From: Kumar Kartikeya Dwivedi <memxor@gmail.com>
To: bpf@vger.kernel.org
Cc: Alexei Starovoitov <ast@kernel.org>,
Andrii Nakryiko <andrii@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Martin KaFai Lau <martin.lau@kernel.org>,
Joanne Koong <joannelkoong@gmail.com>,
David Vernet <void@manifault.com>,
Eduard Zingerman <eddyz87@gmail.com>
Subject: [PATCH bpf-next v1 8/8] selftests/bpf: Add dynptr helper tests
Date: Sun, 1 Jan 2023 14:04:02 +0530 [thread overview]
Message-ID: <20230101083403.332783-9-memxor@gmail.com> (raw)
In-Reply-To: <20230101083403.332783-1-memxor@gmail.com>
First test that we allow overwriting dynptr slots and reinitializing
them. Next, test that MEM_UNINIT doesn't allow writing dynptr stack
slots.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
---
.../testing/selftests/bpf/progs/dynptr_fail.c | 62 +++++++++++++++++++
1 file changed, 62 insertions(+)
diff --git a/tools/testing/selftests/bpf/progs/dynptr_fail.c b/tools/testing/selftests/bpf/progs/dynptr_fail.c
index 32df3647b794..73ae93dedaba 100644
--- a/tools/testing/selftests/bpf/progs/dynptr_fail.c
+++ b/tools/testing/selftests/bpf/progs/dynptr_fail.c
@@ -653,3 +653,65 @@ int dynptr_from_mem_invalid_api(void *ctx)
return 0;
}
+
+SEC("?raw_tp")
+__success
+int dynptr_overwrite_unref(void *ctx)
+{
+ struct bpf_dynptr ptr;
+
+ get_map_val_dynptr(&ptr);
+ get_map_val_dynptr(&ptr);
+ get_map_val_dynptr(&ptr);
+
+ return 0;
+}
+
+SEC("?raw_tp")
+__failure __msg("Unreleased reference")
+int dynptr_overwrite_ref(void *ctx)
+{
+ struct bpf_dynptr ptr;
+
+ bpf_ringbuf_reserve_dynptr(&ringbuf, 64, 0, &ptr);
+ if (get_map_val_dynptr(&ptr))
+ bpf_ringbuf_discard_dynptr(&ptr, 0);
+ return 0;
+}
+
+/* Reject writes to dynptr slot from bpf_dynptr_read */
+SEC("?raw_tp")
+__failure __msg("potential write to dynptr at off=-16")
+int dynptr_read_into_slot(void *ctx)
+{
+ union {
+ struct {
+ char _pad[48];
+ struct bpf_dynptr ptr;
+ };
+ char buf[64];
+ } data;
+
+ bpf_ringbuf_reserve_dynptr(&ringbuf, 64, 0, &data.ptr);
+ /* this should fail */
+ bpf_dynptr_read(data.buf, sizeof(data.buf), &data.ptr, 0, 0);
+
+ return 0;
+}
+
+/* Reject writes to dynptr slot for uninit arg */
+SEC("?raw_tp")
+__failure __msg("potential write to dynptr at off=-16")
+int uninit_write_into_slot(void *ctx)
+{
+ struct {
+ char buf[64];
+ struct bpf_dynptr ptr;
+ } data;
+
+ bpf_ringbuf_reserve_dynptr(&ringbuf, 80, 0, &data.ptr);
+ /* this should fail */
+ bpf_get_current_comm(data.buf, 80);
+
+ return 0;
+}
--
2.39.0
next prev parent reply other threads:[~2023-01-01 8:34 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-01 8:33 [PATCH bpf-next v1 0/8] Dynptr fixes Kumar Kartikeya Dwivedi
2023-01-01 8:33 ` [PATCH bpf-next v1 1/8] bpf: Fix state pruning for STACK_DYNPTR stack slots Kumar Kartikeya Dwivedi
2023-01-02 19:28 ` Eduard Zingerman
2023-01-09 10:59 ` Kumar Kartikeya Dwivedi
2023-01-04 22:24 ` Andrii Nakryiko
2023-01-09 11:05 ` Kumar Kartikeya Dwivedi
2023-01-12 0:47 ` Andrii Nakryiko
2023-01-06 0:18 ` Joanne Koong
2023-01-09 11:17 ` Kumar Kartikeya Dwivedi
2023-01-01 8:33 ` [PATCH bpf-next v1 2/8] bpf: Fix missing var_off check for ARG_PTR_TO_DYNPTR Kumar Kartikeya Dwivedi
2023-01-04 22:32 ` Andrii Nakryiko
2023-01-09 11:18 ` Kumar Kartikeya Dwivedi
2023-01-06 0:57 ` Joanne Koong
2023-01-06 17:56 ` Joanne Koong
2023-01-09 11:21 ` Kumar Kartikeya Dwivedi
2023-01-01 8:33 ` [PATCH bpf-next v1 3/8] bpf: Fix partial dynptr stack slot reads/writes Kumar Kartikeya Dwivedi
2023-01-04 22:42 ` Andrii Nakryiko
2023-01-09 11:26 ` Kumar Kartikeya Dwivedi
2023-01-05 3:06 ` Alexei Starovoitov
2023-01-09 11:52 ` Kumar Kartikeya Dwivedi
2023-01-10 2:19 ` Alexei Starovoitov
2023-01-06 19:16 ` Joanne Koong
2023-01-06 19:31 ` Joanne Koong
2023-01-09 11:30 ` Kumar Kartikeya Dwivedi
2023-01-12 18:51 ` Joanne Koong
2023-01-01 8:33 ` [PATCH bpf-next v1 4/8] bpf: Allow reinitializing unreferenced dynptr stack slots Kumar Kartikeya Dwivedi
2023-01-04 22:44 ` Andrii Nakryiko
2023-01-06 19:33 ` Joanne Koong
2023-01-09 11:40 ` Kumar Kartikeya Dwivedi
2023-01-01 8:33 ` [PATCH bpf-next v1 5/8] selftests/bpf: Add dynptr pruning tests Kumar Kartikeya Dwivedi
2023-01-04 22:49 ` Andrii Nakryiko
2023-01-09 11:44 ` Kumar Kartikeya Dwivedi
2023-01-01 8:34 ` [PATCH bpf-next v1 6/8] selftests/bpf: Add dynptr var_off tests Kumar Kartikeya Dwivedi
2023-01-01 8:34 ` [PATCH bpf-next v1 7/8] selftests/bpf: Add dynptr partial slot overwrite tests Kumar Kartikeya Dwivedi
2023-01-01 8:34 ` Kumar Kartikeya Dwivedi [this message]
2023-01-04 22:51 ` [PATCH bpf-next v1 0/8] Dynptr fixes Andrii Nakryiko
2023-01-12 1:08 ` Kumar Kartikeya Dwivedi
2023-01-13 22:31 ` Andrii Nakryiko
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