diff options
| -rw-r--r-- | kernel/bpf/verifier.c | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 3af8bd838b82..9c6ad157a61e 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -6045,7 +6045,13 @@ static int check_ptr_to_btf_access(struct bpf_verifier_env *env, return -EACCES; } - if (type_is_alloc(reg->type) && !type_is_non_owning_ref(reg->type) && + /* + * A fault-prone allocated object may still be read through a + * BPF_PROBE_MEM load after its lifetime protection ends. Writes + * through such pointers were rejected above. + */ + if (type_is_alloc(reg->type) && !bpf_may_fault_on_deref(reg->type) && + !type_is_non_owning_ref(reg->type) && !(reg->type & MEM_RCU) && !reg_is_referenced(env, reg)) { verifier_bug(env, "allocated object must have a referenced id"); return -EFAULT; @@ -7423,10 +7429,14 @@ static int process_spin_lock(struct bpf_verifier_env *env, struct bpf_reg_state lock); return -EINVAL; } + /* + * Invalidate non-owning refs before RCU demotion clears their + * NON_OWN_REF flag. + */ + invalidate_non_owning_refs(env); + if (!in_rcu_cs(env)) invalidate_rcu_protected_refs(env); - - invalidate_non_owning_refs(env); } return 0; } @@ -9526,7 +9536,7 @@ static void invalidate_rcu_protected_refs(struct bpf_verifier_env *env) bpf_for_each_reg_in_vstate_mask(env->cur_state, state, reg, stack, clear_mask, ({ if (reg->type & MEM_RCU) { bpf_diag_mod_begin(env, reg, NULL, BPF_DIAG_MOD_WRITE); - reg->type &= ~(MEM_RCU | PTR_MAYBE_NULL); + reg->type &= ~(MEM_RCU | PTR_MAYBE_NULL | NON_OWN_REF); reg->type |= PTR_UNTRUSTED; bpf_diag_mod_end(env); } |