Commit 7c036ed9 authored by Roberto Sassu's avatar Roberto Sassu Committed by Alexei Starovoitov
Browse files

selftests/bpf: Add verifier tests for bpf_lookup_*_key() and bpf_key_put() 



Add verifier tests for bpf_lookup_*_key() and bpf_key_put(), to ensure that
acquired key references stored in the bpf_key structure are released, that
a non-NULL bpf_key pointer is passed to bpf_key_put(), and that key
references are not leaked.

Also, slightly modify test_verifier.c, to find the BTF ID of the attach
point for the LSM program type (currently, it is done only for TRACING).

Signed-off-by: default avatarRoberto Sassu <roberto.sassu@huawei.com>
Acked-by: default avatarKumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20220920075951.929132-11-roberto.sassu@huaweicloud.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 94fd7420

tools/testing/selftests/bpf/config

+1 −0
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ CONFIG_IPV6_GRE=y 
CONFIG_IPV6_SEG6_BPF=y

CONFIG_IPV6_SIT=y

CONFIG_IPV6_TUNNEL=y

CONFIG_KEYS=y

CONFIG_LIRC=y

CONFIG_LWTUNNEL=y

CONFIG_MPLS=y

tools/testing/selftests/bpf/test_verifier.c

+2 −1
Original line number Diff line number Diff line
@@ -1498,7 +1498,8 @@ static void do_test_single(struct bpf_test *test, bool unpriv, 
		opts.log_level = DEFAULT_LIBBPF_LOG_LEVEL;

	opts.prog_flags = pflags;



	if (prog_type == BPF_PROG_TYPE_TRACING && test->kfunc) {

	if ((prog_type == BPF_PROG_TYPE_TRACING ||

	     prog_type == BPF_PROG_TYPE_LSM) && test->kfunc) {

		int attach_btf_id;



		attach_btf_id = libbpf_find_vmlinux_btf_id(test->kfunc,

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

+139 −0
Original line number Diff line number Diff line
@@ -84,6 +84,145 @@ 
	.errstr = "Unreleased reference",

	.result = REJECT,

},

{

	"reference tracking: acquire/release user key reference",

	.insns = {

	BPF_MOV64_IMM(BPF_REG_1, -3),

	BPF_MOV64_IMM(BPF_REG_2, 0),

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

	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2),

	BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),

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

	BPF_MOV64_IMM(BPF_REG_0, 0),

	BPF_EXIT_INSN(),

	},

	.prog_type = BPF_PROG_TYPE_LSM,

	.kfunc = "bpf",

	.expected_attach_type = BPF_LSM_MAC,

	.flags = BPF_F_SLEEPABLE,

	.fixup_kfunc_btf_id = {

		{ "bpf_lookup_user_key", 2 },

		{ "bpf_key_put", 5 },

	},

	.result = ACCEPT,

},

{

	"reference tracking: acquire/release system key reference",

	.insns = {

	BPF_MOV64_IMM(BPF_REG_1, 1),

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

	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2),

	BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),

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

	BPF_MOV64_IMM(BPF_REG_0, 0),

	BPF_EXIT_INSN(),

	},

	.prog_type = BPF_PROG_TYPE_LSM,

	.kfunc = "bpf",

	.expected_attach_type = BPF_LSM_MAC,

	.flags = BPF_F_SLEEPABLE,

	.fixup_kfunc_btf_id = {

		{ "bpf_lookup_system_key", 1 },

		{ "bpf_key_put", 4 },

	},

	.result = ACCEPT,

},

{

	"reference tracking: release user key reference without check",

	.insns = {

	BPF_MOV64_IMM(BPF_REG_1, -3),

	BPF_MOV64_IMM(BPF_REG_2, 0),

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

	BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),

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

	BPF_MOV64_IMM(BPF_REG_0, 0),

	BPF_EXIT_INSN(),

	},

	.prog_type = BPF_PROG_TYPE_LSM,

	.kfunc = "bpf",

	.expected_attach_type = BPF_LSM_MAC,

	.flags = BPF_F_SLEEPABLE,

	.errstr = "arg#0 pointer type STRUCT bpf_key must point to scalar, or struct with scalar",

	.fixup_kfunc_btf_id = {

		{ "bpf_lookup_user_key", 2 },

		{ "bpf_key_put", 4 },

	},

	.result = REJECT,

},

{

	"reference tracking: release system key reference without check",

	.insns = {

	BPF_MOV64_IMM(BPF_REG_1, 1),

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

	BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),

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

	BPF_MOV64_IMM(BPF_REG_0, 0),

	BPF_EXIT_INSN(),

	},

	.prog_type = BPF_PROG_TYPE_LSM,

	.kfunc = "bpf",

	.expected_attach_type = BPF_LSM_MAC,

	.flags = BPF_F_SLEEPABLE,

	.errstr = "arg#0 pointer type STRUCT bpf_key must point to scalar, or struct with scalar",

	.fixup_kfunc_btf_id = {

		{ "bpf_lookup_system_key", 1 },

		{ "bpf_key_put", 3 },

	},

	.result = REJECT,

},

{

	"reference tracking: release with NULL key pointer",

	.insns = {

	BPF_MOV64_IMM(BPF_REG_1, 0),

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

	BPF_MOV64_IMM(BPF_REG_0, 0),

	BPF_EXIT_INSN(),

	},

	.prog_type = BPF_PROG_TYPE_LSM,

	.kfunc = "bpf",

	.expected_attach_type = BPF_LSM_MAC,

	.flags = BPF_F_SLEEPABLE,

	.errstr = "arg#0 pointer type STRUCT bpf_key must point to scalar, or struct with scalar",

	.fixup_kfunc_btf_id = {

		{ "bpf_key_put", 1 },

	},

	.result = REJECT,

},

{

	"reference tracking: leak potential reference to user key",

	.insns = {

	BPF_MOV64_IMM(BPF_REG_1, -3),

	BPF_MOV64_IMM(BPF_REG_2, 0),

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

	BPF_EXIT_INSN(),

	},

	.prog_type = BPF_PROG_TYPE_LSM,

	.kfunc = "bpf",

	.expected_attach_type = BPF_LSM_MAC,

	.flags = BPF_F_SLEEPABLE,

	.errstr = "Unreleased reference",

	.fixup_kfunc_btf_id = {

		{ "bpf_lookup_user_key", 2 },

	},

	.result = REJECT,

},

{

	"reference tracking: leak potential reference to system key",

	.insns = {

	BPF_MOV64_IMM(BPF_REG_1, 1),

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

	BPF_EXIT_INSN(),

	},

	.prog_type = BPF_PROG_TYPE_LSM,

	.kfunc = "bpf",

	.expected_attach_type = BPF_LSM_MAC,

	.flags = BPF_F_SLEEPABLE,

	.errstr = "Unreleased reference",

	.fixup_kfunc_btf_id = {

		{ "bpf_lookup_system_key", 1 },

	},

	.result = REJECT,

},

{

	"reference tracking: release reference without check",

	.insns = {