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// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2026 Qi Tang */
#include <vmlinux.h>
#include <bpf/bpf_helpers.h>
#include "bpf_misc.h"
char _license[] SEC("license") = "GPL";
/* Verify that the verifier rejects direct access to nullable PTR_TO_BUF. */
SEC("iter/bpf_map_elem")
__failure __msg("invalid mem access")
int iter_buf_null_deref(struct bpf_iter__bpf_map_elem *ctx)
{
/*
* ctx->key is PTR_TO_BUF | PTR_MAYBE_NULL | MEM_RDONLY.
* Direct access without null check must be rejected.
*/
volatile __u32 v = *(__u32 *)ctx->key;
(void)v;
return 0;
}
/* Verify that access after a null check is still accepted. */
SEC("iter/bpf_map_elem")
__success
int iter_buf_null_check_ok(struct bpf_iter__bpf_map_elem *ctx)
{
__u32 *key = ctx->key;
if (!key)
return 0;
volatile __u32 v = *key;
(void)v;
return 0;
}
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