diff options
author | KP Singh <kpsingh@google.com> | 2020-11-24 15:12:10 +0000 |
---|---|---|
committer | Daniel Borkmann <daniel@iogearbox.net> | 2020-11-26 00:25:47 +0100 |
commit | 34b82d3ac1058653b3de7be4697b55f67533b1f1 (patch) | |
tree | 446d0619ca0cf5c22e8698e90f92f908170e8879 /tools/testing/selftests/bpf/progs/ima.c | |
parent | 27672f0d280a3f286a410a8db2004f46ace72a17 (diff) |
bpf: Add a selftest for bpf_ima_inode_hash
The test does the following:
- Mounts a loopback filesystem and appends the IMA policy to measure
executions only on this file-system. Restricting the IMA policy to
a particular filesystem prevents a system-wide IMA policy change.
- Executes an executable copied to this loopback filesystem.
- Calls the bpf_ima_inode_hash in the bprm_committed_creds hook and
checks if the call succeeded and checks if a hash was calculated.
The test shells out to the added ima_setup.sh script as the setup is
better handled in a shell script and is more complicated to do in the
test program or even shelling out individual commands from C.
The list of required configs (i.e. IMA, SECURITYFS,
IMA_{WRITE,READ}_POLICY) for running this test are also updated.
Suggested-by: Mimi Zohar <zohar@linux.ibm.com> (limit policy rule to loopback mount)
Signed-off-by: KP Singh <kpsingh@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20201124151210.1081188-4-kpsingh@chromium.org
Diffstat (limited to 'tools/testing/selftests/bpf/progs/ima.c')
-rw-r--r-- | tools/testing/selftests/bpf/progs/ima.c | 28 |
1 files changed, 28 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 000000000000..86b21aff4bc5 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/ima.c @@ -0,0 +1,28 @@ +// 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> + +long ima_hash_ret = -1; +u64 ima_hash = 0; +u32 monitored_pid = 0; + +char _license[] SEC("license") = "GPL"; + +SEC("lsm.s/bprm_committed_creds") +int BPF_PROG(ima, struct linux_binprm *bprm) +{ + u32 pid = bpf_get_current_pid_tgid() >> 32; + + if (pid == monitored_pid) + ima_hash_ret = bpf_ima_inode_hash(bprm->file->f_inode, + &ima_hash, sizeof(ima_hash)); + + return 0; +} |