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linux/tools/testing/selftests/bpf/verifier/var_off.c

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selftests: bpf: break up test_verifier Break up the first 10 kLoC of test verifier test cases out into smaller files. Looks like git line counting gets a little flismy above 16 bit integers, so we need two commits to break up test_verifier. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Acked-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-01-25 15:24:43 -08:00
{
"variable-offset ctx access",
.insns = {
/* Get an unknown value */
BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, 0),
/* Make it small and 4-byte aligned */
BPF_ALU64_IMM(BPF_AND, BPF_REG_2, 4),
/* add it to skb. We now have either &skb->len or
* &skb->pkt_type, but we don't know which
*/
BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_2),
/* dereference it */
BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1, 0),
BPF_EXIT_INSN(),
},
.errstr = "variable ctx access var_off=(0x0; 0x4)",
.result = REJECT,
.prog_type = BPF_PROG_TYPE_LWT_IN,
},
{
selftest/bpf: Adjust expected verifier errors The verifier errors around stack accesses have changed slightly in the previous commit (generally for the better). Signed-off-by: Andrei Matei <andreimatei1@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210207011027.676572-3-andreimatei1@gmail.com
2021-02-06 20:10:25 -05:00
"variable-offset stack read, priv vs unpriv",
selftests: bpf: break up test_verifier Break up the first 10 kLoC of test verifier test cases out into smaller files. Looks like git line counting gets a little flismy above 16 bit integers, so we need two commits to break up test_verifier. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Acked-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-01-25 15:24:43 -08:00
.insns = {
/* Fill the top 8 bytes of the stack */
BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
/* Get an unknown value */
BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, 0),
/* Make it small and 4-byte aligned */
BPF_ALU64_IMM(BPF_AND, BPF_REG_2, 4),
BPF_ALU64_IMM(BPF_SUB, BPF_REG_2, 8),
/* add it to fp. We now have either fp-4 or fp-8, but
* we don't know which
*/
BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_10),
selftest/bpf: Verifier tests for var-off access Add tests for the new functionality - reading and writing to the stack through a variable-offset pointer. Signed-off-by: Andrei Matei <andreimatei1@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210207011027.676572-4-andreimatei1@gmail.com
2021-02-06 20:10:26 -05:00
/* dereference it for a stack read */
BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_2, 0),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.result = ACCEPT,
.result_unpriv = REJECT,
.errstr_unpriv = "R2 variable stack access prohibited for !root",
.prog_type = BPF_PROG_TYPE_CGROUP_SKB,
},
{
"variable-offset stack read, uninitialized",
.insns = {
/* Get an unknown value */
BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, 0),
/* Make it small and 4-byte aligned */
BPF_ALU64_IMM(BPF_AND, BPF_REG_2, 4),
BPF_ALU64_IMM(BPF_SUB, BPF_REG_2, 8),
/* add it to fp. We now have either fp-4 or fp-8, but
* we don't know which
*/
BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_10),
/* dereference it for a stack read */
selftests: bpf: break up test_verifier Break up the first 10 kLoC of test verifier test cases out into smaller files. Looks like git line counting gets a little flismy above 16 bit integers, so we need two commits to break up test_verifier. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Acked-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-01-25 15:24:43 -08:00
BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_2, 0),
selftest/bpf: Verifier tests for var-off access Add tests for the new functionality - reading and writing to the stack through a variable-offset pointer. Signed-off-by: Andrei Matei <andreimatei1@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210207011027.676572-4-andreimatei1@gmail.com
2021-02-06 20:10:26 -05:00
BPF_MOV64_IMM(BPF_REG_0, 0),
selftests: bpf: break up test_verifier Break up the first 10 kLoC of test verifier test cases out into smaller files. Looks like git line counting gets a little flismy above 16 bit integers, so we need two commits to break up test_verifier. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Acked-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-01-25 15:24:43 -08:00
BPF_EXIT_INSN(),
},
.result = REJECT,
selftest/bpf: Verifier tests for var-off access Add tests for the new functionality - reading and writing to the stack through a variable-offset pointer. Signed-off-by: Andrei Matei <andreimatei1@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210207011027.676572-4-andreimatei1@gmail.com
2021-02-06 20:10:26 -05:00
.errstr = "invalid variable-offset read from stack R2",
selftests: bpf: break up test_verifier Break up the first 10 kLoC of test verifier test cases out into smaller files. Looks like git line counting gets a little flismy above 16 bit integers, so we need two commits to break up test_verifier. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Acked-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-01-25 15:24:43 -08:00
.prog_type = BPF_PROG_TYPE_LWT_IN,
},
selftest/bpf: Verifier tests for var-off access Add tests for the new functionality - reading and writing to the stack through a variable-offset pointer. Signed-off-by: Andrei Matei <andreimatei1@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210207011027.676572-4-andreimatei1@gmail.com
2021-02-06 20:10:26 -05:00
{
"variable-offset stack write, priv vs unpriv",
.insns = {
/* Get an unknown value */
BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, 0),
/* Make it small and 8-byte aligned */
BPF_ALU64_IMM(BPF_AND, BPF_REG_2, 8),
BPF_ALU64_IMM(BPF_SUB, BPF_REG_2, 16),
/* Add it to fp. We now have either fp-8 or fp-16, but
* we don't know which
*/
BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_10),
/* Dereference it for a stack write */
BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0),
/* Now read from the address we just wrote. This shows
* that, after a variable-offset write, a priviledged
* program can read the slots that were in the range of
* that write (even if the verifier doesn't actually know
* if the slot being read was really written to or not.
*/
BPF_LDX_MEM(BPF_DW, BPF_REG_3, BPF_REG_2, 0),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
/* Variable stack access is rejected for unprivileged.
*/
.errstr_unpriv = "R2 variable stack access prohibited for !root",
.result_unpriv = REJECT,
.result = ACCEPT,
},
{
"variable-offset stack write clobbers spilled regs",
.insns = {
/* Dummy instruction; needed because we need to patch the next one
* and we can't patch the first instruction.
*/
BPF_MOV64_IMM(BPF_REG_6, 0),
/* Make R0 a map ptr */
BPF_LD_MAP_FD(BPF_REG_0, 0),
/* Get an unknown value */
BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, 0),
/* Make it small and 8-byte aligned */
BPF_ALU64_IMM(BPF_AND, BPF_REG_2, 8),
BPF_ALU64_IMM(BPF_SUB, BPF_REG_2, 16),
/* Add it to fp. We now have either fp-8 or fp-16, but
* we don't know which.
*/
BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_10),
/* Spill R0(map ptr) into stack */
BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -8),
/* Dereference the unknown value for a stack write */
BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0),
/* Fill the register back into R2 */
BPF_LDX_MEM(BPF_DW, BPF_REG_2, BPF_REG_10, -8),
/* Try to dereference R2 for a memory load */
BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_2, 8),
BPF_EXIT_INSN(),
},
.fixup_map_hash_8b = { 1 },
/* The unpriviledged case is not too interesting; variable
* stack access is rejected.
*/
.errstr_unpriv = "R2 variable stack access prohibited for !root",
.result_unpriv = REJECT,
/* In the priviledged case, dereferencing a spilled-and-then-filled
* register is rejected because the previous variable offset stack
* write might have overwritten the spilled pointer (i.e. we lose track
* of the spilled register when we analyze the write).
*/
.errstr = "R2 invalid mem access 'inv'",
.result = REJECT,
},
selftests: bpf: break up test_verifier Break up the first 10 kLoC of test verifier test cases out into smaller files. Looks like git line counting gets a little flismy above 16 bit integers, so we need two commits to break up test_verifier. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Acked-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-01-25 15:24:43 -08:00
{
selftests/bpf: Test unbounded var_off stack access Test the case when reg->smax_value is too small/big and can overflow, and separately min and max values outside of stack bounds. Example of output: # ./test_verifier #856/p indirect variable-offset stack access, unbounded OK #857/p indirect variable-offset stack access, max out of bound OK #858/p indirect variable-offset stack access, min out of bound OK Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-04-03 23:22:42 -07:00
"indirect variable-offset stack access, unbounded",
.insns = {
BPF_MOV64_IMM(BPF_REG_2, 6),
BPF_MOV64_IMM(BPF_REG_3, 28),
/* Fill the top 16 bytes of the stack. */
BPF_ST_MEM(BPF_DW, BPF_REG_10, -16, 0),
BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
/* Get an unknown value. */
BPF_LDX_MEM(BPF_DW, BPF_REG_4, BPF_REG_1, offsetof(struct bpf_sock_ops,
bytes_received)),
/* Check the lower bound but don't check the upper one. */
BPF_JMP_IMM(BPF_JSLT, BPF_REG_4, 0, 4),
/* Point the lower bound to initialized stack. Offset is now in range
* from fp-16 to fp+0x7fffffffffffffef, i.e. max value is unbounded.
*/
BPF_ALU64_IMM(BPF_SUB, BPF_REG_4, 16),
BPF_ALU64_REG(BPF_ADD, BPF_REG_4, BPF_REG_10),
BPF_MOV64_IMM(BPF_REG_5, 8),
/* Dereference it indirectly. */
BPF_EMIT_CALL(BPF_FUNC_getsockopt),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
selftest/bpf: Adjust expected verifier errors The verifier errors around stack accesses have changed slightly in the previous commit (generally for the better). Signed-off-by: Andrei Matei <andreimatei1@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210207011027.676572-3-andreimatei1@gmail.com
2021-02-06 20:10:25 -05:00
.errstr = "invalid unbounded variable-offset indirect access to stack R4",
selftests/bpf: Test unbounded var_off stack access Test the case when reg->smax_value is too small/big and can overflow, and separately min and max values outside of stack bounds. Example of output: # ./test_verifier #856/p indirect variable-offset stack access, unbounded OK #857/p indirect variable-offset stack access, max out of bound OK #858/p indirect variable-offset stack access, min out of bound OK Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-04-03 23:22:42 -07:00
.result = REJECT,
.prog_type = BPF_PROG_TYPE_SOCK_OPS,
},
{
"indirect variable-offset stack access, max out of bound",
selftests: bpf: break up test_verifier Break up the first 10 kLoC of test verifier test cases out into smaller files. Looks like git line counting gets a little flismy above 16 bit integers, so we need two commits to break up test_verifier. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Acked-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-01-25 15:24:43 -08:00
.insns = {
/* Fill the top 8 bytes of the stack */
BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
/* Get an unknown value */
BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, 0),
/* Make it small and 4-byte aligned */
BPF_ALU64_IMM(BPF_AND, BPF_REG_2, 4),
BPF_ALU64_IMM(BPF_SUB, BPF_REG_2, 8),
/* add it to fp. We now have either fp-4 or fp-8, but
* we don't know which
*/
BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_10),
/* dereference it indirectly */
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.fixup_map_hash_8b = { 5 },
selftest/bpf: Adjust expected verifier errors The verifier errors around stack accesses have changed slightly in the previous commit (generally for the better). Signed-off-by: Andrei Matei <andreimatei1@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210207011027.676572-3-andreimatei1@gmail.com
2021-02-06 20:10:25 -05:00
.errstr = "invalid variable-offset indirect access to stack R2",
selftests/bpf: Test unbounded var_off stack access Test the case when reg->smax_value is too small/big and can overflow, and separately min and max values outside of stack bounds. Example of output: # ./test_verifier #856/p indirect variable-offset stack access, unbounded OK #857/p indirect variable-offset stack access, max out of bound OK #858/p indirect variable-offset stack access, min out of bound OK Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-04-03 23:22:42 -07:00
.result = REJECT,
.prog_type = BPF_PROG_TYPE_LWT_IN,
},
{
"indirect variable-offset stack access, min out of bound",
.insns = {
/* Fill the top 8 bytes of the stack */
BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
/* Get an unknown value */
BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, 0),
/* Make it small and 4-byte aligned */
BPF_ALU64_IMM(BPF_AND, BPF_REG_2, 4),
BPF_ALU64_IMM(BPF_SUB, BPF_REG_2, 516),
/* add it to fp. We now have either fp-516 or fp-512, but
* we don't know which
*/
BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_10),
/* dereference it indirectly */
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.fixup_map_hash_8b = { 5 },
selftest/bpf: Adjust expected verifier errors The verifier errors around stack accesses have changed slightly in the previous commit (generally for the better). Signed-off-by: Andrei Matei <andreimatei1@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210207011027.676572-3-andreimatei1@gmail.com
2021-02-06 20:10:25 -05:00
.errstr = "invalid variable-offset indirect access to stack R2",
selftests: bpf: break up test_verifier Break up the first 10 kLoC of test verifier test cases out into smaller files. Looks like git line counting gets a little flismy above 16 bit integers, so we need two commits to break up test_verifier. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Acked-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-01-25 15:24:43 -08:00
.result = REJECT,
.prog_type = BPF_PROG_TYPE_LWT_IN,
},
selftests/bpf: Test variable offset stack access Test different scenarios of indirect variable-offset stack access: out of bound access (>0), min_off below initialized part of the stack, max_off+size above initialized part of the stack, initialized stack. Example of output: ... #856/p indirect variable-offset stack access, out of bound OK #857/p indirect variable-offset stack access, max_off+size > max_initialized OK #858/p indirect variable-offset stack access, min_off < min_initialized OK #859/p indirect variable-offset stack access, ok OK ... Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-03-28 18:01:58 -07:00
{
"indirect variable-offset stack access, max_off+size > max_initialized",
.insns = {
/* Fill only the second from top 8 bytes of the stack. */
BPF_ST_MEM(BPF_DW, BPF_REG_10, -16, 0),
/* Get an unknown value. */
BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, 0),
/* Make it small and 4-byte aligned. */
BPF_ALU64_IMM(BPF_AND, BPF_REG_2, 4),
BPF_ALU64_IMM(BPF_SUB, BPF_REG_2, 16),
/* Add it to fp. We now have either fp-12 or fp-16, but we don't know
* which. fp-12 size 8 is partially uninitialized stack.
*/
BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_10),
/* Dereference it indirectly. */
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.fixup_map_hash_8b = { 5 },
selftest/bpf: Adjust expected verifier errors The verifier errors around stack accesses have changed slightly in the previous commit (generally for the better). Signed-off-by: Andrei Matei <andreimatei1@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210207011027.676572-3-andreimatei1@gmail.com
2021-02-06 20:10:25 -05:00
.errstr = "invalid indirect read from stack R2 var_off",
selftests/bpf: Test variable offset stack access Test different scenarios of indirect variable-offset stack access: out of bound access (>0), min_off below initialized part of the stack, max_off+size above initialized part of the stack, initialized stack. Example of output: ... #856/p indirect variable-offset stack access, out of bound OK #857/p indirect variable-offset stack access, max_off+size > max_initialized OK #858/p indirect variable-offset stack access, min_off < min_initialized OK #859/p indirect variable-offset stack access, ok OK ... Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-03-28 18:01:58 -07:00
.result = REJECT,
.prog_type = BPF_PROG_TYPE_LWT_IN,
},
{
"indirect variable-offset stack access, min_off < min_initialized",
.insns = {
/* Fill only the top 8 bytes of the stack. */
BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
/* Get an unknown value */
BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, 0),
/* Make it small and 4-byte aligned. */
BPF_ALU64_IMM(BPF_AND, BPF_REG_2, 4),
BPF_ALU64_IMM(BPF_SUB, BPF_REG_2, 16),
/* Add it to fp. We now have either fp-12 or fp-16, but we don't know
* which. fp-16 size 8 is partially uninitialized stack.
*/
BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_10),
/* Dereference it indirectly. */
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.fixup_map_hash_8b = { 5 },
selftest/bpf: Adjust expected verifier errors The verifier errors around stack accesses have changed slightly in the previous commit (generally for the better). Signed-off-by: Andrei Matei <andreimatei1@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210207011027.676572-3-andreimatei1@gmail.com
2021-02-06 20:10:25 -05:00
.errstr = "invalid indirect read from stack R2 var_off",
selftests/bpf: Test variable offset stack access Test different scenarios of indirect variable-offset stack access: out of bound access (>0), min_off below initialized part of the stack, max_off+size above initialized part of the stack, initialized stack. Example of output: ... #856/p indirect variable-offset stack access, out of bound OK #857/p indirect variable-offset stack access, max_off+size > max_initialized OK #858/p indirect variable-offset stack access, min_off < min_initialized OK #859/p indirect variable-offset stack access, ok OK ... Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-03-28 18:01:58 -07:00
.result = REJECT,
.prog_type = BPF_PROG_TYPE_LWT_IN,
},
selftests/bpf: Test indirect var_off stack access in unpriv mode Test that verifier rejects indirect stack access with variable offset in unprivileged mode and accepts same code in privileged mode. Since pointer arithmetics is prohibited in unprivileged mode verifier should reject the program even before it gets to helper call that uses variable offset, at the time when that variable offset is trying to be constructed. Example of output: # ./test_verifier ... #859/u indirect variable-offset stack access, priv vs unpriv OK #859/p indirect variable-offset stack access, priv vs unpriv OK Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-04-03 23:22:40 -07:00
{
"indirect variable-offset stack access, priv vs unpriv",
.insns = {
/* Fill the top 16 bytes of the stack. */
BPF_ST_MEM(BPF_DW, BPF_REG_10, -16, 0),
BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
/* Get an unknown value. */
BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, 0),
/* Make it small and 4-byte aligned. */
BPF_ALU64_IMM(BPF_AND, BPF_REG_2, 4),
BPF_ALU64_IMM(BPF_SUB, BPF_REG_2, 16),
/* Add it to fp. We now have either fp-12 or fp-16, we don't know
* which, but either way it points to initialized stack.
*/
BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_10),
/* Dereference it indirectly. */
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.fixup_map_hash_8b = { 6 },
selftest/bpf: Adjust expected verifier errors The verifier errors around stack accesses have changed slightly in the previous commit (generally for the better). Signed-off-by: Andrei Matei <andreimatei1@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210207011027.676572-3-andreimatei1@gmail.com
2021-02-06 20:10:25 -05:00
.errstr_unpriv = "R2 variable stack access prohibited for !root",
selftests/bpf: Test indirect var_off stack access in unpriv mode Test that verifier rejects indirect stack access with variable offset in unprivileged mode and accepts same code in privileged mode. Since pointer arithmetics is prohibited in unprivileged mode verifier should reject the program even before it gets to helper call that uses variable offset, at the time when that variable offset is trying to be constructed. Example of output: # ./test_verifier ... #859/u indirect variable-offset stack access, priv vs unpriv OK #859/p indirect variable-offset stack access, priv vs unpriv OK Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-04-03 23:22:40 -07:00
.result_unpriv = REJECT,
.result = ACCEPT,
.prog_type = BPF_PROG_TYPE_CGROUP_SKB,
},
selftests/bpf: Test indirect var_off stack access in raw mode Test that verifier rejects indirect access to uninitialized stack with variable offset. Example of output: # ./test_verifier ... #859/p indirect variable-offset stack access, uninitialized OK Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-04-03 23:22:38 -07:00
{
"indirect variable-offset stack access, uninitialized",
.insns = {
BPF_MOV64_IMM(BPF_REG_2, 6),
BPF_MOV64_IMM(BPF_REG_3, 28),
/* Fill the top 16 bytes of the stack. */
BPF_ST_MEM(BPF_W, BPF_REG_10, -16, 0),
BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
/* Get an unknown value. */
BPF_LDX_MEM(BPF_W, BPF_REG_4, BPF_REG_1, 0),
/* Make it small and 4-byte aligned. */
BPF_ALU64_IMM(BPF_AND, BPF_REG_4, 4),
BPF_ALU64_IMM(BPF_SUB, BPF_REG_4, 16),
/* Add it to fp. We now have either fp-12 or fp-16, we don't know
* which, but either way it points to initialized stack.
*/
BPF_ALU64_REG(BPF_ADD, BPF_REG_4, BPF_REG_10),
BPF_MOV64_IMM(BPF_REG_5, 8),
/* Dereference it indirectly. */
BPF_EMIT_CALL(BPF_FUNC_getsockopt),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
selftest/bpf: Adjust expected verifier errors The verifier errors around stack accesses have changed slightly in the previous commit (generally for the better). Signed-off-by: Andrei Matei <andreimatei1@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210207011027.676572-3-andreimatei1@gmail.com
2021-02-06 20:10:25 -05:00
.errstr = "invalid indirect read from stack R4 var_off",
selftests/bpf: Test indirect var_off stack access in raw mode Test that verifier rejects indirect access to uninitialized stack with variable offset. Example of output: # ./test_verifier ... #859/p indirect variable-offset stack access, uninitialized OK Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-04-03 23:22:38 -07:00
.result = REJECT,
.prog_type = BPF_PROG_TYPE_SOCK_OPS,
},
selftests/bpf: Test variable offset stack access Test different scenarios of indirect variable-offset stack access: out of bound access (>0), min_off below initialized part of the stack, max_off+size above initialized part of the stack, initialized stack. Example of output: ... #856/p indirect variable-offset stack access, out of bound OK #857/p indirect variable-offset stack access, max_off+size > max_initialized OK #858/p indirect variable-offset stack access, min_off < min_initialized OK #859/p indirect variable-offset stack access, ok OK ... Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-03-28 18:01:58 -07:00
{
"indirect variable-offset stack access, ok",
.insns = {
/* Fill the top 16 bytes of the stack. */
BPF_ST_MEM(BPF_DW, BPF_REG_10, -16, 0),
BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
/* Get an unknown value. */
BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, 0),
/* Make it small and 4-byte aligned. */
BPF_ALU64_IMM(BPF_AND, BPF_REG_2, 4),
BPF_ALU64_IMM(BPF_SUB, BPF_REG_2, 16),
/* Add it to fp. We now have either fp-12 or fp-16, we don't know
* which, but either way it points to initialized stack.
*/
BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_10),
/* Dereference it indirectly. */
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.fixup_map_hash_8b = { 6 },
.result = ACCEPT,
.prog_type = BPF_PROG_TYPE_LWT_IN,
},
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