[PATCH] pktcdvd: Fix overflow for discs with large packets

The pktcdvd driver was using an 8 bit field to store the packet length
obtained from the disc track info.  This causes it to overflow packet length
values of 128KB or more.  I changed the field to 32 bits to fix this.

The pktcdvd driver defaulted to its maximum allowed packet length when it
detected a 0 in the track info field.  I changed this to fail the operation
and refuse to access the media.  This seems more sane than attempting to
access it with a value that almost certainly will not work.

Signed-off-by: Peter Osterlund <petero2@telia.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 2 insertions, 2 deletions

diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index 93affeeef7bd..d95e7e1ac355 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -1639,7 +1639,7 @@ static int pkt_probe_settings(struct pktcdvd_device *pd)
         pd->settings.size = be32_to_cpu(ti.fixed_packet_size) << 2;
         if (pd->settings.size == 0) {
                 printk("pktcdvd: detected zero packet size!\n");
-                pd->settings.size = 128;
+                return -ENXIO;
         }
         if (pd->settings.size > PACKET_MAX_SECTORS) {
                 printk("pktcdvd: packet size is too big\n");
diff --git a/include/linux/pktcdvd.h b/include/linux/pktcdvd.h
index 2c177e4c8f22..d1c9c4a86e52 100644
--- a/include/linux/pktcdvd.h
+++ b/include/linux/pktcdvd.h
@@ -114,7 +114,7 @@ struct pkt_ctrl_command {
 
 struct packet_settings
 {
-        __u8                    size;           /* packet size in (512 byte) sectors */
+        __u32                   size;           /* packet size in (512 byte) sectors */
         __u8                    fp;             /* fixed packets */
         __u8                    link_loss;      /* the rest is specified
                                                  * as per Mt Fuji */