diff options
Diffstat (limited to '')
| -rw-r--r-- | tools/testing/selftests/bpf/progs/verifier_global_ptr_args.c | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/verifier_global_ptr_args.c b/tools/testing/selftests/bpf/progs/verifier_global_ptr_args.c new file mode 100644 index 000000000000..4ab0ef18d7eb --- /dev/null +++ b/tools/testing/selftests/bpf/progs/verifier_global_ptr_args.c @@ -0,0 +1,182 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */ + +#include <vmlinux.h> +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.h> +#include <bpf/bpf_core_read.h> +#include "bpf_misc.h" +#include "xdp_metadata.h" +#include "bpf_kfuncs.h" + +extern struct task_struct *bpf_task_acquire(struct task_struct *p) __ksym __weak; +extern void bpf_task_release(struct task_struct *p) __ksym __weak; + +__weak int subprog_trusted_task_nullable(struct task_struct *task __arg_trusted __arg_nullable) +{ + if (!task) + return 0; + return task->pid + task->tgid; +} + +__weak int subprog_trusted_task_nullable_extra_layer(struct task_struct *task __arg_trusted __arg_nullable) +{ + return subprog_trusted_task_nullable(task) + subprog_trusted_task_nullable(NULL); +} + +SEC("?tp_btf/task_newtask") +__success __log_level(2) +__msg("Validating subprog_trusted_task_nullable() func#1...") +__msg(": R1=trusted_ptr_or_null_task_struct(") +int trusted_task_arg_nullable(void *ctx) +{ + struct task_struct *t1 = bpf_get_current_task_btf(); + struct task_struct *t2 = bpf_task_acquire(t1); + int res = 0; + + /* known NULL */ + res += subprog_trusted_task_nullable(NULL); + + /* known non-NULL */ + res += subprog_trusted_task_nullable(t1); + res += subprog_trusted_task_nullable_extra_layer(t1); + + /* unknown if NULL or not */ + res += subprog_trusted_task_nullable(t2); + res += subprog_trusted_task_nullable_extra_layer(t2); + + if (t2) { + /* known non-NULL after explicit NULL check, just in case */ + res += subprog_trusted_task_nullable(t2); + res += subprog_trusted_task_nullable_extra_layer(t2); + + bpf_task_release(t2); + } + + return res; +} + +__weak int subprog_trusted_task_nonnull(struct task_struct *task __arg_trusted) +{ + return task->pid + task->tgid; +} + +SEC("?kprobe") +__failure __log_level(2) +__msg("R1 type=scalar expected=ptr_, trusted_ptr_, rcu_ptr_") +__msg("Caller passes invalid args into func#1 ('subprog_trusted_task_nonnull')") +int trusted_task_arg_nonnull_fail1(void *ctx) +{ + return subprog_trusted_task_nonnull(NULL); +} + +SEC("?tp_btf/task_newtask") +__failure __log_level(2) +__msg("R1 type=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) +{ + struct task_struct *t = bpf_get_current_task_btf(); + struct task_struct *nullable; + int res; + + nullable = bpf_task_acquire(t); + + /* should fail, PTR_TO_BTF_ID_OR_NULL */ + res = subprog_trusted_task_nonnull(nullable); + + if (nullable) + bpf_task_release(nullable); + + return res; +} + +SEC("?kprobe") +__success __log_level(2) +__msg("Validating subprog_trusted_task_nonnull() func#1...") +__msg(": R1=trusted_ptr_task_struct(") +int trusted_task_arg_nonnull(void *ctx) +{ + struct task_struct *t = bpf_get_current_task_btf(); + + return subprog_trusted_task_nonnull(t); +} + +struct task_struct___local {} __attribute__((preserve_access_index)); + +__weak int subprog_nullable_task_flavor( + struct task_struct___local *task __arg_trusted __arg_nullable) +{ + char buf[16]; + + if (!task) + return 0; + + return bpf_copy_from_user_task(&buf, sizeof(buf), NULL, (void *)task, 0); +} + +SEC("?uprobe.s") +__success __log_level(2) +__msg("Validating subprog_nullable_task_flavor() func#1...") +__msg(": R1=trusted_ptr_or_null_task_struct(") +int flavor_ptr_nullable(void *ctx) +{ + struct task_struct___local *t = (void *)bpf_get_current_task_btf(); + + return subprog_nullable_task_flavor(t); +} + +__weak int subprog_nonnull_task_flavor(struct task_struct___local *task __arg_trusted) +{ + char buf[16]; + + return bpf_copy_from_user_task(&buf, sizeof(buf), NULL, (void *)task, 0); +} + +SEC("?uprobe.s") +__success __log_level(2) +__msg("Validating subprog_nonnull_task_flavor() func#1...") +__msg(": R1=trusted_ptr_task_struct(") +int flavor_ptr_nonnull(void *ctx) +{ + struct task_struct *t = bpf_get_current_task_btf(); + + return subprog_nonnull_task_flavor((void *)t); +} + +__weak int subprog_trusted_destroy(struct task_struct *task __arg_trusted) +{ + bpf_task_release(task); /* should be rejected */ + + return 0; +} + +SEC("?tp_btf/task_newtask") +__failure __log_level(2) +__msg("release kernel function bpf_task_release expects refcounted PTR_TO_BTF_ID") +int BPF_PROG(trusted_destroy_fail, struct task_struct *task, u64 clone_flags) +{ + return subprog_trusted_destroy(task); +} + +__weak int subprog_trusted_acq_rel(struct task_struct *task __arg_trusted) +{ + struct task_struct *owned; + + owned = bpf_task_acquire(task); + if (!owned) + return 0; + + bpf_task_release(owned); /* this one is OK, we acquired it locally */ + + return 0; +} + +SEC("?tp_btf/task_newtask") +__success __log_level(2) +int BPF_PROG(trusted_acq_rel, struct task_struct *task, u64 clone_flags) +{ + return subprog_trusted_acq_rel(task); +} + +char _license[] SEC("license") = "GPL"; |