[PATCH] dvb: Fix integer overflow bug

Fix integer overflow bug in read_signal_strength() reported by Anthony
Leclerc.

Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 6 insertions, 1 deletions

diff --git a/drivers/media/dvb/frontends/or51132.c b/drivers/media/dvb/frontends/or51132.c
index fc74c40d6477..78bded861d02 100644
--- a/drivers/media/dvb/frontends/or51132.c
+++ b/drivers/media/dvb/frontends/or51132.c
@@ -468,6 +468,7 @@ static int or51132_read_signal_strength(struct dvb_frontend* fe, u16* strength)
         unsigned char snd_buf[2];
         u8 rcvr_stat;
         u16 snr_equ;
+        u32 signal_strength;
         int usK;
 
         snd_buf[0]=0x04;
@@ -503,7 +504,11 @@ static int or51132_read_signal_strength(struct dvb_frontend* fe, u16* strength)
         usK = (rcvr_stat & 0x10) ? 3 : 0;
 
         /* The value reported back from the frontend will be FFFF=100% 0000=0% */
-        *strength = (((8952 - i20Log10(snr_equ) - usK*100)/3+5)*65535)/1000;
+        signal_strength = (((8952 - i20Log10(snr_equ) - usK*100)/3+5)*65535)/1000;
+        if (signal_strength > 0xffff)
+                *strength = 0xffff;
+        else
+                *strength = signal_strength;
         dprintk("read_signal_strength %i\n",*strength);
 
         return 0;