1095 lines
22 KiB
C
1095 lines
22 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 {
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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, __u64);
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} array_map4 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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__uint(max_entries, 4096);
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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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__failure __msg("Unreleased reference id=2")
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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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__failure __msg("Unreleased reference id=4")
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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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__failure __msg("Unreleased reference id")
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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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__failure __msg("arg 1 is an unacquired reference")
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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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__failure __msg("Expected an initialized dynptr as arg #3")
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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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__failure __msg("type=mem expected=ringbuf_mem")
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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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__failure __msg("invalid indirect read from stack")
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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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__failure __msg("invalid indirect read from stack")
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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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__failure __msg("value is outside of the allowed memory range")
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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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__failure __msg("value is outside of the allowed memory range")
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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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__failure __msg("invalid mem access 'scalar'")
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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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__failure __msg("invalid mem access 'scalar'")
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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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__failure __msg("invalid mem access 'mem_or_null'")
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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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__failure __msg("invalid mem access 'mem_or_null'")
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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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__failure __msg("invalid indirect read from stack")
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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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__failure __msg("cannot pass in dynptr at an offset=-8")
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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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__failure __msg("Expected an initialized dynptr as arg #1")
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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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__failure __msg("cannot overwrite referenced dynptr")
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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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__failure __msg("cannot overwrite referenced dynptr")
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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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__failure __msg("cannot overwrite referenced dynptr")
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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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__failure __msg("type=map_value expected=fp")
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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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__failure __msg("invalid read from stack")
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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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__failure __msg("cannot pass in dynptr at an offset")
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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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__failure __msg("invalid read from stack")
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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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|
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/* this should fail */
|
|
memcpy(&val, (void *)&ptr1 + 8, sizeof(val));
|
|
|
|
bpf_ringbuf_discard_dynptr(&ptr1, 0);
|
|
bpf_ringbuf_discard_dynptr(&ptr2, 0);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int invalid_read4_callback(__u32 index, void *data)
|
|
{
|
|
/* this should fail */
|
|
val = *(__u32 *)data;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* A direct read within a callback function should fail */
|
|
SEC("?raw_tp")
|
|
__failure __msg("invalid read from stack")
|
|
int invalid_read4(void *ctx)
|
|
{
|
|
struct bpf_dynptr ptr;
|
|
|
|
bpf_ringbuf_reserve_dynptr(&ringbuf, 64, 0, &ptr);
|
|
|
|
bpf_loop(10, invalid_read4_callback, &ptr, 0);
|
|
|
|
bpf_ringbuf_submit_dynptr(&ptr, 0);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Initializing a dynptr on an offset should fail */
|
|
SEC("?raw_tp")
|
|
__failure __msg("cannot pass in dynptr at an offset=0")
|
|
int invalid_offset(void *ctx)
|
|
{
|
|
struct bpf_dynptr ptr;
|
|
|
|
/* this should fail */
|
|
bpf_ringbuf_reserve_dynptr(&ringbuf, 64, 0, &ptr + 1);
|
|
|
|
bpf_ringbuf_discard_dynptr(&ptr, 0);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Can't release a dynptr twice */
|
|
SEC("?raw_tp")
|
|
__failure __msg("arg 1 is an unacquired reference")
|
|
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 callback function, fails
|
|
*/
|
|
SEC("?raw_tp")
|
|
__failure __msg("arg 1 is an unacquired reference")
|
|
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")
|
|
__failure __msg("Unsupported reg type fp for bpf_dynptr_from_mem data")
|
|
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;
|
|
}
|
|
|
|
SEC("?tc")
|
|
__failure __msg("cannot overwrite referenced dynptr") __log_level(2)
|
|
int dynptr_pruning_overwrite(struct __sk_buff *ctx)
|
|
{
|
|
asm volatile (
|
|
"r9 = 0xeB9F; \
|
|
r6 = %[ringbuf] ll; \
|
|
r1 = r6; \
|
|
r2 = 8; \
|
|
r3 = 0; \
|
|
r4 = r10; \
|
|
r4 += -16; \
|
|
call %[bpf_ringbuf_reserve_dynptr]; \
|
|
if r0 == 0 goto pjmp1; \
|
|
goto pjmp2; \
|
|
pjmp1: \
|
|
*(u64 *)(r10 - 16) = r9; \
|
|
pjmp2: \
|
|
r1 = r10; \
|
|
r1 += -16; \
|
|
r2 = 0; \
|
|
call %[bpf_ringbuf_discard_dynptr]; "
|
|
:
|
|
: __imm(bpf_ringbuf_reserve_dynptr),
|
|
__imm(bpf_ringbuf_discard_dynptr),
|
|
__imm_addr(ringbuf)
|
|
: __clobber_all
|
|
);
|
|
return 0;
|
|
}
|
|
|
|
SEC("?tc")
|
|
__success __msg("12: safe") __log_level(2)
|
|
int dynptr_pruning_stacksafe(struct __sk_buff *ctx)
|
|
{
|
|
asm volatile (
|
|
"r9 = 0xeB9F; \
|
|
r6 = %[ringbuf] ll; \
|
|
r1 = r6; \
|
|
r2 = 8; \
|
|
r3 = 0; \
|
|
r4 = r10; \
|
|
r4 += -16; \
|
|
call %[bpf_ringbuf_reserve_dynptr]; \
|
|
if r0 == 0 goto stjmp1; \
|
|
goto stjmp2; \
|
|
stjmp1: \
|
|
r9 = r9; \
|
|
stjmp2: \
|
|
r1 = r10; \
|
|
r1 += -16; \
|
|
r2 = 0; \
|
|
call %[bpf_ringbuf_discard_dynptr]; "
|
|
:
|
|
: __imm(bpf_ringbuf_reserve_dynptr),
|
|
__imm(bpf_ringbuf_discard_dynptr),
|
|
__imm_addr(ringbuf)
|
|
: __clobber_all
|
|
);
|
|
return 0;
|
|
}
|
|
|
|
SEC("?tc")
|
|
__failure __msg("cannot overwrite referenced dynptr") __log_level(2)
|
|
int dynptr_pruning_type_confusion(struct __sk_buff *ctx)
|
|
{
|
|
asm volatile (
|
|
"r6 = %[array_map4] ll; \
|
|
r7 = %[ringbuf] ll; \
|
|
r1 = r6; \
|
|
r2 = r10; \
|
|
r2 += -8; \
|
|
r9 = 0; \
|
|
*(u64 *)(r2 + 0) = r9; \
|
|
r3 = r10; \
|
|
r3 += -24; \
|
|
r9 = 0xeB9FeB9F; \
|
|
*(u64 *)(r10 - 16) = r9; \
|
|
*(u64 *)(r10 - 24) = r9; \
|
|
r9 = 0; \
|
|
r4 = 0; \
|
|
r8 = r2; \
|
|
call %[bpf_map_update_elem]; \
|
|
r1 = r6; \
|
|
r2 = r8; \
|
|
call %[bpf_map_lookup_elem]; \
|
|
if r0 != 0 goto tjmp1; \
|
|
exit; \
|
|
tjmp1: \
|
|
r8 = r0; \
|
|
r1 = r7; \
|
|
r2 = 8; \
|
|
r3 = 0; \
|
|
r4 = r10; \
|
|
r4 += -16; \
|
|
r0 = *(u64 *)(r0 + 0); \
|
|
call %[bpf_ringbuf_reserve_dynptr]; \
|
|
if r0 == 0 goto tjmp2; \
|
|
r8 = r8; \
|
|
r8 = r8; \
|
|
r8 = r8; \
|
|
r8 = r8; \
|
|
r8 = r8; \
|
|
r8 = r8; \
|
|
r8 = r8; \
|
|
goto tjmp3; \
|
|
tjmp2: \
|
|
*(u64 *)(r10 - 8) = r9; \
|
|
*(u64 *)(r10 - 16) = r9; \
|
|
r1 = r8; \
|
|
r1 += 8; \
|
|
r2 = 0; \
|
|
r3 = 0; \
|
|
r4 = r10; \
|
|
r4 += -16; \
|
|
call %[bpf_dynptr_from_mem]; \
|
|
tjmp3: \
|
|
r1 = r10; \
|
|
r1 += -16; \
|
|
r2 = 0; \
|
|
call %[bpf_ringbuf_discard_dynptr]; "
|
|
:
|
|
: __imm(bpf_map_update_elem),
|
|
__imm(bpf_map_lookup_elem),
|
|
__imm(bpf_ringbuf_reserve_dynptr),
|
|
__imm(bpf_dynptr_from_mem),
|
|
__imm(bpf_ringbuf_discard_dynptr),
|
|
__imm_addr(array_map4),
|
|
__imm_addr(ringbuf)
|
|
: __clobber_all
|
|
);
|
|
return 0;
|
|
}
|
|
|
|
SEC("?tc")
|
|
__failure __msg("dynptr has to be at a constant offset") __log_level(2)
|
|
int dynptr_var_off_overwrite(struct __sk_buff *ctx)
|
|
{
|
|
asm volatile (
|
|
"r9 = 16; \
|
|
*(u32 *)(r10 - 4) = r9; \
|
|
r8 = *(u32 *)(r10 - 4); \
|
|
if r8 >= 0 goto vjmp1; \
|
|
r0 = 1; \
|
|
exit; \
|
|
vjmp1: \
|
|
if r8 <= 16 goto vjmp2; \
|
|
r0 = 1; \
|
|
exit; \
|
|
vjmp2: \
|
|
r8 &= 16; \
|
|
r1 = %[ringbuf] ll; \
|
|
r2 = 8; \
|
|
r3 = 0; \
|
|
r4 = r10; \
|
|
r4 += -32; \
|
|
r4 += r8; \
|
|
call %[bpf_ringbuf_reserve_dynptr]; \
|
|
r9 = 0xeB9F; \
|
|
*(u64 *)(r10 - 16) = r9; \
|
|
r1 = r10; \
|
|
r1 += -32; \
|
|
r1 += r8; \
|
|
r2 = 0; \
|
|
call %[bpf_ringbuf_discard_dynptr]; "
|
|
:
|
|
: __imm(bpf_ringbuf_reserve_dynptr),
|
|
__imm(bpf_ringbuf_discard_dynptr),
|
|
__imm_addr(ringbuf)
|
|
: __clobber_all
|
|
);
|
|
return 0;
|
|
}
|
|
|
|
SEC("?tc")
|
|
__failure __msg("cannot overwrite referenced dynptr") __log_level(2)
|
|
int dynptr_partial_slot_invalidate(struct __sk_buff *ctx)
|
|
{
|
|
asm volatile (
|
|
"r6 = %[ringbuf] ll; \
|
|
r7 = %[array_map4] ll; \
|
|
r1 = r7; \
|
|
r2 = r10; \
|
|
r2 += -8; \
|
|
r9 = 0; \
|
|
*(u64 *)(r2 + 0) = r9; \
|
|
r3 = r2; \
|
|
r4 = 0; \
|
|
r8 = r2; \
|
|
call %[bpf_map_update_elem]; \
|
|
r1 = r7; \
|
|
r2 = r8; \
|
|
call %[bpf_map_lookup_elem]; \
|
|
if r0 != 0 goto sjmp1; \
|
|
exit; \
|
|
sjmp1: \
|
|
r7 = r0; \
|
|
r1 = r6; \
|
|
r2 = 8; \
|
|
r3 = 0; \
|
|
r4 = r10; \
|
|
r4 += -24; \
|
|
call %[bpf_ringbuf_reserve_dynptr]; \
|
|
*(u64 *)(r10 - 16) = r9; \
|
|
r1 = r7; \
|
|
r2 = 8; \
|
|
r3 = 0; \
|
|
r4 = r10; \
|
|
r4 += -16; \
|
|
call %[bpf_dynptr_from_mem]; \
|
|
r1 = r10; \
|
|
r1 += -512; \
|
|
r2 = 488; \
|
|
r3 = r10; \
|
|
r3 += -24; \
|
|
r4 = 0; \
|
|
r5 = 0; \
|
|
call %[bpf_dynptr_read]; \
|
|
r8 = 1; \
|
|
if r0 != 0 goto sjmp2; \
|
|
r8 = 0; \
|
|
sjmp2: \
|
|
r1 = r10; \
|
|
r1 += -24; \
|
|
r2 = 0; \
|
|
call %[bpf_ringbuf_discard_dynptr]; "
|
|
:
|
|
: __imm(bpf_map_update_elem),
|
|
__imm(bpf_map_lookup_elem),
|
|
__imm(bpf_ringbuf_reserve_dynptr),
|
|
__imm(bpf_ringbuf_discard_dynptr),
|
|
__imm(bpf_dynptr_from_mem),
|
|
__imm(bpf_dynptr_read),
|
|
__imm_addr(ringbuf),
|
|
__imm_addr(array_map4)
|
|
: __clobber_all
|
|
);
|
|
return 0;
|
|
}
|
|
|
|
/* Test that it is allowed to overwrite unreferenced dynptr. */
|
|
SEC("?raw_tp")
|
|
__success
|
|
int dynptr_overwrite_unref(void *ctx)
|
|
{
|
|
struct bpf_dynptr ptr;
|
|
|
|
if (get_map_val_dynptr(&ptr))
|
|
return 0;
|
|
if (get_map_val_dynptr(&ptr))
|
|
return 0;
|
|
if (get_map_val_dynptr(&ptr))
|
|
return 0;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Test that slices are invalidated on reinitializing a dynptr. */
|
|
SEC("?raw_tp")
|
|
__failure __msg("invalid mem access 'scalar'")
|
|
int dynptr_invalidate_slice_reinit(void *ctx)
|
|
{
|
|
struct bpf_dynptr ptr;
|
|
__u8 *p;
|
|
|
|
if (get_map_val_dynptr(&ptr))
|
|
return 0;
|
|
p = bpf_dynptr_data(&ptr, 0, 1);
|
|
if (!p)
|
|
return 0;
|
|
if (get_map_val_dynptr(&ptr))
|
|
return 0;
|
|
/* this should fail */
|
|
return *p;
|
|
}
|
|
|
|
/* Invalidation of dynptr slices on destruction of dynptr should not miss
|
|
* mem_or_null pointers.
|
|
*/
|
|
SEC("?raw_tp")
|
|
__failure __msg("R1 type=scalar expected=percpu_ptr_")
|
|
int dynptr_invalidate_slice_or_null(void *ctx)
|
|
{
|
|
struct bpf_dynptr ptr;
|
|
__u8 *p;
|
|
|
|
if (get_map_val_dynptr(&ptr))
|
|
return 0;
|
|
|
|
p = bpf_dynptr_data(&ptr, 0, 1);
|
|
*(__u8 *)&ptr = 0;
|
|
/* this should fail */
|
|
bpf_this_cpu_ptr(p);
|
|
return 0;
|
|
}
|
|
|
|
/* Destruction of dynptr should also any slices obtained from it */
|
|
SEC("?raw_tp")
|
|
__failure __msg("R7 invalid mem access 'scalar'")
|
|
int dynptr_invalidate_slice_failure(void *ctx)
|
|
{
|
|
struct bpf_dynptr ptr1;
|
|
struct bpf_dynptr ptr2;
|
|
__u8 *p1, *p2;
|
|
|
|
if (get_map_val_dynptr(&ptr1))
|
|
return 0;
|
|
if (get_map_val_dynptr(&ptr2))
|
|
return 0;
|
|
|
|
p1 = bpf_dynptr_data(&ptr1, 0, 1);
|
|
if (!p1)
|
|
return 0;
|
|
p2 = bpf_dynptr_data(&ptr2, 0, 1);
|
|
if (!p2)
|
|
return 0;
|
|
|
|
*(__u8 *)&ptr1 = 0;
|
|
/* this should fail */
|
|
return *p1;
|
|
}
|
|
|
|
/* Invalidation of slices should be scoped and should not prevent dereferencing
|
|
* slices of another dynptr after destroying unrelated dynptr
|
|
*/
|
|
SEC("?raw_tp")
|
|
__success
|
|
int dynptr_invalidate_slice_success(void *ctx)
|
|
{
|
|
struct bpf_dynptr ptr1;
|
|
struct bpf_dynptr ptr2;
|
|
__u8 *p1, *p2;
|
|
|
|
if (get_map_val_dynptr(&ptr1))
|
|
return 1;
|
|
if (get_map_val_dynptr(&ptr2))
|
|
return 1;
|
|
|
|
p1 = bpf_dynptr_data(&ptr1, 0, 1);
|
|
if (!p1)
|
|
return 1;
|
|
p2 = bpf_dynptr_data(&ptr2, 0, 1);
|
|
if (!p2)
|
|
return 1;
|
|
|
|
*(__u8 *)&ptr1 = 0;
|
|
return *p2;
|
|
}
|
|
|
|
/* Overwriting referenced dynptr should be rejected */
|
|
SEC("?raw_tp")
|
|
__failure __msg("cannot overwrite referenced dynptr")
|
|
int dynptr_overwrite_ref(void *ctx)
|
|
{
|
|
struct bpf_dynptr ptr;
|
|
|
|
bpf_ringbuf_reserve_dynptr(&ringbuf, 64, 0, &ptr);
|
|
/* this should fail */
|
|
if (get_map_val_dynptr(&ptr))
|
|
bpf_ringbuf_discard_dynptr(&ptr, 0);
|
|
return 0;
|
|
}
|
|
|
|
/* Reject writes to dynptr slot from bpf_dynptr_read */
|
|
SEC("?raw_tp")
|
|
__failure __msg("potential write to dynptr at off=-16")
|
|
int dynptr_read_into_slot(void *ctx)
|
|
{
|
|
union {
|
|
struct {
|
|
char _pad[48];
|
|
struct bpf_dynptr ptr;
|
|
};
|
|
char buf[64];
|
|
} data;
|
|
|
|
bpf_ringbuf_reserve_dynptr(&ringbuf, 64, 0, &data.ptr);
|
|
/* this should fail */
|
|
bpf_dynptr_read(data.buf, sizeof(data.buf), &data.ptr, 0, 0);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Reject writes to dynptr slot for uninit arg */
|
|
SEC("?raw_tp")
|
|
__failure __msg("potential write to dynptr at off=-16")
|
|
int uninit_write_into_slot(void *ctx)
|
|
{
|
|
struct {
|
|
char buf[64];
|
|
struct bpf_dynptr ptr;
|
|
} data;
|
|
|
|
bpf_ringbuf_reserve_dynptr(&ringbuf, 80, 0, &data.ptr);
|
|
/* this should fail */
|
|
bpf_get_current_comm(data.buf, 80);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int callback(__u32 index, void *data)
|
|
{
|
|
*(__u32 *)data = 123;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* If the dynptr is written into in a callback function, its data
|
|
* slices should be invalidated as well.
|
|
*/
|
|
SEC("?raw_tp")
|
|
__failure __msg("invalid mem access 'scalar'")
|
|
int invalid_data_slices(void *ctx)
|
|
{
|
|
struct bpf_dynptr ptr;
|
|
__u32 *slice;
|
|
|
|
if (get_map_val_dynptr(&ptr))
|
|
return 0;
|
|
|
|
slice = bpf_dynptr_data(&ptr, 0, sizeof(__u32));
|
|
if (!slice)
|
|
return 0;
|
|
|
|
bpf_loop(10, callback, &ptr, 0);
|
|
|
|
/* this should fail */
|
|
*slice = 1;
|
|
|
|
return 0;
|
|
}
|