[LTP] [PATCH v3 6/6] ima/ima_violations: Temporarily remove the printk rate limit

Mimi Zohar
2019-01-20T18:38:54Z

On Wed, 2019-01-16 at 10:57 +0800, Jia Zhang wrote:
> The output frequency of audit log is limited by printk_ratelimit()
> in kernel if auditd not used. Thus, the test cases heavily depending
> on searching certain keywords in log file may fail if the matching
> patterns are exactly suppressed by printk_ratelimit().
>
> In order to fix such a sort of failure, just temporarily remove the
> printk rate limit, and restore its original setting when doing
> cleanup.
>
> Signed-off-by: Jia Zhang <zhang.jia@linux.alibaba.com>

Thanks, I wasn't aware of the sysctl. Â If the message isn't in
/var/log/messages or /var/log/audit/audit.log, do we now need to also
check journalctl?

Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>

> ---
> .../kernel/security/integrity/ima/tests/ima_setup.sh | 2 +-
> .../kernel/security/integrity/ima/tests/ima_violations.sh | 15 +++++++++++++++
> 2 files changed, 16 insertions(+), 1 deletion(-)
>
> diff --git a/testcases/kernel/security/integrity/ima/tests/ima_setup.sh b/testcases/kernel/security/integrity/ima/tests/ima_setup.sh
> index 6dfb4d2..fe60981 100644
> --- a/testcases/kernel/security/integrity/ima/tests/ima_setup.sh
> +++ b/testcases/kernel/security/integrity/ima/tests/ima_setup.sh
> @@ -20,7 +20,7 @@
> TST_TESTFUNC="test"
> TST_SETUP_CALLER="$TST_SETUP"
> TST_SETUP="ima_setup"
> -TST_CLEANUP="ima_cleanup"
> +TST_CLEANUP="${TST_CLEANUP:-ima_cleanup}"
> TST_NEEDS_TMPDIR=1
> TST_NEEDS_ROOT=1
>
> diff --git a/testcases/kernel/security/integrity/ima/tests/ima_violations.sh b/testcases/kernel/security/integrity/ima/tests/ima_violations.sh
> index f3f40d4..74223c2 100755
> --- a/testcases/kernel/security/integrity/ima/tests/ima_violations.sh
> +++ b/testcases/kernel/security/integrity/ima/tests/ima_violations.sh
> @@ -20,6 +20,7 @@
> # Test whether ToMToU and open_writer violations invalidatethe PCR and are logged.
>
> TST_SETUP="setup"
> +TST_CLEANUP="cleanup"
> TST_CNT=3
> TST_NEEDS_DEVICE=1
>
> @@ -31,15 +32,29 @@ setup()
> FILE="test.txt"
> IMA_VIOLATIONS="$SECURITYFS/ima/violations"
> LOG="/var/log/messages"
> + PRINTK_RATE_LIMIT="0"
>
> if status_daemon auditd; then
> LOG="/var/log/audit/audit.log"
> + else
> + tst_check_cmds sysctl
> +
> + PRINTK_RATE_LIMIT=`sysctl -n kernel.printk_ratelimit`
> + sysctl -wq kernel.printk_ratelimit=0
> fi
> [ -f "$LOG" ] || \
> tst_brk TBROK "log $LOG does not exist (bug in detection?)"
> tst_res TINFO "using log $LOG"
> }
>
> +cleanup()
> +{
> + [ "$PRINTK_RATE_LIMIT" != "0" ] && \
> + sysctl -wq kernel.printk_ratelimit=$PRINTK_RATE_LIMIT
> +
> + ima_cleanup
> +}
> +
> open_file_read()
> {
> exec 3< $FILE || exit 1