Instead of using shared global variables between userspace and BPF, use
the ring buffer to send the IMA hash on the BPF ring buffer. This helps
in validating both IMA and the usage of the ringbuffer in sleepable
programs.
Signed-off-by: KP Singh <kpsingh@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210204193622.3367275-3-kpsingh@kernel.org
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
