--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -1251,6 +1251,30 @@ static int check_ptr_alignment(struct bp
 	return check_generic_ptr_alignment(reg, pointer_desc, off, size, strict);
 }
 
+static int check_ctx_reg(struct bpf_verifier_env *env,
+			 const struct bpf_reg_state *reg, int regno)
+{
+	/* Access to ctx or passing it to a helper is only allowed in
+	 * its original, unmodified form.
+	 */
+
+	if (reg->off) {
+		verbose("dereference of modified ctx ptr R%d off=%d disallowed\n",
+			regno, reg->off);
+		return -EACCES;
+	}
+
+	if (!tnum_is_const(reg->var_off) || reg->var_off.value) {
+		char tn_buf[48];
+
+		tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
+		verbose("variable ctx access var_off=%s disallowed\n", tn_buf);
+		return -EACCES;
+	}
+
+	return 0;
+}
+
 /* truncate register to smaller size (in bytes)
  * must be called with size < BPF_REG_SIZE
  */
@@ -1320,22 +1344,10 @@ static int check_mem_access(struct bpf_v
 			verbose("R%d leaks addr into ctx\n", value_regno);
 			return -EACCES;
 		}
-		/* ctx accesses must be at a fixed offset, so that we can
-		 * determine what type of data were returned.
-		 */
-		if (reg->off) {
-			verbose("dereference of modified ctx ptr R%d off=%d+%d, ctx+const is allowed, ctx+const+const is not\n",
-				regno, reg->off, off - reg->off);
-			return -EACCES;
-		}
-		if (!tnum_is_const(reg->var_off) || reg->var_off.value) {
-			char tn_buf[48];
+		err = check_ctx_reg(env, reg, regno);
+		if (err < 0)
+			return err;
 
-			tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
-			verbose("variable ctx access var_off=%s off=%d size=%d",
-				tn_buf, off, size);
-			return -EACCES;
-		}
 		err = check_ctx_access(env, insn_idx, off, size, t, &reg_type);
 		if (!err && t == BPF_READ && value_regno >= 0) {
 			/* ctx access returns either a scalar, or a
@@ -1573,6 +1585,9 @@ static int check_func_arg(struct bpf_ver
 		expected_type = PTR_TO_CTX;
 		if (type != expected_type)
 			goto err_type;
+		err = check_ctx_reg(env, reg, regno);
+		if (err < 0)
+			return err;
 	} else if (arg_type == ARG_PTR_TO_MEM ||
 		   arg_type == ARG_PTR_TO_UNINIT_MEM) {
 		expected_type = PTR_TO_STACK;
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -7281,7 +7281,7 @@ static struct bpf_test tests[] = {
 				    offsetof(struct __sk_buff, mark)),
 			BPF_EXIT_INSN(),
 		},
-		.errstr = "dereference of modified ctx ptr R1 off=68+8, ctx+const is allowed, ctx+const+const is not",
+		.errstr = "dereference of modified ctx ptr",
 		.result = REJECT,
 		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
 	},
@@ -7944,6 +7944,62 @@ static struct bpf_test tests[] = {
 		.errstr = "BPF_XADD stores into R2 packet",
 		.prog_type = BPF_PROG_TYPE_XDP,
 	},
+	{
+		"pass unmodified ctx pointer to helper",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_2, 0),
+			BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
+				     BPF_FUNC_csum_update),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+		.result = ACCEPT,
+	},
+	{
+		"pass modified ctx pointer to helper, 1",
+		.insns = {
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -612),
+			BPF_MOV64_IMM(BPF_REG_2, 0),
+			BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
+				     BPF_FUNC_csum_update),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+		.result = REJECT,
+		.errstr = "dereference of modified ctx ptr",
+	},
+	{
+		"pass modified ctx pointer to helper, 2",
+		.insns = {
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -612),
+			BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
+				     BPF_FUNC_get_socket_cookie),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.result_unpriv = REJECT,
+		.result = REJECT,
+		.errstr_unpriv = "dereference of modified ctx ptr",
+		.errstr = "dereference of modified ctx ptr",
+	},
+	{
+		"pass modified ctx pointer to helper, 3",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1, 0),
+			BPF_ALU64_IMM(BPF_AND, BPF_REG_3, 4),
+			BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_3),
+			BPF_MOV64_IMM(BPF_REG_2, 0),
+			BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
+				     BPF_FUNC_csum_update),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+		.result = REJECT,
+		.errstr = "variable ctx access var_off=(0x0; 0x4)",
+	},
 };
 
 static int probe_filter_length(const struct bpf_insn *fp)
