Commit 806f81cd authored by Eduard Zingerman's avatar Eduard Zingerman Committed by Alexei Starovoitov
Browse files

selftests/bpf: test if pointer type is tracked for BPF_ST_MEM 



Check that verifier tracks pointer types for BPF_ST_MEM instructions
and reports error if pointer types do not match for different
execution branches.

Signed-off-by: default avatarEduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230304011247.566040-3-eddyz87@gmail.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 0d80a619

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

+23 −0
Original line number Diff line number Diff line
@@ -239,6 +239,29 @@ 
	.errstr = "same insn cannot be used with different pointers",

	.prog_type = BPF_PROG_TYPE_SCHED_CLS,

},

{

	/* Same as above, but use BPF_ST_MEM to save 42

	 * instead of BPF_STX_MEM.

	 */

	"unpriv: spill/fill of different pointers st",

	.insns = {

	BPF_ALU64_REG(BPF_MOV, BPF_REG_6, BPF_REG_10),

	BPF_ALU64_IMM(BPF_ADD, BPF_REG_6, -8),

	BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 3),

	BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),

	BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -16),

	BPF_STX_MEM(BPF_DW, BPF_REG_6, BPF_REG_2, 0),

	BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 1),

	BPF_STX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1, 0),

	BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_6, 0),

	BPF_ST_MEM(BPF_W, BPF_REG_1, offsetof(struct __sk_buff, mark), 42),

	BPF_MOV64_IMM(BPF_REG_0, 0),

	BPF_EXIT_INSN(),

	},

	.result = REJECT,

	.errstr = "same insn cannot be used with different pointers",

	.prog_type = BPF_PROG_TYPE_SCHED_CLS,

},

{

	"unpriv: spill/fill of different pointers stx - ctx and sock",

	.insns = {