[PATCH v2] cpupower: Fix cpuidle_set to accept only numeric values for idle-set operation.

[Korrapati Likhitha <likhitha@linux.ibm.com>]

From: Likhitha Korrapati <likhitha@linux.ibm.com>

For both the d and e options in 'cpupower idle_set' command, an
atoi() conversion is done without checking if the input argument
is all numeric. So, an atoi conversion is done on any character
provided as input and the CPU idle_set operation continues with
that integer value, which may not be what is intended or entirely
correct.

The output of cpuidle-set before patch is as follows:

[root@xxx cpupower]# cpupower idle-set -e 1$
Idlestate 1 enabled on CPU 0
[snip]
Idlestate 1 enabled on CPU 47

[root@xxx cpupower]# cpupower idle-set -e 11
Idlestate 11 not available on CPU 0
[snip]
Idlestate 11 not available on CPU 47

[root@xxx cpupower]# cpupower idle-set -d 12
Idlestate 12 not available on CPU 0
[snip]
Idlestate 12 not available on CPU 47

[root@xxx cpupower]# cpupower idle-set -d qw
Idlestate 0 disabled on CPU 0
[snip]
Idlestate 0 disabled on CPU 47

This patch adds a check for both d and e options in cpuidle-set.c
to see that the idle_set value is all numeric before doing a
string-to-int conversion.

The output of cpuidle-set after the patch is as below:

[root@xxx cpupower]# ./cpupower idle-set -e 1$
Bad idle_set value: 1$. Integer expected

[root@xxx cpupower]# ./cpupower idle-set -e 11
Idlestate 11 not available on CPU 0
[snip]
Idlestate 11 not available on CPU 47

[root@xxx cpupower]# ./cpupower idle-set -d 12
Idlestate 12 not available on CPU 0
[snip]
Idlestate 12 not available on CPU 47

[root@xxx cpupower]# ./cpupower idle-set -d qw
Bad idle_set value: qw. Integer expected

Signed-off-by: Likhitha Korrapati <likhitha@linux.ibm.com>
Signed-off-by: Brahadambal Srinivasan <latha@linux.vnet.ibm.com>
Reported-by: Pavithra Prakash <pavrampu@linux.vnet.ibm.com>
Reviewed-by: Rick Lindsley <ricklind@linux.vnet.ibm.com>
---

** changes since v1 [1] **

- Addressed reviewed comments from v1.
- Slightly reworded the commit for clarity.

[1] https://lore.kernel.org/all/20210105122452.8687-1-latha@linux.vnet.ibm.com/

 tools/power/cpupower/utils/cpuidle-set.c     | 25 ++++++++++++++++----
 tools/power/cpupower/utils/helpers/helpers.h |  8 +++++++
 tools/power/cpupower/utils/helpers/misc.c    | 17 +++++++++++++
 3 files changed, 45 insertions(+), 5 deletions(-)

diff --git a/tools/power/cpupower/utils/cpuidle-set.c b/tools/power/cpupower/utils/cpuidle-set.c
index 46158928f9ad..1bfe16d27c2d 100644
--- a/tools/power/cpupower/utils/cpuidle-set.c
+++ b/tools/power/cpupower/utils/cpuidle-set.c
@@ -47,7 +47,12 @@ int cmd_idle_set(int argc, char **argv)
 				break;
 			}
 			param = ret;
-			idlestate = atoi(optarg);
+			if (is_stringnumeric(optarg))
+				idlestate = atoi(optarg);
+			else {
+				printf(_("Bad idle_set value: %s. Integer expected\n"), optarg);
+				exit(EXIT_FAILURE);
+			}
 			break;
 		case 'e':
 			if (param) {
@@ -56,7 +61,12 @@ int cmd_idle_set(int argc, char **argv)
 				break;
 			}
 			param = ret;
-			idlestate = atoi(optarg);
+			if (is_stringnumeric(optarg))
+				idlestate = atoi(optarg);
+			else {
+				printf(_("Bad idle_set value: %s. Integer expected\n"), optarg);
+				exit(EXIT_FAILURE);
+			}
 			break;
 		case 'D':
 			if (param) {
@@ -65,9 +75,14 @@ int cmd_idle_set(int argc, char **argv)
 				break;
 			}
 			param = ret;
-			latency = strtoull(optarg, &endptr, 10);
-			if (*endptr != '\0') {
-				printf(_("Bad latency value: %s\n"), optarg);
+			if (is_stringnumeric(optarg)) {
+				latency = strtoull(optarg, &endptr, 10);
+				if (*endptr != '\0') {
+					printf(_("Bad latency value: %s\n"), optarg);
+					exit(EXIT_FAILURE);
+				}
+			} else {
+				printf(_("Bad idle_set value: %s. Integer expected\n"), optarg);
 				exit(EXIT_FAILURE);
 			}
 			break;
diff --git a/tools/power/cpupower/utils/helpers/helpers.h b/tools/power/cpupower/utils/helpers/helpers.h
index 96e4bede078b..9977f0773986 100644
--- a/tools/power/cpupower/utils/helpers/helpers.h
+++ b/tools/power/cpupower/utils/helpers/helpers.h
@@ -208,3 +208,11 @@ void print_offline_cpus(void);
 void print_speed(unsigned long speed, int no_rounding);
 
 #endif /* __CPUPOWERUTILS_HELPERS__ */
+
+/*
+ * CPU idle-set
+ */
+int is_stringnumeric(char *arg);
+/*
+ * CPU idle-set
+ */
diff --git a/tools/power/cpupower/utils/helpers/misc.c b/tools/power/cpupower/utils/helpers/misc.c
index 9547b29254a7..8ec47c3c138e 100644
--- a/tools/power/cpupower/utils/helpers/misc.c
+++ b/tools/power/cpupower/utils/helpers/misc.c
@@ -4,6 +4,7 @@
 #include <errno.h>
 #include <stdlib.h>
 #include <string.h>
+#include <ctype.h>
 
 #include "helpers/helpers.h"
 #include "helpers/sysfs.h"
@@ -204,3 +205,19 @@ void print_speed(unsigned long speed, int no_rounding)
 		}
 	}
 }
+
+/*
+ * is_stringnumeric
+ *
+ * To check if the given string has all numericals
+ */
+int is_stringnumeric(char *arg)
+{
+	size_t i = 0;
+
+	for (i = 0; arg[i] ; i++) {
+		if (!isdigit(arg[i]))
+			return 0;
+	}
+	return 1;
+}
-- 
2.31.1