[PATCH v3 07/12] [media] ddbridge: fix possible buffer overflow in ddb_ports_init()

[Daniel Scheller]

From: Daniel Scheller <d.schel...@gmx.net>

Report from smatch:

  drivers/media/pci/ddbridge/ddbridge-core.c:2659 ddb_ports_init() error: 
buffer overflow 'dev->port' 32 <= u32max

Fix by making sure "p" is greater than zero before checking for
"dev->port[].type == DDB_CI_EXTERNAL_XO2".

Cc: Ralph Metzler <r...@metzlerbros.de>
Signed-off-by: Daniel Scheller <d.schel...@gmx.net>
Tested-by: Richard Scobie <r.sco...@clear.net.nz>
Tested-by: Jasmin Jessich <jas...@anw.at>
Tested-by: Dietmar Spingler <d_sping...@freenet.de>
Tested-by: Manfred Knick <manfred.kn...@t-online.de>
---
 drivers/media/pci/ddbridge/ddbridge-core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/pci/ddbridge/ddbridge-core.c 
b/drivers/media/pci/ddbridge/ddbridge-core.c
index d01d54159008..2a4bb6ddf3a2 100644
--- a/drivers/media/pci/ddbridge/ddbridge-core.c
+++ b/drivers/media/pci/ddbridge/ddbridge-core.c
@@ -2551,7 +2551,7 @@ void ddb_ports_init(struct ddb *dev)
                        port->dvb[0].adap = &dev->adap[2 * p];
                        port->dvb[1].adap = &dev->adap[2 * p + 1];
 
-                       if ((port->class == DDB_PORT_NONE) && i &&
+                       if ((port->class == DDB_PORT_NONE) && i && p &&
                            dev->port[p - 1].type == DDB_CI_EXTERNAL_XO2) {
                                port->class = DDB_PORT_CI;
                                port->type = DDB_CI_EXTERNAL_XO2_B;
-- 
2.13.0