7 Commits

Author SHA1 Message Date
Roberto Sassu
e6dcf7bbf3 selftests/bpf: Add test for bpf_lsm_kernel_read_file()
Test the ability of bpf_lsm_kernel_read_file() to call the sleepable
functions bpf_ima_inode_hash() or bpf_ima_file_hash() to obtain a
measurement of a loaded IMA policy.

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220302111404.193900-9-roberto.sassu@huawei.com
2022-03-10 18:57:55 -08:00
Roberto Sassu
91e8fa254d selftests/bpf: Check if the digest is refreshed after a file write
Verify that bpf_ima_inode_hash() returns a non-fresh digest after a file
write, and that bpf_ima_file_hash() returns a fresh digest. Verification is
done by requesting the digest from the bprm_creds_for_exec hook, called
before ima_bprm_check().

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220302111404.193900-7-roberto.sassu@huawei.com
2022-03-10 18:57:54 -08:00
KP Singh
b4fe9fec51 selftests/bpf: Silence ima_setup.sh when not running in verbose mode.
Currently, ima_setup.sh spews outputs from commands like mkfs and dd
on the terminal without taking into account the verbosity level of
the test framework. Update test_progs to set the environment variable
SELFTESTS_VERBOSE=1 when a verbose output is requested. This
environment variable is then used by ima_setup.sh (and can be used by
other similar scripts) to obey the verbosity level of the test harness
without needing to re-implement command line options for verbosity.

In "silent" mode, the script saves the output to a temporary file, the
contents of which are echoed back to stderr when the script encounters
an error.

Fixes: 34b82d3ac105 ("bpf: Add a selftest for bpf_ima_inode_hash")
Reported-by: Andrii Nakryiko <andrii@kernel.org>
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: KP Singh <kpsingh@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201211010711.3716917-1-kpsingh@kernel.org
2020-12-10 22:14:32 -08:00
KP Singh
ffebecd9d4 selftests/bpf: Indent ima_setup.sh with tabs.
The file was formatted with spaces instead of tabs and went unnoticed
as checkpatch.pl did not complain (probably because this is a shell
script). Re-indent it with tabs to be consistent with other scripts.

Signed-off-by: KP Singh <kpsingh@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201203191437.666737-5-kpsingh@chromium.org
2020-12-03 11:20:21 -08:00
KP Singh
1ee076719d selftests/bpf: Ensure securityfs mount before writing ima policy
SecurityFS may not be mounted even if it is enabled in the kernel
config. So, check if the mount exists in /proc/mounts by parsing the
file and, if not, mount it on /sys/kernel/security.

Fixes: 34b82d3ac105 ("bpf: Add a selftest for bpf_ima_inode_hash")
Reported-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: KP Singh <kpsingh@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201203191437.666737-3-kpsingh@chromium.org
2020-12-03 11:20:21 -08:00
KP Singh
3db980449b selftests/bpf: Update ima_setup.sh for busybox
losetup on busybox does not output the name of loop device on using
-f with --show. It also doesn't support -j to find the loop devices
for a given backing file. losetup is updated to use "-a" which is
available on busybox.

blkid does not support options (-s and -o) to only display the uuid, so
parse the output instead.

Not all environments have mkfs.ext4, the test requires a loop device
with a backing image file which could formatted with any filesystem.
Update to using mkfs.ext2 which is available on busybox.

Fixes: 34b82d3ac105 ("bpf: Add a selftest for bpf_ima_inode_hash")
Reported-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: KP Singh <kpsingh@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201203191437.666737-2-kpsingh@chromium.org
2020-12-03 11:20:20 -08:00
KP Singh
34b82d3ac1 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
2020-11-26 00:25:47 +01:00