[PATCH 1/5] pktcdvd: Fix overflow for discs with large packets

[Peter Osterlund <petero2@telia.com>]

From: Phillip Susi <psusi@cfl.rr.com>

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>
---

 drivers/block/pktcdvd.c |    2 +-
 include/linux/pktcdvd.h |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index 81ad466..f0a0ad4 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -1640,7 +1640,7 @@ static int pkt_probe_settings(struct pkt
 	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 2c177e4..d1c9c4a 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 */
-- 
Peter Osterlund - petero2@telia.com
http://web.telia.com/~u89404340