[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, 2 deletions

diff --git a/drivers/media/dvb/frontends/or51211.c b/drivers/media/dvb/frontends/or51211.c
index 8a9db23dd1b7..531f76246e5f 100644
--- a/drivers/media/dvb/frontends/or51211.c
+++ b/drivers/media/dvb/frontends/or51211.c
@@ -339,6 +339,7 @@ static int or51211_read_signal_strength(struct dvb_frontend* fe, u16* strength)
         u8 rec_buf[2];
         u8 snd_buf[4];
         u8 snr_equ;
+        u32 signal_strength;
 
         /* SNR after Equalizer */
         snd_buf[0] = 0x04;
@@ -358,8 +359,11 @@ static int or51211_read_signal_strength(struct dvb_frontend* fe, u16* strength)
         snr_equ = rec_buf[0] & 0xff;
 
         /* The value reported back from the frontend will be FFFF=100% 0000=0% */
-        *strength = (((5334 - i20Log10(snr_equ))/3+5)*65535)/1000;
-
+        signal_strength = (((5334 - i20Log10(snr_equ))/3+5)*65535)/1000;
+        if (signal_strength > 0xffff)
+                *strength = 0xffff;
+        else
+                *strength = signal_strength;
         dprintk("read_signal_strength %i\n",*strength);
 
         return 0;