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Diffstat (limited to '')
-rw-r--r-- | tools/testing/selftests/bpf/progs/ima.c | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/ima.c b/tools/testing/selftests/bpf/progs/ima.c new file mode 100644 index 000000000..e16a2c208 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/ima.c @@ -0,0 +1,103 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * Copyright 2020 Google LLC. + */ + +#include "vmlinux.h" +#include <errno.h> +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.h> + +u32 monitored_pid = 0; + +struct { + __uint(type, BPF_MAP_TYPE_RINGBUF); + __uint(max_entries, 1 << 12); +} ringbuf SEC(".maps"); + +char _license[] SEC("license") = "GPL"; + +bool use_ima_file_hash; +bool enable_bprm_creds_for_exec; +bool enable_kernel_read_file; +bool test_deny; + +static void ima_test_common(struct file *file) +{ + u64 ima_hash = 0; + u64 *sample; + int ret; + u32 pid; + + pid = bpf_get_current_pid_tgid() >> 32; + if (pid == monitored_pid) { + if (!use_ima_file_hash) + ret = bpf_ima_inode_hash(file->f_inode, &ima_hash, + sizeof(ima_hash)); + else + ret = bpf_ima_file_hash(file, &ima_hash, + sizeof(ima_hash)); + if (ret < 0 || ima_hash == 0) + return; + + sample = bpf_ringbuf_reserve(&ringbuf, sizeof(u64), 0); + if (!sample) + return; + + *sample = ima_hash; + bpf_ringbuf_submit(sample, 0); + } + + return; +} + +static int ima_test_deny(void) +{ + u32 pid; + + pid = bpf_get_current_pid_tgid() >> 32; + if (pid == monitored_pid && test_deny) + return -EPERM; + + return 0; +} + +SEC("lsm.s/bprm_committed_creds") +void BPF_PROG(bprm_committed_creds, struct linux_binprm *bprm) +{ + ima_test_common(bprm->file); +} + +SEC("lsm.s/bprm_creds_for_exec") +int BPF_PROG(bprm_creds_for_exec, struct linux_binprm *bprm) +{ + if (!enable_bprm_creds_for_exec) + return 0; + + ima_test_common(bprm->file); + return 0; +} + +SEC("lsm.s/kernel_read_file") +int BPF_PROG(kernel_read_file, struct file *file, enum kernel_read_file_id id, + bool contents) +{ + int ret; + + if (!enable_kernel_read_file) + return 0; + + if (!contents) + return 0; + + if (id != READING_POLICY) + return 0; + + ret = ima_test_deny(); + if (ret < 0) + return ret; + + ima_test_common(file); + return 0; +} |