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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>
Subject: [PATCH bpf-next v1 12/13] selftests/bpf: Add dynptr partial slot overwrite tests
Date: Tue, 18 Oct 2022 19:29:19 +0530	[thread overview]
Message-ID: <20221018135920.726360-13-memxor@gmail.com> (raw)
In-Reply-To: <20221018135920.726360-1-memxor@gmail.com>

Try creating a dynptr, then overwriting second slot with first slot of
another dynptr. Then, the first slot of first dynptr should also be
invalidated, but without our fix that does not happen. As a consequence,
the unfixed case allows passing first dynptr (as the kernel check only
checks for slot_type and then first_slot == true).

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
---
 tools/testing/selftests/bpf/verifier/dynptr.c | 58 +++++++++++++++++++
 1 file changed, 58 insertions(+)

diff --git a/tools/testing/selftests/bpf/verifier/dynptr.c b/tools/testing/selftests/bpf/verifier/dynptr.c
index 1aa7241e8a9e..8c57bc9e409f 100644
--- a/tools/testing/selftests/bpf/verifier/dynptr.c
+++ b/tools/testing/selftests/bpf/verifier/dynptr.c
@@ -122,3 +122,61 @@
 	.result = REJECT,
 	.errstr = "dynptr has to be at the constant offset",
 },
+{
+       "dynptr: partial dynptr slot invalidate",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_LD_MAP_FD(BPF_REG_6, 0),
+	BPF_LD_MAP_FD(BPF_REG_7, 0),
+	BPF_MOV64_REG(BPF_REG_1, BPF_REG_7),
+	BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+	BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0),
+	BPF_MOV64_REG(BPF_REG_3, BPF_REG_2),
+	BPF_MOV64_IMM(BPF_REG_4, 0),
+	BPF_MOV64_REG(BPF_REG_8, BPF_REG_2),
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_update_elem),
+	BPF_MOV64_REG(BPF_REG_1, BPF_REG_7),
+	BPF_MOV64_REG(BPF_REG_2, BPF_REG_8),
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
+	BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
+	BPF_EXIT_INSN(),
+	BPF_MOV64_REG(BPF_REG_7, BPF_REG_0),
+	BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
+	BPF_MOV64_IMM(BPF_REG_2, 8),
+	BPF_MOV64_IMM(BPF_REG_3, 0),
+	BPF_MOV64_REG(BPF_REG_4, BPF_REG_10),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, -24),
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_ringbuf_reserve_dynptr),
+	BPF_ST_MEM(BPF_DW, BPF_REG_10, -16, 0),
+	BPF_MOV64_REG(BPF_REG_1, BPF_REG_7),
+	BPF_MOV64_IMM(BPF_REG_2, 8),
+	BPF_MOV64_IMM(BPF_REG_3, 0),
+	BPF_MOV64_REG(BPF_REG_4, BPF_REG_10),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, -16),
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_dynptr_from_mem),
+	BPF_MOV64_REG(BPF_REG_1, BPF_REG_10),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -512),
+	BPF_MOV64_IMM(BPF_REG_2, 488),
+	BPF_MOV64_REG(BPF_REG_3, BPF_REG_10),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, -24),
+	BPF_MOV64_IMM(BPF_REG_4, 0),
+	BPF_MOV64_IMM(BPF_REG_5, 0),
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_dynptr_read),
+	BPF_MOV64_IMM(BPF_REG_8, 1),
+	BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
+	BPF_MOV64_IMM(BPF_REG_8, 0),
+	BPF_MOV64_REG(BPF_REG_1, BPF_REG_10),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -24),
+	BPF_MOV64_IMM(BPF_REG_2, 0),
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_ringbuf_discard_dynptr),
+	BPF_MOV64_REG(BPF_REG_0, BPF_REG_8),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_ringbuf = { 1 },
+	.fixup_map_hash_8b = { 3 },
+	.result_unpriv = REJECT,
+	.errstr_unpriv = "unknown func bpf_ringbuf_reserve_dynptr#198",
+	.result = REJECT,
+	.errstr = "Expected an initialized dynptr as arg #3",
+},
-- 
2.38.0


  parent reply	other threads:[~2022-10-18 14:00 UTC|newest]

Thread overview: 54+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-10-18 13:59 [PATCH bpf-next v1 00/13] Fixes for dynptr Kumar Kartikeya Dwivedi
2022-10-18 13:59 ` [PATCH bpf-next v1 01/13] bpf: Refactor ARG_PTR_TO_DYNPTR checks into process_dynptr_func Kumar Kartikeya Dwivedi
2022-10-18 19:45   ` David Vernet
2022-10-19  6:04     ` Kumar Kartikeya Dwivedi
2022-10-19 15:26       ` David Vernet
2022-10-19 22:59   ` Joanne Koong
2022-10-20  0:55     ` Kumar Kartikeya Dwivedi
2022-10-18 13:59 ` [PATCH bpf-next v1 02/13] bpf: Rework process_dynptr_func Kumar Kartikeya Dwivedi
2022-10-18 23:16   ` David Vernet
2022-10-19  6:18     ` Kumar Kartikeya Dwivedi
2022-10-19 16:05       ` David Vernet
2022-10-20  1:09         ` Kumar Kartikeya Dwivedi
2022-10-18 13:59 ` [PATCH bpf-next v1 03/13] bpf: Rename confusingly named RET_PTR_TO_ALLOC_MEM Kumar Kartikeya Dwivedi
2022-10-18 21:38   ` sdf
2022-10-19  6:19     ` Kumar Kartikeya Dwivedi
2022-11-07 22:35   ` Joanne Koong
2022-11-07 23:12     ` Kumar Kartikeya Dwivedi
2022-10-18 13:59 ` [PATCH bpf-next v1 04/13] bpf: Rework check_func_arg_reg_off Kumar Kartikeya Dwivedi
2022-10-18 21:55   ` sdf
2022-10-19  6:24     ` Kumar Kartikeya Dwivedi
2022-11-07 23:17   ` Joanne Koong
2022-11-08 18:22     ` Kumar Kartikeya Dwivedi
2022-10-18 13:59 ` [PATCH bpf-next v1 05/13] bpf: Fix state pruning for STACK_DYNPTR stack slots Kumar Kartikeya Dwivedi
2022-11-08 20:22   ` Joanne Koong
2022-11-09 18:39     ` Kumar Kartikeya Dwivedi
2022-11-10  0:41       ` Joanne Koong
2022-10-18 13:59 ` [PATCH bpf-next v1 06/13] bpf: Fix missing var_off check for ARG_PTR_TO_DYNPTR Kumar Kartikeya Dwivedi
2022-10-19 18:52   ` Alexei Starovoitov
2022-10-20  1:04     ` Kumar Kartikeya Dwivedi
2022-10-20  2:13       ` Alexei Starovoitov
2022-10-20  2:40         ` Kumar Kartikeya Dwivedi
2022-10-20  2:56           ` Alexei Starovoitov
2022-10-20  3:23             ` Kumar Kartikeya Dwivedi
2022-10-21  0:46               ` Alexei Starovoitov
2022-10-21  1:53                 ` Kumar Kartikeya Dwivedi
2022-10-18 13:59 ` [PATCH bpf-next v1 07/13] bpf: Fix partial dynptr stack slot reads/writes Kumar Kartikeya Dwivedi
2022-10-21 22:50   ` Joanne Koong
2022-10-21 22:57     ` Joanne Koong
2022-10-22  4:08     ` Kumar Kartikeya Dwivedi
2022-11-03 14:07       ` Joanne Koong
2022-11-04 22:14         ` Andrii Nakryiko
2022-11-04 23:02           ` Kumar Kartikeya Dwivedi
2022-11-04 23:08             ` Andrii Nakryiko
2022-10-18 13:59 ` [PATCH bpf-next v1 08/13] bpf: Use memmove for bpf_dynptr_{read,write} Kumar Kartikeya Dwivedi
2022-10-21 18:12   ` Joanne Koong
2022-10-18 13:59 ` [PATCH bpf-next v1 09/13] selftests/bpf: Add test for dynptr reinit in user_ringbuf callback Kumar Kartikeya Dwivedi
2022-10-19 16:59   ` David Vernet
2022-10-18 13:59 ` [PATCH bpf-next v1 10/13] selftests/bpf: Add dynptr pruning tests Kumar Kartikeya Dwivedi
2022-10-18 13:59 ` [PATCH bpf-next v1 11/13] selftests/bpf: Add dynptr var_off tests Kumar Kartikeya Dwivedi
2022-10-18 13:59 ` Kumar Kartikeya Dwivedi [this message]
2022-10-18 13:59 ` [PATCH bpf-next v1 13/13] selftests/bpf: Add dynptr helper tests Kumar Kartikeya Dwivedi
2023-10-31  7:05 ` CVE-2023-39191 - Dynptr fixes - reg Nandhini Rengaraj
2023-10-31  7:13   ` Greg KH
2023-10-31  7:57   ` Shung-Hsi Yu

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