Most Siano devices require an alignment for the response.

Changeset f3be52b0056a ("media: usb: siano: Fix general protection fault in smsusb") changed the logic with gets such aligment, but it now produces a sparce warning:

drivers/media/usb/siano/smsusb.c: In function 'smsusb_init_device': drivers/media/usb/siano/smsusb.c:447:37: warning: 'in_maxp' may be used uninitialized in this function [-Wmaybe-uninitialized] 447 | dev->response_alignment = in_maxp - sizeof(struct sms_msg_hdr); | ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

The sparse message itself is bogus, but a broken (or fake) USB eeprom could produce a negative value for response_alignment.

So, change the code in order to check if the result is not negative.

Fixes: f3be52b0056a ("media: usb: siano: Fix general protection fault in smsusb") CC: stable@vger.kernel.org Signed-off-by: Mauro Carvalho Chehab mchehab+samsung@kernel.org ---

Greg,

As the Alan patches went via your tree, please apply this one too.

drivers/media/usb/siano/smsusb.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/media/usb/siano/smsusb.c b/drivers/media/usb/siano/smsusb.c index f5e69fdf1242..9ba3a2ae36e5 100644 --- a/drivers/media/usb/siano/smsusb.c +++ b/drivers/media/usb/siano/smsusb.c @@ -389,7 +389,7 @@ static int smsusb_init_device(struct usb_interface *intf, int board_id) struct smsusb_device_t *dev; void *mdev; int i, rc; - int in_maxp = 0; + int align = 0;

/* create device object */ dev = kzalloc(sizeof(struct smsusb_device_t), GFP_KERNEL); @@ -407,14 +407,14 @@ static int smsusb_init_device(struct usb_interface *intf, int board_id)

if (desc->bEndpointAddress & USB_DIR_IN) { dev->in_ep = desc->bEndpointAddress; - in_maxp = usb_endpoint_maxp(desc); + align = usb_endpoint_maxp(desc) - sizeof(struct sms_msg_hdr); } else { dev->out_ep = desc->bEndpointAddress; } }

pr_debug("in_ep = %02x, out_ep = %02x\n", dev->in_ep, dev->out_ep); - if (!dev->in_ep || !dev->out_ep) { /* Missing endpoints? */ + if (!dev->in_ep || !dev->out_ep || align < 0) { /* Missing endpoints? */ smsusb_term_device(intf); return -ENODEV; } @@ -433,7 +433,7 @@ static int smsusb_init_device(struct usb_interface *intf, int board_id) /* fall-thru */ default: dev->buffer_size = USB2_BUFFER_SIZE; - dev->response_alignment = in_maxp - sizeof(struct sms_msg_hdr); + dev->response_alignment = align;

params.flags |= SMS_DEVICE_FAMILY2; break;