diff options
5 files changed, 34 insertions, 22 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 45733bae271d..faa1ecc1fe9d 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -14212,26 +14212,38 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, if (is_kfunc_rcu_protected(&meta)) regs[BPF_REG_0].type |= MEM_RCU; } else { - mark_reg_known_zero(env, regs, BPF_REG_0); - regs[BPF_REG_0].btf = desc_btf; - regs[BPF_REG_0].type = PTR_TO_BTF_ID; - regs[BPF_REG_0].btf_id = ptr_type_id; + enum bpf_reg_type type = PTR_TO_BTF_ID; if (meta.func_id == special_kfunc_list[KF_bpf_get_kmem_cache]) - regs[BPF_REG_0].type |= PTR_UNTRUSTED; - else if (is_kfunc_rcu_protected(&meta)) - regs[BPF_REG_0].type |= MEM_RCU; - - if (is_iter_next_kfunc(&meta)) { - struct bpf_reg_state *cur_iter; - - cur_iter = get_iter_from_state(env->cur_state, &meta); - - if (cur_iter->type & MEM_RCU) /* KF_RCU_PROTECTED */ - regs[BPF_REG_0].type |= MEM_RCU; - else - regs[BPF_REG_0].type |= PTR_TRUSTED; + type |= PTR_UNTRUSTED; + else if (is_kfunc_rcu_protected(&meta) || + (is_iter_next_kfunc(&meta) && + (get_iter_from_state(env->cur_state, &meta) + ->type & MEM_RCU))) { + /* + * If the iterator's constructor (the _new + * function e.g., bpf_iter_task_new) has been + * annotated with BPF kfunc flag + * KF_RCU_PROTECTED and was called within a RCU + * read-side critical section, also propagate + * the MEM_RCU flag to the pointer returned from + * the iterator's next function (e.g., + * bpf_iter_task_next). + */ + type |= MEM_RCU; + } else { + /* + * Any PTR_TO_BTF_ID that is returned from a BPF + * kfunc should by default be treated as + * implicitly trusted. + */ + type |= PTR_TRUSTED; } + + mark_reg_known_zero(env, regs, BPF_REG_0); + regs[BPF_REG_0].btf = desc_btf; + regs[BPF_REG_0].type = type; + regs[BPF_REG_0].btf_id = ptr_type_id; } if (is_kfunc_ret_null(&meta)) { diff --git a/tools/testing/selftests/bpf/progs/map_kptr_fail.c b/tools/testing/selftests/bpf/progs/map_kptr_fail.c index 4c0ff01f1a96..6443b320c732 100644 --- a/tools/testing/selftests/bpf/progs/map_kptr_fail.c +++ b/tools/testing/selftests/bpf/progs/map_kptr_fail.c @@ -272,7 +272,7 @@ int reject_untrusted_xchg(struct __sk_buff *ctx) SEC("?tc") __failure -__msg("invalid kptr access, R2 type=ptr_prog_test_ref_kfunc expected=ptr_prog_test_member") +__msg("invalid kptr access, R2 type=trusted_ptr_prog_test_ref_kfunc expected=ptr_prog_test_member") int reject_bad_type_xchg(struct __sk_buff *ctx) { struct prog_test_ref_kfunc *ref_ptr; @@ -291,7 +291,7 @@ int reject_bad_type_xchg(struct __sk_buff *ctx) } SEC("?tc") -__failure __msg("invalid kptr access, R2 type=ptr_prog_test_ref_kfunc") +__failure __msg("invalid kptr access, R2 type=trusted_ptr_prog_test_ref_kfunc") int reject_member_of_ref_xchg(struct __sk_buff *ctx) { struct prog_test_ref_kfunc *ref_ptr; diff --git a/tools/testing/selftests/bpf/progs/struct_ops_kptr_return_fail__wrong_type.c b/tools/testing/selftests/bpf/progs/struct_ops_kptr_return_fail__wrong_type.c index 6a2dd5367802..c8d217e89eea 100644 --- a/tools/testing/selftests/bpf/progs/struct_ops_kptr_return_fail__wrong_type.c +++ b/tools/testing/selftests/bpf/progs/struct_ops_kptr_return_fail__wrong_type.c @@ -12,7 +12,7 @@ void bpf_task_release(struct task_struct *p) __ksym; * reject programs returning a referenced kptr of the wrong type. */ SEC("struct_ops/test_return_ref_kptr") -__failure __msg("At program exit the register R0 is not a known value (ptr_or_null_)") +__failure __msg("At program exit the register R0 is not a known value (trusted_ptr_or_null_)") struct task_struct *BPF_PROG(kptr_return_fail__wrong_type, int dummy, struct task_struct *task, struct cgroup *cgrp) { diff --git a/tools/testing/selftests/bpf/progs/verifier_global_ptr_args.c b/tools/testing/selftests/bpf/progs/verifier_global_ptr_args.c index 1204fbc58178..e7dae0cf9c17 100644 --- a/tools/testing/selftests/bpf/progs/verifier_global_ptr_args.c +++ b/tools/testing/selftests/bpf/progs/verifier_global_ptr_args.c @@ -72,7 +72,7 @@ int trusted_task_arg_nonnull_fail1(void *ctx) SEC("?tp_btf/task_newtask") __failure __log_level(2) -__msg("R1 type=ptr_or_null_ expected=ptr_, trusted_ptr_, rcu_ptr_") +__msg("R1 type=trusted_ptr_or_null_ expected=ptr_, trusted_ptr_, rcu_ptr_") __msg("Caller passes invalid args into func#1 ('subprog_trusted_task_nonnull')") int trusted_task_arg_nonnull_fail2(void *ctx) { diff --git a/tools/testing/selftests/bpf/verifier/calls.c b/tools/testing/selftests/bpf/verifier/calls.c index c8d640802cce..9ca83dce100d 100644 --- a/tools/testing/selftests/bpf/verifier/calls.c +++ b/tools/testing/selftests/bpf/verifier/calls.c @@ -220,7 +220,7 @@ }, .result_unpriv = REJECT, .result = REJECT, - .errstr = "variable ptr_ access var_off=(0x0; 0x7) disallowed", + .errstr = "variable trusted_ptr_ access var_off=(0x0; 0x7) disallowed", }, { "calls: invalid kfunc call: referenced arg needs refcounted PTR_TO_BTF_ID", |