From: Alexei Starovoitov <ast@kernel.org>
Date: Mon, 1 Nov 2021 15:21:53 -0700
Subject: selftests/bpf: Add a testcase for 64-bit bounds propagation issue.
Patch-mainline: v5.16-rc1
Git-commit: 0869e5078afbd1b22c20832b391b2d85291bc0a8
References: jsc#PED-1377
./test_progs-no_alu32 -vv -t twfw
Before the 64-bit_into_32-bit fix:
19: (25) if r1 > 0x3f goto pc+6
R1_w=inv(id=0,umax_value=63,var_off=(0x0; 0xff),s32_max_value=255,u32_max_value=255)
and eventually:
invalid access to map value, value_size=8 off=7 size=8
R6 max value is outside of the allowed memory range
libbpf: failed to load object 'no_alu32/twfw.o'
After the fix:
19: (25) if r1 > 0x3f goto pc+6
R1_w=inv(id=0,umax_value=63,var_off=(0x0; 0x3f))
verif_twfw:OK
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20211101222153.78759-3-alexei.starovoitov@gmail.com
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
---
tools/testing/selftests/bpf/prog_tests/bpf_verif_scale.c | 5 +
tools/testing/selftests/bpf/progs/twfw.c | 58 +++++++++++++++
2 files changed, 63 insertions(+)
create mode 100644 tools/testing/selftests/bpf/progs/twfw.c
--- a/tools/testing/selftests/bpf/prog_tests/bpf_verif_scale.c
+++ b/tools/testing/selftests/bpf/prog_tests/bpf_verif_scale.c
@@ -202,3 +202,8 @@ void test_verif_scale_seg6_loop()
{
scale_test("test_seg6_loop.o", BPF_PROG_TYPE_LWT_SEG6LOCAL, false);
}
+
+void test_verif_twfw()
+{
+ scale_test("twfw.o", BPF_PROG_TYPE_CGROUP_SKB, false);
+}
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/twfw.c
@@ -0,0 +1,58 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2021 Facebook */
+#include <linux/types.h>
+#include <bpf/bpf_helpers.h>
+#include <linux/bpf.h>
+#include <stdint.h>
+
+#define TWFW_MAX_TIERS (64)
+/*
+ * load is successful
+ * #define TWFW_MAX_TIERS (64u)$
+ */
+
+struct twfw_tier_value {
+ unsigned long mask[1];
+};
+
+struct rule {
+ uint8_t seqnum;
+};
+
+struct rules_map {
+ __uint(type, BPF_MAP_TYPE_ARRAY);
+ __type(key, __u32);
+ __type(value, struct rule);
+ __uint(max_entries, 1);
+};
+
+struct tiers_map {
+ __uint(type, BPF_MAP_TYPE_ARRAY);
+ __type(key, __u32);
+ __type(value, struct twfw_tier_value);
+ __uint(max_entries, 1);
+};
+
+struct rules_map rules SEC(".maps");
+struct tiers_map tiers SEC(".maps");
+
+SEC("cgroup_skb/ingress")
+int twfw_verifier(struct __sk_buff* skb)
+{
+ const uint32_t key = 0;
+ const struct twfw_tier_value* tier = bpf_map_lookup_elem(&tiers, &key);
+ if (!tier)
+ return 1;
+
+ struct rule* rule = bpf_map_lookup_elem(&rules, &key);
+ if (!rule)
+ return 1;
+
+ if (rule && rule->seqnum < TWFW_MAX_TIERS) {
+ /* rule->seqnum / 64 should always be 0 */
+ unsigned long mask = tier->mask[rule->seqnum / 64];
+ if (mask)
+ return 0;
+ }
+ return 1;
+}