[PATCH] pcmcia: Read buffer overflow

[Roel Kluin]

if count > 0  and dev->rlen == dev->rpos and dev->proto == 0
then we read and write dev->rbuf[-1];

Signed-off-by: Roel Kluin <roel.kluin at gmail.com>
---
Unless I am mistaken, so please review

diff --git a/drivers/char/pcmcia/cm4000_cs.c b/drivers/char/pcmcia/cm4000_cs.c
index 881934c..c250a31 100644
--- a/drivers/char/pcmcia/cm4000_cs.c
+++ b/drivers/char/pcmcia/cm4000_cs.c
@@ -1017,7 +1017,7 @@ static ssize_t cmm_read(struct file *filp, __user char *buf, size_t count,
 		}
 	}
 
-	if (dev->proto == 0 && count > dev->rlen - dev->rpos) {
+	if (dev->proto == 0 && count > dev->rlen - dev->rpos && i) {
 		DEBUGP(4, dev, "T=0 and count > buffer\n");
 		dev->rbuf[i] = dev->rbuf[i - 1];
 		dev->rbuf[i - 1] = dev->procbyte;