Commit 34a2cc6e authored by Jakub Sitnicki's avatar Jakub Sitnicki Committed by Daniel Borkmann
Browse files

selftests/bpf: Test that lookup on SOCKMAP/SOCKHASH is allowed 



Now that bpf_map_lookup_elem() is white-listed for SOCKMAP/SOCKHASH,
replace the tests which check that verifier prevents lookup on these map
types with ones that ensure that lookup operation is permitted, but only
with a release of acquired socket reference.

Signed-off-by: default avatarJakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarJohn Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200429181154.479310-3-jakub@cloudflare.com
parent 64d85290

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

+0 −30
Original line number Diff line number Diff line 
{

	"prevent map lookup in sockmap",

	.insns = {

	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_EXIT_INSN(),

	},

	.fixup_map_sockmap = { 3 },

	.result = REJECT,

	.errstr = "cannot pass map_type 15 into func bpf_map_lookup_elem",

	.prog_type = BPF_PROG_TYPE_SOCK_OPS,

},

{

	"prevent map lookup in sockhash",

	.insns = {

	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_EXIT_INSN(),

	},

	.fixup_map_sockhash = { 3 },

	.result = REJECT,

	.errstr = "cannot pass map_type 18 into func bpf_map_lookup_elem",

	.prog_type = BPF_PROG_TYPE_SOCK_OPS,

},

{

	"prevent map lookup in stack trace",

	.insns = {

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

+70 −0
Original line number Diff line number Diff line
@@ -516,3 +516,73 @@ 
	.prog_type = BPF_PROG_TYPE_XDP,

	.result = ACCEPT,

},

{

	"bpf_map_lookup_elem(sockmap, &key)",

	.insns = {

	BPF_ST_MEM(BPF_W, BPF_REG_10, -4, 0),

	BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),

	BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4),

	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_sockmap = { 3 },

	.prog_type = BPF_PROG_TYPE_SK_SKB,

	.result = REJECT,

	.errstr = "Unreleased reference id=2 alloc_insn=5",

},

{

	"bpf_map_lookup_elem(sockhash, &key)",

	.insns = {

	BPF_ST_MEM(BPF_W, BPF_REG_10, -4, 0),

	BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),

	BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4),

	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_sockhash = { 3 },

	.prog_type = BPF_PROG_TYPE_SK_SKB,

	.result = REJECT,

	.errstr = "Unreleased reference id=2 alloc_insn=5",

},

{

	"bpf_map_lookup_elem(sockmap, &key); sk->type [fullsock field]; bpf_sk_release(sk)",

	.insns = {

	BPF_ST_MEM(BPF_W, BPF_REG_10, -4, 0),

	BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),

	BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4),

	BPF_LD_MAP_FD(BPF_REG_1, 0),

	BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),

	BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),

	BPF_EXIT_INSN(),

	BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),

	BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_0, offsetof(struct bpf_sock, type)),

	BPF_EMIT_CALL(BPF_FUNC_sk_release),

	BPF_EXIT_INSN(),

	},

	.fixup_map_sockmap = { 3 },

	.prog_type = BPF_PROG_TYPE_SK_SKB,

	.result = ACCEPT,

},

{

	"bpf_map_lookup_elem(sockhash, &key); sk->type [fullsock field]; bpf_sk_release(sk)",

	.insns = {

	BPF_ST_MEM(BPF_W, BPF_REG_10, -4, 0),

	BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),

	BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4),

	BPF_LD_MAP_FD(BPF_REG_1, 0),

	BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),

	BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),

	BPF_EXIT_INSN(),

	BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),

	BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_0, offsetof(struct bpf_sock, type)),

	BPF_EMIT_CALL(BPF_FUNC_sk_release),

	BPF_EXIT_INSN(),

	},

	.fixup_map_sockhash = { 3 },

	.prog_type = BPF_PROG_TYPE_SK_SKB,

	.result = ACCEPT,

},

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