Commit 583c7ce5 authored by Eduard Zingerman's avatar Eduard Zingerman Committed by Alexei Starovoitov
Browse files

selftests/bpf: verifier/leak_ptr.c converted to inline assembly 



Test verifier/leak_ptr.c automatically converted to use inline assembly.

Signed-off-by: default avatarEduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230325025524.144043-27-eddyz87@gmail.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent e2978755

tools/testing/selftests/bpf/prog_tests/verifier.c

+2 −0
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ 
#include "verifier_helper_value_access.skel.h"

#include "verifier_int_ptr.skel.h"

#include "verifier_ld_ind.skel.h"

#include "verifier_leak_ptr.skel.h"



__maybe_unused

static void run_tests_aux(const char *skel_name, skel_elf_bytes_fn elf_bytes_factory)
@@ -68,3 +69,4 @@ void test_verifier_helper_restricted(void) { RUN(verifier_helper_restricted); 
void test_verifier_helper_value_access(void)  { RUN(verifier_helper_value_access); }

void test_verifier_int_ptr(void)              { RUN(verifier_int_ptr); }

void test_verifier_ld_ind(void)               { RUN(verifier_ld_ind); }

void test_verifier_leak_ptr(void)             { RUN(verifier_leak_ptr); }

tools/testing/selftests/bpf/progs/verifier_leak_ptr.c

0 → 100644
+92 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/* Converted from tools/testing/selftests/bpf/verifier/leak_ptr.c */



#include <linux/bpf.h>

#include <bpf/bpf_helpers.h>

#include "bpf_misc.h"



struct {

	__uint(type, BPF_MAP_TYPE_HASH);

	__uint(max_entries, 1);

	__type(key, long long);

	__type(value, long long);

} map_hash_8b SEC(".maps");



SEC("socket")

__description("leak pointer into ctx 1")

__failure __msg("BPF_ATOMIC stores into R1 ctx is not allowed")

__failure_unpriv __msg_unpriv("R2 leaks addr into mem")

__naked void leak_pointer_into_ctx_1(void)

{

	asm volatile ("					\

	r0 = 0;						\

	*(u64*)(r1 + %[__sk_buff_cb_0]) = r0;		\

	r2 = %[map_hash_8b] ll;				\

	lock *(u64 *)(r1 + %[__sk_buff_cb_0]) += r2;	\

	exit;						\

"	:

	: __imm_addr(map_hash_8b),

	  __imm_const(__sk_buff_cb_0, offsetof(struct __sk_buff, cb[0]))

	: __clobber_all);

}



SEC("socket")

__description("leak pointer into ctx 2")

__failure __msg("BPF_ATOMIC stores into R1 ctx is not allowed")

__failure_unpriv __msg_unpriv("R10 leaks addr into mem")

__naked void leak_pointer_into_ctx_2(void)

{

	asm volatile ("					\

	r0 = 0;						\

	*(u64*)(r1 + %[__sk_buff_cb_0]) = r0;		\

	lock *(u64 *)(r1 + %[__sk_buff_cb_0]) += r10;	\

	exit;						\

"	:

	: __imm_const(__sk_buff_cb_0, offsetof(struct __sk_buff, cb[0]))

	: __clobber_all);

}



SEC("socket")

__description("leak pointer into ctx 3")

__success __failure_unpriv __msg_unpriv("R2 leaks addr into ctx")

__retval(0)

__naked void leak_pointer_into_ctx_3(void)

{

	asm volatile ("					\

	r0 = 0;						\

	r2 = %[map_hash_8b] ll;				\

	*(u64*)(r1 + %[__sk_buff_cb_0]) = r2;		\

	exit;						\

"	:

	: __imm_addr(map_hash_8b),

	  __imm_const(__sk_buff_cb_0, offsetof(struct __sk_buff, cb[0]))

	: __clobber_all);

}



SEC("socket")

__description("leak pointer into map val")

__success __failure_unpriv __msg_unpriv("R6 leaks addr into mem")

__retval(0)

__naked void leak_pointer_into_map_val(void)

{

	asm volatile ("					\

	r6 = r1;					\

	r1 = 0;						\

	*(u64*)(r10 - 8) = r1;				\

	r2 = r10;					\

	r2 += -8;					\

	r1 = %[map_hash_8b] ll;				\

	call %[bpf_map_lookup_elem];			\

	if r0 == 0 goto l0_%=;				\

	r3 = 0;						\

	*(u64*)(r0 + 0) = r3;				\

	lock *(u64 *)(r0 + 0) += r6;			\

l0_%=:	r0 = 0;						\

	exit;						\

"	:

	: __imm(bpf_map_lookup_elem),

	  __imm_addr(map_hash_8b)

	: __clobber_all);

}



char _license[] SEC("license") = "GPL";

tools/testing/selftests/bpf/verifier/leak_ptr.c

deleted100644 → 0
+0 −67
Original line number Diff line number Diff line 
{

	"leak pointer into ctx 1",

	.insns = {

	BPF_MOV64_IMM(BPF_REG_0, 0),

	BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0,

		    offsetof(struct __sk_buff, cb[0])),

	BPF_LD_MAP_FD(BPF_REG_2, 0),

	BPF_ATOMIC_OP(BPF_DW, BPF_ADD, BPF_REG_1, BPF_REG_2,

		      offsetof(struct __sk_buff, cb[0])),

	BPF_EXIT_INSN(),

	},

	.fixup_map_hash_8b = { 2 },

	.errstr_unpriv = "R2 leaks addr into mem",

	.result_unpriv = REJECT,

	.result = REJECT,

	.errstr = "BPF_ATOMIC stores into R1 ctx is not allowed",

},

{

	"leak pointer into ctx 2",

	.insns = {

	BPF_MOV64_IMM(BPF_REG_0, 0),

	BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0,

		    offsetof(struct __sk_buff, cb[0])),

	BPF_ATOMIC_OP(BPF_DW, BPF_ADD, BPF_REG_1, BPF_REG_10,

		      offsetof(struct __sk_buff, cb[0])),

	BPF_EXIT_INSN(),

	},

	.errstr_unpriv = "R10 leaks addr into mem",

	.result_unpriv = REJECT,

	.result = REJECT,

	.errstr = "BPF_ATOMIC stores into R1 ctx is not allowed",

},

{

	"leak pointer into ctx 3",

	.insns = {

	BPF_MOV64_IMM(BPF_REG_0, 0),

	BPF_LD_MAP_FD(BPF_REG_2, 0),

	BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_2,

		      offsetof(struct __sk_buff, cb[0])),

	BPF_EXIT_INSN(),

	},

	.fixup_map_hash_8b = { 1 },

	.errstr_unpriv = "R2 leaks addr into ctx",

	.result_unpriv = REJECT,

	.result = ACCEPT,

},

{

	"leak pointer into map val",

	.insns = {

	BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),

	BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),

	BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),

	BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),

	BPF_LD_MAP_FD(BPF_REG_1, 0),

	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),

	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3),

	BPF_MOV64_IMM(BPF_REG_3, 0),

	BPF_STX_MEM(BPF_DW, BPF_REG_0, BPF_REG_3, 0),

	BPF_ATOMIC_OP(BPF_DW, BPF_ADD, BPF_REG_0, BPF_REG_6, 0),

	BPF_MOV64_IMM(BPF_REG_0, 0),

	BPF_EXIT_INSN(),

	},

	.fixup_map_hash_8b = { 4 },

	.errstr_unpriv = "R6 leaks addr into mem",

	.result_unpriv = REJECT,

	.result = ACCEPT,

},