From: Martin KaFai Lau <martin.lau@xxxxxxxxxx> Add verifier tests to ensure invalid uptr usages are rejected. Signed-off-by: Martin KaFai Lau <martin.lau@xxxxxxxxxx> --- .../bpf/prog_tests/task_local_storage.c | 2 + .../selftests/bpf/progs/uptr_failure.c | 105 ++++++++++++++++++ 2 files changed, 107 insertions(+) create mode 100644 tools/testing/selftests/bpf/progs/uptr_failure.c diff --git a/tools/testing/selftests/bpf/prog_tests/task_local_storage.c b/tools/testing/selftests/bpf/prog_tests/task_local_storage.c index e985665efe7a..772ed7ce4feb 100644 --- a/tools/testing/selftests/bpf/prog_tests/task_local_storage.c +++ b/tools/testing/selftests/bpf/prog_tests/task_local_storage.c @@ -18,6 +18,7 @@ #include "uptr_test_common.h" #include "task_ls_uptr.skel.h" #include "uptr_update_failure.skel.h" +#include "uptr_failure.skel.h" static void test_sys_enter_exit(void) { @@ -467,4 +468,5 @@ void test_task_local_storage(void) test_uptr_across_pages(); if (test__start_subtest("uptr_update_failure")) test_uptr_update_failure(); + RUN_TESTS(uptr_failure); } diff --git a/tools/testing/selftests/bpf/progs/uptr_failure.c b/tools/testing/selftests/bpf/progs/uptr_failure.c new file mode 100644 index 000000000000..0cfa1fd61440 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/uptr_failure.c @@ -0,0 +1,105 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */ + +#include <vmlinux.h> +#include <bpf/bpf_helpers.h> +#include "bpf_experimental.h" +#include "bpf_misc.h" +#include "uptr_test_common.h" + +struct { + __uint(type, BPF_MAP_TYPE_TASK_STORAGE); + __uint(map_flags, BPF_F_NO_PREALLOC); + __type(key, int); + __type(value, struct value_type); +} datamap SEC(".maps"); + +SEC("?syscall") +__failure __msg("store to uptr disallowed") +int uptr_write(const void *ctx) +{ + struct task_struct *task; + struct value_type *v; + + task = bpf_get_current_task_btf(); + v = bpf_task_storage_get(&datamap, task, 0, + BPF_LOCAL_STORAGE_GET_F_CREATE); + if (!v) + return 0; + + v->udata = NULL; + return 0; +} + +SEC("?syscall") +__failure __msg("store to uptr disallowed") +int uptr_write_nested(const void *ctx) +{ + struct task_struct *task; + struct value_type *v; + + task = bpf_get_current_task_btf(); + v = bpf_task_storage_get(&datamap, task, 0, + BPF_LOCAL_STORAGE_GET_F_CREATE); + if (!v) + return 0; + + v->nested.udata = NULL; + return 0; +} + +SEC("?syscall") +__failure __msg("R1 invalid mem access 'mem_or_null'") +int uptr_no_null_check(const void *ctx) +{ + struct task_struct *task; + struct value_type *v; + + task = bpf_get_current_task_btf(); + v = bpf_task_storage_get(&datamap, task, 0, + BPF_LOCAL_STORAGE_GET_F_CREATE); + if (!v) + return 0; + + v->udata->result = 0; + + return 0; +} + +SEC("?syscall") +__failure __msg("doesn't point to kptr") +int uptr_kptr_xchg(const void *ctx) +{ + struct task_struct *task; + struct value_type *v; + + task = bpf_get_current_task_btf(); + v = bpf_task_storage_get(&datamap, task, 0, + BPF_LOCAL_STORAGE_GET_F_CREATE); + if (!v) + return 0; + + bpf_kptr_xchg(&v->udata, NULL); + + return 0; +} + +SEC("?syscall") +__failure __msg("invalid mem access 'scalar'") +int uptr_obj_new(const void *ctx) +{ + struct value_type *v; + + v = bpf_obj_new(typeof(*v)); + if (!v) + return 0; + + if (v->udata) + v->udata->result = 0; + + bpf_obj_drop(v); + + return 0; +} + +char _license[] SEC("license") = "GPL"; -- 2.43.5