1 files changed, 20 insertions, 4 deletions

diff --git a/drivers/acpi/processor_throttling.c b/drivers/acpi/processor_throttling.c
index 8728782aad3b..53345dbc5027 100644
--- a/drivers/acpi/processor_throttling.c
+++ b/drivers/acpi/processor_throttling.c
@@ -1232,7 +1232,10 @@ static ssize_t acpi_processor_write_throttling(struct file *file,
         int result = 0;
         struct seq_file *m = file->private_data;
         struct acpi_processor *pr = m->private;
-        char state_string[12] = { '\0' };
+        char state_string[5] = "";
+        char *charp = NULL;
+        size_t state_val = 0;
+        char tmpbuf[5] = "";
 
         if (!pr || (count > sizeof(state_string) - 1))
                 return -EINVAL;
@@ -1241,10 +1244,23 @@ static ssize_t acpi_processor_write_throttling(struct file *file,
                 return -EFAULT;
 
         state_string[count] = '\0';
+        if ((count > 0) && (state_string[count-1] == '\n'))
+                state_string[count-1] = '\0';
 
-        result = acpi_processor_set_throttling(pr,
-                                               simple_strtoul(state_string,
-                                                              NULL, 0));
+        charp = state_string;
+        if ((state_string[0] == 't') || (state_string[0] == 'T'))
+                charp++;
+
+        state_val = simple_strtoul(charp, NULL, 0);
+        if (state_val >= pr->throttling.state_count)
+                return -EINVAL;
+
+        snprintf(tmpbuf, 5, "%d", state_val);
+
+        if (strcmp(tmpbuf, charp) != 0)
+                return -EINVAL;
+
+        result = acpi_processor_set_throttling(pr, state_val);
         if (result)
                 return result;