[PATCH v3 3/5] ima_violations.sh: additional open-writer violation tests

[Mimi Zohar <zohar@linux.ibm.com>]

Kernel patch "ima: limit the number of open-writers integrity
violations" prevents superfluous "open-writers" violations.  Add
corresponding LTP tests.

Link: https://lore.kernel.org/linux-integrity/20250228205505.476845-2-zohar@linux.ibm.com/
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
---
 .../integrity/ima/tests/ima_violations.sh     | 87 ++++++++++++++++++-
 1 file changed, 86 insertions(+), 1 deletion(-)

diff --git a/testcases/kernel/security/integrity/ima/tests/ima_violations.sh b/testcases/kernel/security/integrity/ima/tests/ima_violations.sh
index 37bf2182b..d3081a4d1 100755
--- a/testcases/kernel/security/integrity/ima/tests/ima_violations.sh
+++ b/testcases/kernel/security/integrity/ima/tests/ima_violations.sh
@@ -8,7 +8,7 @@
 
 TST_SETUP="setup"
 TST_CLEANUP="cleanup"
-TST_CNT=3
+TST_CNT=6
 
 REQUIRED_BUILTIN_POLICY="tcb"
 REQUIRED_POLICY_CONTENT='violations.policy'
@@ -61,6 +61,17 @@ close_file_write()
 	exec 4>&-
 }
 
+open_file_write2()
+{
+	exec 5> $FILE || tst_brk TBROK "exec 5> $FILE failed"
+	echo 'test writing2' >&5
+}
+
+close_file_write2()
+{
+	exec 5>&-
+}
+
 get_count()
 {
 	local search="$1"
@@ -162,6 +173,80 @@ test3()
 	tst_sleep 2s
 }
 
+test4()
+{
+	tst_res TINFO "verify limiting single open writer violation"
+
+	local search="open_writers"
+	local count num_violations
+
+	read num_violations < $IMA_VIOLATIONS
+	count="$(get_count $search)"
+
+	open_file_write
+	open_file_read
+	close_file_read
+
+	open_file_read
+	close_file_read
+
+	close_file_write
+
+	validate "$num_violations" "$count" "$search" 1
+}
+
+test5()
+{
+	tst_res TINFO "verify limiting multiple open writers violations"
+
+	local search="open_writers"
+	local count num_violations
+
+	read num_violations < $IMA_VIOLATIONS
+	count="$(get_count $search)"
+
+	open_file_write
+	open_file_read
+	close_file_read
+
+	open_file_write2
+	open_file_read
+	close_file_read
+	close_file_write2
+
+	open_file_read
+	close_file_read
+
+	close_file_write
+
+	validate "$num_violations" "$count" "$search" 1
+}
+
+test6()
+{
+	tst_res TINFO "verify new open writer causes additional violation"
+
+	local search="open_writers"
+	local count num_violations
+
+	read num_violations < $IMA_VIOLATIONS
+	count="$(get_count $search)"
+
+	open_file_write
+	open_file_read
+	close_file_read
+
+	open_file_read
+	close_file_read
+	close_file_write
+
+	open_file_write
+	open_file_read
+	close_file_read
+	close_file_write
+	validate "$num_violations" "$count" "$search" 2
+}
+
 . ima_setup.sh
 . daemonlib.sh
 tst_run
-- 
2.48.1