diff options
| -rw-r--r-- | kernel/bpf/verifier.c | 31 |
1 files changed, 28 insertions, 3 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 93716da57d48..9426367fc911 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -4438,6 +4438,11 @@ static int backtrack_insn(struct bpf_verifier_env *env, int idx, int subseq_idx, bt_reg_mask(bt)); return -EFAULT; } + if (insn->src_reg == BPF_REG_0 && insn->imm == BPF_FUNC_tail_call + && subseq_idx - idx != 1) { + if (bt_subprog_enter(bt)) + return -EFAULT; + } } else if (opcode == BPF_EXIT) { bool r0_precise; @@ -11064,6 +11069,10 @@ static int prepare_func_exit(struct bpf_verifier_env *env, int *insn_idx) bool in_callback_fn; int err; + err = bpf_update_live_stack(env); + if (err) + return err; + callee = state->frame[state->curframe]; r0 = &callee->regs[BPF_REG_0]; if (r0->type == PTR_TO_STACK) { @@ -11970,6 +11979,25 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn env->prog->call_get_func_ip = true; } + if (func_id == BPF_FUNC_tail_call) { + if (env->cur_state->curframe) { + struct bpf_verifier_state *branch; + + mark_reg_scratched(env, BPF_REG_0); + branch = push_stack(env, env->insn_idx + 1, env->insn_idx, false); + if (IS_ERR(branch)) + return PTR_ERR(branch); + clear_all_pkt_pointers(env); + mark_reg_unknown(env, regs, BPF_REG_0); + err = prepare_func_exit(env, &env->insn_idx); + if (err) + return err; + env->insn_idx--; + } else { + changes_data = false; + } + } + if (changes_data) clear_all_pkt_pointers(env); return 0; @@ -20146,9 +20174,6 @@ static int process_bpf_exit_full(struct bpf_verifier_env *env, return PROCESS_BPF_EXIT; if (env->cur_state->curframe) { - err = bpf_update_live_stack(env); - if (err) - return err; /* exit from nested function */ err = prepare_func_exit(env, &env->insn_idx); if (err) |