diff options
Diffstat (limited to 'tools/testing/selftests/bpf/progs/cgrp_kfunc_failure.c')
| -rw-r--r-- | tools/testing/selftests/bpf/progs/cgrp_kfunc_failure.c | 247 |
1 files changed, 247 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/cgrp_kfunc_failure.c b/tools/testing/selftests/bpf/progs/cgrp_kfunc_failure.c new file mode 100644 index 000000000000..9fe9c4a4e8f6 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/cgrp_kfunc_failure.c @@ -0,0 +1,247 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */ + +#include <vmlinux.h> +#include <bpf/bpf_tracing.h> +#include <bpf/bpf_helpers.h> + +#include "bpf_misc.h" +#include "cgrp_kfunc_common.h" + +char _license[] SEC("license") = "GPL"; + +/* Prototype for all of the program trace events below: + * + * TRACE_EVENT(cgroup_mkdir, + * TP_PROTO(struct cgroup *cgrp, const char *path), + * TP_ARGS(cgrp, path) + */ + +static struct __cgrps_kfunc_map_value *insert_lookup_cgrp(struct cgroup *cgrp) +{ + int status; + + status = cgrps_kfunc_map_insert(cgrp); + if (status) + return NULL; + + return cgrps_kfunc_map_value_lookup(cgrp); +} + +SEC("tp_btf/cgroup_mkdir") +__failure __msg("Possibly NULL pointer passed to trusted arg0") +int BPF_PROG(cgrp_kfunc_acquire_untrusted, struct cgroup *cgrp, const char *path) +{ + struct cgroup *acquired; + struct __cgrps_kfunc_map_value *v; + + v = insert_lookup_cgrp(cgrp); + if (!v) + return 0; + + /* Can't invoke bpf_cgroup_acquire() on an untrusted pointer. */ + acquired = bpf_cgroup_acquire(v->cgrp); + if (acquired) + bpf_cgroup_release(acquired); + + return 0; +} + +SEC("tp_btf/cgroup_mkdir") +__failure __msg("Possibly NULL pointer passed to trusted arg0") +int BPF_PROG(cgrp_kfunc_acquire_no_null_check, struct cgroup *cgrp, const char *path) +{ + struct cgroup *acquired; + + acquired = bpf_cgroup_acquire(cgrp); + /* + * Can't invoke bpf_cgroup_release() without checking the return value + * of bpf_cgroup_acquire(). + */ + bpf_cgroup_release(acquired); + + return 0; +} + +SEC("tp_btf/cgroup_mkdir") +__failure __msg("arg#0 pointer type STRUCT cgroup must point") +int BPF_PROG(cgrp_kfunc_acquire_fp, struct cgroup *cgrp, const char *path) +{ + struct cgroup *acquired, *stack_cgrp = (struct cgroup *)&path; + + /* Can't invoke bpf_cgroup_acquire() on a random frame pointer. */ + acquired = bpf_cgroup_acquire((struct cgroup *)&stack_cgrp); + if (acquired) + bpf_cgroup_release(acquired); + + return 0; +} + +SEC("kretprobe/cgroup_destroy_locked") +__failure __msg("calling kernel function bpf_cgroup_acquire is not allowed") +int BPF_PROG(cgrp_kfunc_acquire_unsafe_kretprobe, struct cgroup *cgrp) +{ + struct cgroup *acquired; + + /* Can't acquire an untrusted struct cgroup * pointer. */ + acquired = bpf_cgroup_acquire(cgrp); + if (acquired) + bpf_cgroup_release(acquired); + + return 0; +} + +SEC("tp_btf/cgroup_mkdir") +__failure __msg("cgrp_kfunc_acquire_trusted_walked") +int BPF_PROG(cgrp_kfunc_acquire_trusted_walked, struct cgroup *cgrp, const char *path) +{ + struct cgroup *acquired; + + /* Can't invoke bpf_cgroup_acquire() on a pointer obtained from walking a trusted cgroup. */ + acquired = bpf_cgroup_acquire(cgrp->old_dom_cgrp); + if (acquired) + bpf_cgroup_release(acquired); + + return 0; +} + +SEC("tp_btf/cgroup_mkdir") +__failure __msg("Possibly NULL pointer passed to trusted arg0") +int BPF_PROG(cgrp_kfunc_acquire_null, struct cgroup *cgrp, const char *path) +{ + struct cgroup *acquired; + + /* Can't invoke bpf_cgroup_acquire() on a NULL pointer. */ + acquired = bpf_cgroup_acquire(NULL); + if (acquired) + bpf_cgroup_release(acquired); + + return 0; +} + +SEC("tp_btf/cgroup_mkdir") +__failure __msg("Unreleased reference") +int BPF_PROG(cgrp_kfunc_acquire_unreleased, struct cgroup *cgrp, const char *path) +{ + struct cgroup *acquired; + + acquired = bpf_cgroup_acquire(cgrp); + + /* Acquired cgroup is never released. */ + __sink(acquired); + + return 0; +} + +SEC("tp_btf/cgroup_mkdir") +__failure __msg("Unreleased reference") +int BPF_PROG(cgrp_kfunc_xchg_unreleased, struct cgroup *cgrp, const char *path) +{ + struct cgroup *kptr; + struct __cgrps_kfunc_map_value *v; + + v = insert_lookup_cgrp(cgrp); + if (!v) + return 0; + + kptr = bpf_kptr_xchg(&v->cgrp, NULL); + if (!kptr) + return 0; + + /* Kptr retrieved from map is never released. */ + + return 0; +} + +SEC("tp_btf/cgroup_mkdir") +__failure __msg("must be referenced or trusted") +int BPF_PROG(cgrp_kfunc_rcu_get_release, struct cgroup *cgrp, const char *path) +{ + struct cgroup *kptr; + struct __cgrps_kfunc_map_value *v; + + v = insert_lookup_cgrp(cgrp); + if (!v) + return 0; + + bpf_rcu_read_lock(); + kptr = v->cgrp; + if (kptr) + /* Can't release a cgroup kptr stored in a map. */ + bpf_cgroup_release(kptr); + bpf_rcu_read_unlock(); + + return 0; +} + +SEC("tp_btf/cgroup_mkdir") +__failure __msg("Possibly NULL pointer passed to trusted arg0") +int BPF_PROG(cgrp_kfunc_release_untrusted, struct cgroup *cgrp, const char *path) +{ + struct __cgrps_kfunc_map_value *v; + + v = insert_lookup_cgrp(cgrp); + if (!v) + return 0; + + /* Can't invoke bpf_cgroup_release() on an untrusted pointer. */ + bpf_cgroup_release(v->cgrp); + + return 0; +} + +SEC("tp_btf/cgroup_mkdir") +__failure __msg("arg#0 pointer type STRUCT cgroup must point") +int BPF_PROG(cgrp_kfunc_release_fp, struct cgroup *cgrp, const char *path) +{ + struct cgroup *acquired = (struct cgroup *)&path; + + /* Cannot release random frame pointer. */ + bpf_cgroup_release(acquired); + + return 0; +} + +SEC("tp_btf/cgroup_mkdir") +__failure __msg("Possibly NULL pointer passed to trusted arg0") +int BPF_PROG(cgrp_kfunc_release_null, struct cgroup *cgrp, const char *path) +{ + struct __cgrps_kfunc_map_value local, *v; + long status; + struct cgroup *acquired, *old; + s32 id; + + status = bpf_probe_read_kernel(&id, sizeof(id), &cgrp->self.id); + if (status) + return 0; + + local.cgrp = NULL; + status = bpf_map_update_elem(&__cgrps_kfunc_map, &id, &local, BPF_NOEXIST); + if (status) + return status; + + v = bpf_map_lookup_elem(&__cgrps_kfunc_map, &id); + if (!v) + return -ENOENT; + + acquired = bpf_cgroup_acquire(cgrp); + if (!acquired) + return -ENOENT; + + old = bpf_kptr_xchg(&v->cgrp, acquired); + + /* old cannot be passed to bpf_cgroup_release() without a NULL check. */ + bpf_cgroup_release(old); + + return 0; +} + +SEC("tp_btf/cgroup_mkdir") +__failure __msg("release kernel function bpf_cgroup_release expects") +int BPF_PROG(cgrp_kfunc_release_unacquired, struct cgroup *cgrp, const char *path) +{ + /* Cannot release trusted cgroup pointer which was not acquired. */ + bpf_cgroup_release(cgrp); + + return 0; +} |