178 lines
		
	
	
		
			3.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			178 lines
		
	
	
		
			3.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0
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/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
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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 sample {
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	int pid;
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	int seq;
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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_USER_RINGBUF);
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} user_ringbuf SEC(".maps");
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static long
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bad_access1(struct bpf_dynptr *dynptr, void *context)
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{
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	const struct sample *sample;
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	sample = bpf_dynptr_data(dynptr - 1, 0, sizeof(*sample));
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	bpf_printk("Was able to pass bad pointer %lx\n", (__u64)dynptr - 1);
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	return 0;
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}
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/* A callback that accesses a dynptr in a bpf_user_ringbuf_drain callback should
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 * not be able to read before the pointer.
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 */
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SEC("?raw_tp/sys_nanosleep")
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int user_ringbuf_callback_bad_access1(void *ctx)
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{
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	bpf_user_ringbuf_drain(&user_ringbuf, bad_access1, NULL, 0);
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	return 0;
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}
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static long
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bad_access2(struct bpf_dynptr *dynptr, void *context)
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{
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	const struct sample *sample;
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	sample = bpf_dynptr_data(dynptr + 1, 0, sizeof(*sample));
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	bpf_printk("Was able to pass bad pointer %lx\n", (__u64)dynptr + 1);
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	return 0;
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}
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/* A callback that accesses a dynptr in a bpf_user_ringbuf_drain callback should
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 * not be able to read past the end of the pointer.
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 */
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SEC("?raw_tp/sys_nanosleep")
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int user_ringbuf_callback_bad_access2(void *ctx)
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{
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	bpf_user_ringbuf_drain(&user_ringbuf, bad_access2, NULL, 0);
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	return 0;
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}
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static long
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write_forbidden(struct bpf_dynptr *dynptr, void *context)
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{
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	*((long *)dynptr) = 0;
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	return 0;
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}
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/* A callback that accesses a dynptr in a bpf_user_ringbuf_drain callback should
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 * not be able to write to that pointer.
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 */
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SEC("?raw_tp/sys_nanosleep")
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int user_ringbuf_callback_write_forbidden(void *ctx)
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{
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	bpf_user_ringbuf_drain(&user_ringbuf, write_forbidden, NULL, 0);
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	return 0;
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}
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static long
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null_context_write(struct bpf_dynptr *dynptr, void *context)
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{
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	*((__u64 *)context) = 0;
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	return 0;
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}
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/* A callback that accesses a dynptr in a bpf_user_ringbuf_drain callback should
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 * not be able to write to that pointer.
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 */
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SEC("?raw_tp/sys_nanosleep")
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int user_ringbuf_callback_null_context_write(void *ctx)
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{
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	bpf_user_ringbuf_drain(&user_ringbuf, null_context_write, NULL, 0);
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	return 0;
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}
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static long
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null_context_read(struct bpf_dynptr *dynptr, void *context)
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{
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	__u64 id = *((__u64 *)context);
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	bpf_printk("Read id %lu\n", id);
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	return 0;
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}
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/* A callback that accesses a dynptr in a bpf_user_ringbuf_drain callback should
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 * not be able to write to that pointer.
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 */
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SEC("?raw_tp/sys_nanosleep")
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int user_ringbuf_callback_null_context_read(void *ctx)
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{
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	bpf_user_ringbuf_drain(&user_ringbuf, null_context_read, NULL, 0);
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	return 0;
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}
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static long
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try_discard_dynptr(struct bpf_dynptr *dynptr, void *context)
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{
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	bpf_ringbuf_discard_dynptr(dynptr, 0);
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	return 0;
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}
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/* A callback that accesses a dynptr in a bpf_user_ringbuf_drain callback should
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 * not be able to read past the end of the pointer.
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 */
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SEC("?raw_tp/sys_nanosleep")
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int user_ringbuf_callback_discard_dynptr(void *ctx)
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{
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	bpf_user_ringbuf_drain(&user_ringbuf, try_discard_dynptr, NULL, 0);
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	return 0;
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}
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static long
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try_submit_dynptr(struct bpf_dynptr *dynptr, void *context)
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{
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	bpf_ringbuf_submit_dynptr(dynptr, 0);
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	return 0;
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}
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/* A callback that accesses a dynptr in a bpf_user_ringbuf_drain callback should
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 * not be able to read past the end of the pointer.
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 */
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SEC("?raw_tp/sys_nanosleep")
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int user_ringbuf_callback_submit_dynptr(void *ctx)
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{
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	bpf_user_ringbuf_drain(&user_ringbuf, try_submit_dynptr, NULL, 0);
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	return 0;
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}
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static long
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invalid_drain_callback_return(struct bpf_dynptr *dynptr, void *context)
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{
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	return 2;
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}
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/* A callback that accesses a dynptr in a bpf_user_ringbuf_drain callback should
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 * not be able to write to that pointer.
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 */
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SEC("?raw_tp/sys_nanosleep")
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int user_ringbuf_callback_invalid_return(void *ctx)
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{
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	bpf_user_ringbuf_drain(&user_ringbuf, invalid_drain_callback_return, NULL, 0);
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	return 0;
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}
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