1 files changed, 121 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/verifier_netfilter_ctx.c b/tools/testing/selftests/bpf/progs/verifier_netfilter_ctx.c
new file mode 100644
index 000000000000..65bba330e7e5
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/verifier_netfilter_ctx.c
@@ -0,0 +1,121 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "vmlinux.h"
+
+#include "bpf_misc.h"
+
+#include <bpf/bpf_endian.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_helpers.h>
+
+SEC("netfilter")
+__description("netfilter invalid context access, size too short")
+__failure __msg("invalid bpf_context access")
+__naked void with_invalid_ctx_access_test1(void)
+{
+	asm volatile ("					\
+	r2 = *(u8*)(r1 + %[__bpf_nf_ctx_state]);	\
+	r0 = 0;						\
+	exit;						\
+"	:
+	: __imm_const(__bpf_nf_ctx_state, offsetof(struct bpf_nf_ctx, state))
+	: __clobber_all);
+}
+
+SEC("netfilter")
+__description("netfilter invalid context access, size too short")
+__failure __msg("invalid bpf_context access")
+__naked void with_invalid_ctx_access_test2(void)
+{
+	asm volatile ("					\
+	r2 = *(u16*)(r1 + %[__bpf_nf_ctx_skb]);	\
+	r0 = 0;						\
+	exit;						\
+"	:
+	: __imm_const(__bpf_nf_ctx_skb, offsetof(struct bpf_nf_ctx, skb))
+	: __clobber_all);
+}
+
+SEC("netfilter")
+__description("netfilter invalid context access, past end of ctx")
+__failure __msg("invalid bpf_context access")
+__naked void with_invalid_ctx_access_test3(void)
+{
+	asm volatile ("					\
+	r2 = *(u64*)(r1 + %[__bpf_nf_ctx_size]);	\
+	r0 = 0;						\
+	exit;						\
+"	:
+	: __imm_const(__bpf_nf_ctx_size, sizeof(struct bpf_nf_ctx))
+	: __clobber_all);
+}
+
+SEC("netfilter")
+__description("netfilter invalid context, write")
+__failure __msg("invalid bpf_context access")
+__naked void with_invalid_ctx_access_test4(void)
+{
+	asm volatile ("					\
+	r2 = r1;					\
+	*(u64*)(r2 + 0) = r1;				\
+	r0 = 1;						\
+	exit;						\
+"	:
+	: __imm_const(__bpf_nf_ctx_skb, offsetof(struct bpf_nf_ctx, skb))
+	: __clobber_all);
+}
+
+#define NF_DROP 0
+#define NF_ACCEPT 1
+
+SEC("netfilter")
+__description("netfilter valid context read and invalid write")
+__failure __msg("only read is supported")
+int with_invalid_ctx_access_test5(struct bpf_nf_ctx *ctx)
+{
+	struct nf_hook_state *state = (void *)ctx->state;
+
+	state->sk = NULL;
+	return NF_ACCEPT;
+}
+
+extern int bpf_dynptr_from_skb(struct sk_buff *skb, __u64 flags,
+                               struct bpf_dynptr *ptr__uninit) __ksym;
+extern void *bpf_dynptr_slice(const struct bpf_dynptr *ptr, uint32_t offset,
+                                   void *buffer, uint32_t buffer__sz) __ksym;
+
+SEC("netfilter")
+__description("netfilter test prog with skb and state read access")
+__success __failure_unpriv
+__retval(0)
+int with_valid_ctx_access_test6(struct bpf_nf_ctx *ctx)
+{
+	const struct nf_hook_state *state = ctx->state;
+	struct sk_buff *skb = ctx->skb;
+	const struct iphdr *iph;
+	const struct tcphdr *th;
+	u8 buffer_iph[20] = {};
+	u8 buffer_th[40] = {};
+	struct bpf_dynptr ptr;
+	uint8_t ihl;
+
+	if (skb->len <= 20 || bpf_dynptr_from_skb(skb, 0, &ptr))
+		return NF_ACCEPT;
+
+	iph = bpf_dynptr_slice(&ptr, 0, buffer_iph, sizeof(buffer_iph));
+	if (!iph)
+		return NF_ACCEPT;
+
+	if (state->pf != 2)
+		return NF_ACCEPT;
+
+	ihl = iph->ihl << 2;
+
+	th = bpf_dynptr_slice(&ptr, ihl, buffer_th, sizeof(buffer_th));
+	if (!th)
+		return NF_ACCEPT;
+
+	return th->dest == bpf_htons(22) ? NF_ACCEPT : NF_DROP;
+}
+
+char _license[] SEC("license") = "GPL";