vt: keyboard: avoid signed integer overflow in k_ascii

[platform/kernel/linux-starfive.git] / drivers / tty / vt / keyboard.c

diff --git a/drivers/tty/vt/keyboard.c b/drivers/tty/vt/keyboard.c
index 15d33fa..568b217 100644 (file)
--- a/drivers/tty/vt/keyboard.c
+++ b/drivers/tty/vt/keyboard.c
@@ -127,7 +127,11 @@ static DEFINE_SPINLOCK(func_buf_lock); /* guard 'func_buf'  and friends */
 static unsigned long key_down[BITS_TO_LONGS(KEY_CNT)]; /* keyboard key bitmap */
 static unsigned char shift_down[NR_SHIFT];             /* shift state counters.. */
 static bool dead_key_next;
-static int npadch = -1;                                        /* -1 or number assembled on pad */
+
+/* Handles a number being assembled on the number pad */
+static bool npadch_active;
+static unsigned int npadch_value;
+
 static unsigned int diacr;
 static char rep;                                       /* flag telling character repeat */
 
@@ -845,12 +849,12 @@ static void k_shift(struct vc_data *vc, unsigned char value, char up_flag)
                shift_state &= ~(1 << value);
 
        /* kludge */
-       if (up_flag && shift_state != old_state && npadch != -1) {
+       if (up_flag && shift_state != old_state && npadch_active) {
                if (kbd->kbdmode == VC_UNICODE)
-                       to_utf8(vc, npadch);
+                       to_utf8(vc, npadch_value);
                else
-                       put_queue(vc, npadch & 0xff);
-               npadch = -1;
+                       put_queue(vc, npadch_value & 0xff);
+               npadch_active = false;
        }
 }
 
@@ -868,7 +872,7 @@ static void k_meta(struct vc_data *vc, unsigned char value, char up_flag)
 
 static void k_ascii(struct vc_data *vc, unsigned char value, char up_flag)
 {
-       int base;
+       unsigned int base;
 
        if (up_flag)
                return;
@@ -882,10 +886,12 @@ static void k_ascii(struct vc_data *vc, unsigned char value, char up_flag)
                base = 16;
        }
 
-       if (npadch == -1)
-               npadch = value;
-       else
-               npadch = npadch * base + value;
+       if (!npadch_active) {
+               npadch_value = 0;
+               npadch_active = true;
+       }
+
+       npadch_value = npadch_value * base + value;
 }
 
 static void k_lock(struct vc_data *vc, unsigned char value, char up_flag)