Make sure that the bulk-out buffers are at least as large as the
hardcoded transfer size to avoid user-controlled slab corruption should
a malicious device report a smaller endpoint max packet size than
expected.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/usb/serial/omninet.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/serial/omninet.c b/drivers/usb/serial/omninet.c
index aa1e9745f967..b59982ed8b25 100644
--- a/drivers/usb/serial/omninet.c
+++ b/drivers/usb/serial/omninet.c
@@ -30,6 +30,10 @@
 /* This one seems to be a re-branded ZyXEL device */
 #define BT_IGNITIONPRO_ID	0x2000
 
+#define OMNINET_HEADERLEN	4
+#define OMNINET_BULKOUTSIZE	64
+#define OMNINET_PAYLOADSIZE	(OMNINET_BULKOUTSIZE - OMNINET_HEADERLEN)
+
 /* function prototypes */
 static void omninet_process_read_urb(struct urb *urb);
 static int omninet_prepare_write_buffer(struct usb_serial_port *port,
@@ -54,6 +58,7 @@ static struct usb_serial_driver zyxel_omninet_device = {
 	.description =		"ZyXEL - omni.net usb",
 	.id_table =		id_table,
 	.num_bulk_out =		2,
+	.bulk_out_size =	OMNINET_BULKOUTSIZE,
 	.calc_num_ports =	omninet_calc_num_ports,
 	.port_probe =		omninet_port_probe,
 	.port_remove =		omninet_port_remove,
@@ -130,10 +135,6 @@ static void omninet_port_remove(struct usb_serial_port *port)
 	kfree(od);
 }
 
-#define OMNINET_HEADERLEN	4
-#define OMNINET_BULKOUTSIZE	64
-#define OMNINET_PAYLOADSIZE	(OMNINET_BULKOUTSIZE - OMNINET_HEADERLEN)
-
 static void omninet_process_read_urb(struct urb *urb)
 {
 	struct usb_serial_port *port = urb->context;
-- 
2.53.0

On Fri, May 22, 2026 at 04:20:58PM +0200, Johan Hovold wrote:
> Make sure that the bulk-out buffers are at least as large as the
> hardcoded transfer size to avoid user-controlled slab corruption should
> a malicious device report a smaller endpoint max packet size than
> expected.
> 
> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> Cc: stable@vger.kernel.org
> Signed-off-by: Johan Hovold <johan@kernel.org>
> ---
>  drivers/usb/serial/omninet.c | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>