s390/pai: Prevent invalid event number for pai_crypto PMU

The pai_crypto PMU has to check the event number. It has to be in
the supported range. This is not the case, the lower limit is not
checked. Fix this and obey the lower limit.

Fixes: 39d6233 ("s390/pai: add support for cryptography counters")

Signed-off-by: Thomas Richter <[email protected]>
Suggested-by: Sumanth Korikkar <[email protected]>
Reviewed-by: Sumanth Korikkar <[email protected]>
Signed-off-by: Alexander Gordeev <[email protected]>

Author: Thomas Richter

arch/s390/kernel/perf_pai_crypto.c

@@ -193,8 +193,9 @@ static int paicrypt_event_init(struct perf_event *event)
 	/* PAI crypto PMU registered as PERF_TYPE_RAW, check event type */
 	if (a->type != PERF_TYPE_RAW && event->pmu->type != a->type)
 		return -ENOENT;
-	/* PAI crypto event must be valid */
-	if (a->config > PAI_CRYPTO_BASE + paicrypt_cnt)
+	/* PAI crypto event must be in valid range */
+	if (a->config < PAI_CRYPTO_BASE ||
+	    a->config > PAI_CRYPTO_BASE + paicrypt_cnt)
 		return -EINVAL;
 	/* Allow only CPU wide operation, no process context for now. */
 	if (event->hw.target || event->cpu == -1)