ptr;
|
|
|
|
bpf_ringbuf_reserve_dynptr(&ringbuf, 16, 0, &ptr);
|
|
|
|
bpf_ringbuf_discard_dynptr(&ptr, 0);
|
|
|
|
/* this second release should fail */
|
|
bpf_ringbuf_discard_dynptr(&ptr, 0);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int release_twice_callback_fn(__u32 index, void *data)
|
|
{
|
|
/* this should fail */
|
|
bpf_ringbuf_discard_dynptr(data, 0);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Test that releasing a dynptr twice, where one of the releases happens
|
|
* within a calback function, fails
|
|
*/
|
|
SEC("?raw_tp")
|
|
int release_twice_callback(void *ctx)
|
|
{
|
|
struct bpf_dynptr ptr;
|
|
|
|
bpf_ringbuf_reserve_dynptr(&ringbuf, 32, 0, &ptr);
|
|
|
|
bpf_ringbuf_discard_dynptr(&ptr, 0);
|
|
|
|
bpf_loop(10, release_twice_callback_fn, &ptr, 0);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Reject unsupported local mem types for dynptr_from_mem API */
|
|
SEC("?raw_tp")
|
|
int dynptr_from_mem_invalid_api(void *ctx)
|
|
{
|
|
struct bpf_dynptr ptr;
|
|
int x = 0;
|
|
|
|
/* this should fail */
|
|
bpf_dynptr_from_mem(&x, sizeof(x), 0, &ptr);
|
|
|
|
return 0;
|
|
}
|