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From:   Hao Sun <sunhao.th@gmail.com>
To:     bpf@vger.kernel.org
Cc:     ast@kernel.org, daniel@iogearbox.net, john.fastabend@gmail.com,
        andrii@kernel.org, martin.lau@linux.dev, song@kernel.org,
        yhs@fb.com, kpsingh@kernel.org, sdf@google.com, haoluo@google.com,
        jolsa@kernel.org, davem@davemloft.net,
        linux-kernel@vger.kernel.org, Hao Sun <sunhao.th@gmail.com>
Subject: [PATCH bpf-next v2 3/3] selftests/bpf: Add tests for LDX/STX/ST sanitize
Date:   Fri, 25 Nov 2022 14:36:30 +0800
Message-Id: <20221125063630.536657-4-sunhao.th@gmail.com>
In-Reply-To: <20221125063630.536657-1-sunhao.th@gmail.com>
References: <20221125063630.536657-1-sunhao.th@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Add tests for LDX/STX/ST instrumentation in each possible case.
Four cases for STX/ST, include dst_reg equals to R0, R1, R10,
other regs, respectively, ten cases for LDX. All new/existing
selftests can pass.

A slab-out-of-bounds read report is also availble, which is
achieved by exploiting CVE-2022-23222 and can be reproduced
in Linux v5.10: https://pastebin.com/raw/Ee1Cw492.

Signed-off-by: Hao Sun <sunhao.th@gmail.com>
---
 .../selftests/bpf/verifier/sanitize_st_ldx.c  | 362 ++++++++++++++++++
 1 file changed, 362 insertions(+)
 create mode 100644 tools/testing/selftests/bpf/verifier/sanitize_st_ldx.c

diff --git a/tools/testing/selftests/bpf/verifier/sanitize_st_ldx.c b/tools/testing/selftests/bpf/verifier/sanitize_st_ldx.c
new file mode 100644
index 000000000000..1db0d1794f29
--- /dev/null
+++ b/tools/testing/selftests/bpf/verifier/sanitize_st_ldx.c
@@ -0,0 +1,362 @@
+#ifdef CONFIG_BPF_PROG_KASAN
+
+#define __BACKUP_REG(n) \
+	BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_##n, INSN_OFF_MASK)
+#define BACKUP_SCRATCH_REGS                                                 \
+	__BACKUP_REG(1), __BACKUP_REG(2), __BACKUP_REG(3), __BACKUP_REG(4), \
+		__BACKUP_REG(5)
+
+#define __RESTORE_REG(n) \
+	BPF_LDX_MEM(BPF_DW, BPF_REG_##n, BPF_REG_10, INSN_OFF_MASK)
+#define RESTORE_SCRATCH_REGS                                  \
+	__RESTORE_REG(1), __RESTORE_REG(2), __RESTORE_REG(3), \
+		__RESTORE_REG(4), __RESTORE_REG(5)
+
+{
+	"sanitize stx: dst is R1",
+	.insns = {
+	BPF_MOV64_REG(BPF_REG_1, BPF_REG_10),
+	BPF_ST_MEM(BPF_DW, BPF_REG_1, -8, 1),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 1, 1),
+	BPF_MOV64_IMM(BPF_REG_0, 2),
+	BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+	.retval = 1,
+	.expected_insns = {
+	BPF_MOV64_REG(MAX_BPF_REG, BPF_REG_0),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -8),
+	BACKUP_SCRATCH_REGS,
+	BPF_EMIT_CALL(INSN_IMM_MASK),
+	RESTORE_SCRATCH_REGS,
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+	BPF_MOV64_REG(BPF_REG_0, MAX_BPF_REG),
+	BPF_ST_MEM(BPF_DW, BPF_REG_1, -8, 1),
+	},
+},
+{
+	"sanitize stx: dst is R0",
+	.insns = {
+	BPF_MOV64_REG(BPF_REG_0, BPF_REG_10),
+	BPF_ST_MEM(BPF_DW, BPF_REG_0, -8, 1),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, -8),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 1, 2),
+	BPF_MOV64_IMM(BPF_REG_0, 2),
+	BPF_EXIT_INSN(),
+	BPF_MOV64_REG(BPF_REG_0, BPF_REG_1),
+	BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+	.retval = 1,
+	.expected_insns = {
+	BPF_MOV64_REG(MAX_BPF_REG, BPF_REG_1),
+	BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -8),
+	BACKUP_SCRATCH_REGS,
+	BPF_EMIT_CALL(INSN_IMM_MASK),
+	RESTORE_SCRATCH_REGS,
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+	BPF_MOV64_REG(BPF_REG_0, BPF_REG_1),
+	BPF_MOV64_REG(BPF_REG_1, MAX_BPF_REG),
+	BPF_ST_MEM(BPF_DW, BPF_REG_0, -8, 1),
+	},
+},
+{
+	"sanitize stx: dst is R10",
+	.insns = {
+	BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 1),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_10, -8),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 1, 1),
+	BPF_MOV64_IMM(BPF_REG_0, 2),
+	BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+	.retval = 1,
+	.unexpected_insns = {
+	BPF_EMIT_CALL(INSN_IMM_MASK),
+	},
+},
+{
+	"sanitize stx: dst is other regs",
+	.insns = {
+	BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+	BPF_ST_MEM(BPF_DW, BPF_REG_2, -8, 1),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_2, -8),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 1, 1),
+	BPF_MOV64_IMM(BPF_REG_0, 2),
+	BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+	.retval = 1,
+	.expected_insns = {
+	BPF_MOV64_REG(MAX_BPF_REG, BPF_REG_1),
+	BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+	BPF_MOV64_REG(BPF_REG_2, BPF_REG_0),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -8),
+	BACKUP_SCRATCH_REGS,
+	BPF_EMIT_CALL(INSN_IMM_MASK),
+	RESTORE_SCRATCH_REGS,
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+	BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),
+	BPF_MOV64_REG(BPF_REG_2, BPF_REG_1),
+	BPF_MOV64_REG(BPF_REG_1, MAX_BPF_REG),
+	BPF_ST_MEM(BPF_DW, BPF_REG_2, -8, 1),
+	},
+},
+{
+	"sanitize ldx: src is R1, dst is R0",
+	.insns = {
+	BPF_MOV64_REG(BPF_REG_1, BPF_REG_10),
+	BPF_ST_MEM(BPF_DW, BPF_REG_1, -8, 1),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 1, 1),
+	BPF_MOV64_IMM(BPF_REG_0, 2),
+	BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+	.retval = 1,
+	.expected_insns = {
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -8),
+	BACKUP_SCRATCH_REGS,
+	BPF_EMIT_CALL(INSN_IMM_MASK),
+	RESTORE_SCRATCH_REGS,
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8),
+	},
+},
+{
+	"sanitize ldx: src is R1, dst is R1",
+	.insns = {
+	BPF_MOV64_REG(BPF_REG_1, BPF_REG_10),
+	BPF_ST_MEM(BPF_DW, BPF_REG_1, -8, 1),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_1, -8),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 1, 2),
+	BPF_MOV64_IMM(BPF_REG_0, 2),
+	BPF_EXIT_INSN(),
+	BPF_MOV64_REG(BPF_REG_0, BPF_REG_1),
+	BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+	.retval = 1,
+	.expected_insns = {
+	BPF_MOV64_REG(MAX_BPF_REG, BPF_REG_0),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -8),
+	BACKUP_SCRATCH_REGS,
+	BPF_EMIT_CALL(INSN_IMM_MASK),
+	RESTORE_SCRATCH_REGS,
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+	BPF_MOV64_REG(BPF_REG_0, MAX_BPF_REG),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_1, -8),
+	},
+},
+{
+	"sanitize ldx: src is R1, dst is other regs",
+	.insns = {
+	BPF_MOV64_REG(BPF_REG_1, BPF_REG_10),
+	BPF_ST_MEM(BPF_DW, BPF_REG_1, -8, 1),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_2, BPF_REG_1, -8),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_2, 1, 2),
+	BPF_MOV64_IMM(BPF_REG_0, 2),
+	BPF_EXIT_INSN(),
+	BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),
+	BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+	.retval = 1,
+	.expected_insns = {
+	BPF_MOV64_REG(MAX_BPF_REG, BPF_REG_0),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -8),
+	BACKUP_SCRATCH_REGS,
+	BPF_EMIT_CALL(INSN_IMM_MASK),
+	RESTORE_SCRATCH_REGS,
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+	BPF_MOV64_REG(BPF_REG_0, MAX_BPF_REG),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_2, BPF_REG_1, -8),
+	},
+},
+{
+	"sanitize ldx: src is R0, dst is R1",
+	.insns = {
+	BPF_MOV64_REG(BPF_REG_0, BPF_REG_10),
+	BPF_ST_MEM(BPF_DW, BPF_REG_0, -8, 1),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, -8),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 1, 2),
+	BPF_MOV64_IMM(BPF_REG_0, 2),
+	BPF_EXIT_INSN(),
+	BPF_MOV64_REG(BPF_REG_0, BPF_REG_1),
+	BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+	.retval = 1,
+	.expected_insns = {
+	BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -8),
+	BACKUP_SCRATCH_REGS,
+	BPF_EMIT_CALL(INSN_IMM_MASK),
+	RESTORE_SCRATCH_REGS,
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+	BPF_MOV64_REG(BPF_REG_0, BPF_REG_1),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, -8),
+	},
+},
+{
+	"sanitize ldx: src is R0, dst is R0",
+	.insns = {
+	BPF_MOV64_REG(BPF_REG_0, BPF_REG_10),
+	BPF_ST_MEM(BPF_DW, BPF_REG_0, -8, 1),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_0, -8),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 1, 1),
+	BPF_MOV64_IMM(BPF_REG_0, 2),
+	BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+	.retval = 1,
+	.expected_insns = {
+	BPF_MOV64_REG(MAX_BPF_REG, BPF_REG_1),
+	BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -8),
+	BACKUP_SCRATCH_REGS,
+	BPF_EMIT_CALL(INSN_IMM_MASK),
+	RESTORE_SCRATCH_REGS,
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+	BPF_MOV64_REG(BPF_REG_0, BPF_REG_1),
+	BPF_MOV64_REG(BPF_REG_1, MAX_BPF_REG),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_0, -8),
+	},
+},
+{
+	"sanitize ldx: src is R0, dst is other regs",
+	.insns = {
+	BPF_MOV64_REG(BPF_REG_0, BPF_REG_10),
+	BPF_ST_MEM(BPF_DW, BPF_REG_0, -8, 1),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_2, BPF_REG_0, -8),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_2, 1, 2),
+	BPF_MOV64_IMM(BPF_REG_0, 2),
+	BPF_EXIT_INSN(),
+	BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),
+	BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+	.retval = 1,
+	.expected_insns = {
+	BPF_MOV64_REG(MAX_BPF_REG, BPF_REG_1),
+	BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -8),
+	BACKUP_SCRATCH_REGS,
+	BPF_EMIT_CALL(INSN_IMM_MASK),
+	RESTORE_SCRATCH_REGS,
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+	BPF_MOV64_REG(BPF_REG_0, BPF_REG_1),
+	BPF_MOV64_REG(BPF_REG_1, MAX_BPF_REG),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_2, BPF_REG_0, -8),
+	},
+},
+{
+	"sanitize ldx: src is other regs, dst is R0",
+	.insns = {
+	BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+	BPF_ST_MEM(BPF_DW, BPF_REG_2, -8, 1),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_2, -8),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 1, 1),
+	BPF_MOV64_IMM(BPF_REG_0, 2),
+	BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+	.retval = 1,
+	.expected_insns = {
+	BPF_MOV64_REG(MAX_BPF_REG, BPF_REG_1),
+	BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -8),
+	BACKUP_SCRATCH_REGS,
+	BPF_EMIT_CALL(INSN_IMM_MASK),
+	RESTORE_SCRATCH_REGS,
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+	BPF_MOV64_REG(BPF_REG_1, MAX_BPF_REG),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_2, -8),
+	},
+},
+{
+	"sanitize ldx: src is other regs, dst is R1",
+	.insns = {
+	BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+	BPF_ST_MEM(BPF_DW, BPF_REG_2, -8, 1),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_2, -8),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 1, 2),
+	BPF_MOV64_IMM(BPF_REG_0, 2),
+	BPF_EXIT_INSN(),
+	BPF_MOV64_REG(BPF_REG_0, BPF_REG_1),
+	BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+	.retval = 1,
+	.expected_insns = {
+	BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+	BPF_MOV64_REG(MAX_BPF_REG, BPF_REG_0),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -8),
+	BACKUP_SCRATCH_REGS,
+	BPF_EMIT_CALL(INSN_IMM_MASK),
+	RESTORE_SCRATCH_REGS,
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+	BPF_MOV64_REG(BPF_REG_0, MAX_BPF_REG),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_2, -8),
+	},
+},
+{
+	"sanitize ldx: src is other regs, dst is self",
+	.insns = {
+	BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+	BPF_ST_MEM(BPF_DW, BPF_REG_2, -8, 1),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_2, BPF_REG_2, -8),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_2, 1, 2),
+	BPF_MOV64_IMM(BPF_REG_0, 2),
+	BPF_EXIT_INSN(),
+	BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),
+	BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+	.retval = 1,
+	.expected_insns = {
+	BPF_MOV64_REG(MAX_BPF_REG, BPF_REG_1),
+	BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+	BPF_MOV64_REG(BPF_REG_2, BPF_REG_0),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -8),
+	BACKUP_SCRATCH_REGS,
+	BPF_EMIT_CALL(INSN_IMM_MASK),
+	RESTORE_SCRATCH_REGS,
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+	BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),
+	BPF_MOV64_REG(BPF_REG_2, BPF_REG_1),
+	BPF_MOV64_REG(BPF_REG_1, MAX_BPF_REG),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_2, BPF_REG_2, -8),
+	},
+},
+{
+	"sanitize ldx: src is other regs, dst is other regs",
+	.insns = {
+	BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+	BPF_ST_MEM(BPF_DW, BPF_REG_2, -8, 1),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_3, BPF_REG_2, -8),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_3, 1, 2),
+	BPF_MOV64_IMM(BPF_REG_0, 2),
+	BPF_EXIT_INSN(),
+	BPF_MOV64_REG(BPF_REG_0, BPF_REG_3),
+	BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+	.retval = 1,
+	.expected_insns = {
+	BPF_MOV64_REG(MAX_BPF_REG, BPF_REG_1),
+	BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+	BPF_MOV64_REG(BPF_REG_3, BPF_REG_0),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -8),
+	BACKUP_SCRATCH_REGS,
+	BPF_EMIT_CALL(INSN_IMM_MASK),
+	RESTORE_SCRATCH_REGS,
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+	BPF_MOV64_REG(BPF_REG_0, BPF_REG_3),
+	BPF_MOV64_REG(BPF_REG_1, MAX_BPF_REG),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_3, BPF_REG_2, -8),
+	},
+},
+#endif /* CONFIG_BPF_PROG_KASAN */
-- 
2.38.1