diff options
| -rw-r--r-- | kernel/bpf/verifier.c | 6 | ||||
| -rw-r--r-- | samples/bpf/test_verifier.c | 59 |
2 files changed, 64 insertions, 1 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 039d866fd36a..cd307df98cb3 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -648,6 +648,9 @@ static int check_mem_access(struct verifier_env *env, u32 regno, int off, struct verifier_state *state = &env->cur_state; int size, err = 0; + if (state->regs[regno].type == PTR_TO_STACK) + off += state->regs[regno].imm; + size = bpf_size_to_bytes(bpf_size); if (size < 0) return size; @@ -667,7 +670,8 @@ static int check_mem_access(struct verifier_env *env, u32 regno, int off, if (!err && t == BPF_READ && value_regno >= 0) mark_reg_unknown_value(state->regs, value_regno); - } else if (state->regs[regno].type == FRAME_PTR) { + } else if (state->regs[regno].type == FRAME_PTR || + state->regs[regno].type == PTR_TO_STACK) { if (off >= 0 || off < -MAX_BPF_STACK) { verbose("invalid stack off=%d size=%d\n", off, size); return -EACCES; diff --git a/samples/bpf/test_verifier.c b/samples/bpf/test_verifier.c index 693605997abc..ee0f110c9c54 100644 --- a/samples/bpf/test_verifier.c +++ b/samples/bpf/test_verifier.c @@ -822,6 +822,65 @@ static struct bpf_test tests[] = { .result = ACCEPT, .prog_type = BPF_PROG_TYPE_SCHED_CLS, }, + { + "PTR_TO_STACK store/load", + .insns = { + BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -10), + BPF_ST_MEM(BPF_DW, BPF_REG_1, 2, 0xfaceb00c), + BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, 2), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + }, + { + "PTR_TO_STACK store/load - bad alignment on off", + .insns = { + BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -8), + BPF_ST_MEM(BPF_DW, BPF_REG_1, 2, 0xfaceb00c), + BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, 2), + BPF_EXIT_INSN(), + }, + .result = REJECT, + .errstr = "misaligned access off -6 size 8", + }, + { + "PTR_TO_STACK store/load - bad alignment on reg", + .insns = { + BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -10), + BPF_ST_MEM(BPF_DW, BPF_REG_1, 8, 0xfaceb00c), + BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, 8), + BPF_EXIT_INSN(), + }, + .result = REJECT, + .errstr = "misaligned access off -2 size 8", + }, + { + "PTR_TO_STACK store/load - out of bounds low", + .insns = { + BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -80000), + BPF_ST_MEM(BPF_DW, BPF_REG_1, 8, 0xfaceb00c), + BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, 8), + BPF_EXIT_INSN(), + }, + .result = REJECT, + .errstr = "invalid stack off=-79992 size=8", + }, + { + "PTR_TO_STACK store/load - out of bounds high", + .insns = { + BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -8), + BPF_ST_MEM(BPF_DW, BPF_REG_1, 8, 0xfaceb00c), + BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, 8), + BPF_EXIT_INSN(), + }, + .result = REJECT, + .errstr = "invalid stack off=0 size=8", + }, }; static int probe_filter_length(struct bpf_insn *fp) |