From e435b043d89a267bd6eb3d5650d2319805d7924a Mon Sep 17 00:00:00 2001
From: Tengda Wu <wutengda@huaweicloud.com>
Date: Thu, 11 Jul 2024 22:58:19 +0800
Subject: [PATCH] selftests/bpf: Test for null-pointer-deref bugfix in
resolve_prog_type()
This test verifies that resolve_prog_type() works as expected when
`attach_prog_fd` is not passed in.
`prog->aux->dst_prog` in resolve_prog_type() is assigned by
`attach_prog_fd`, and would be NULL if `attach_prog_fd` is not provided.
Loading EXT prog with bpf_dynptr_from_skb() kfunc call in this way will
lead to null-pointer-deref.
Verify that the null-pointer-deref bug in resolve_prog_type() is fixed.
Signed-off-by: Tengda Wu <wutengda@huaweicloud.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240711145819.254178-3-wutengda@huaweicloud.com
---
tools/testing/selftests/bpf/verifier/calls.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/tools/testing/selftests/bpf/verifier/calls.c b/tools/testing/selftests/bpf/verifier/calls.c
index d76ef20188592..d0cdd156cd555 100644
--- a/tools/testing/selftests/bpf/verifier/calls.c
+++ b/tools/testing/selftests/bpf/verifier/calls.c
@@ -275,6 +275,19 @@
.result_unpriv = REJECT,
.result = ACCEPT,
},
+{
+ "calls: invalid kfunc call: must provide (attach_prog_fd, btf_id) pair when freplace",
+ .insns = {
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .prog_type = BPF_PROG_TYPE_EXT,
+ .result = REJECT,
+ .errstr = "Tracing programs must provide btf_id",
+ .fixup_kfunc_btf_id = {
+ { "bpf_dynptr_from_skb", 0 },
+ },
+},
{
"calls: basic sanity",
.insns = {
--
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