Commit ca796fe6 authored by Daniel Borkmann's avatar Daniel Borkmann Committed by Alexei Starovoitov
Browse files

bpf, selftests: Add verifier test for mem_or_null register with offset. 



Add a new test case with mem_or_null typed register with off > 0 to ensure
it gets rejected by the verifier:

  # ./test_verifier 1011
  #1009/u check with invalid reg offset 0 OK
  #1009/p check with invalid reg offset 0 OK
  Summary: 2 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent e60b0d12

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

+28 −0
Original line number Diff line number Diff line
@@ -58,6 +58,34 @@ 
	.result = ACCEPT,

	.result_unpriv = ACCEPT,

},

{

	"check with invalid reg offset 0",

	.insns = {

	/* reserve 8 byte ringbuf memory */

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

	BPF_LD_MAP_FD(BPF_REG_1, 0),

	BPF_MOV64_IMM(BPF_REG_2, 8),

	BPF_MOV64_IMM(BPF_REG_3, 0),

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

	/* store a pointer to the reserved memory in R6 */

	BPF_MOV64_REG(BPF_REG_6, BPF_REG_0),

	/* add invalid offset to memory or NULL */

	BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 1),

	/* check whether the reservation was successful */

	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 4),

	/* should not be able to access *(R7) = 0 */

	BPF_ST_MEM(BPF_W, BPF_REG_6, 0, 0),

	/* submit the reserved ringbuf memory */

	BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),

	BPF_MOV64_IMM(BPF_REG_2, 0),

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

	BPF_MOV64_IMM(BPF_REG_0, 0),

	BPF_EXIT_INSN(),

	},

	.fixup_map_ringbuf = { 1 },

	.result = REJECT,

	.errstr = "R0 pointer arithmetic on mem_or_null prohibited",

},

{

	"check corrupted spill/fill",

	.insns = {