From: Mauro Carvalho Chehab mchehab+samsung@kernel.org
commit a47686636d84eaec5c9c6e84bd5f96bed34d526d upstream.
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: 31e0456de5be ("media: usb: siano: Fix general protection fault in smsusb") CC: stable@vger.kernel.org Signed-off-by: Mauro Carvalho Chehab mchehab+samsung@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/media/usb/siano/smsusb.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
--- a/drivers/media/usb/siano/smsusb.c +++ b/drivers/media/usb/siano/smsusb.c @@ -402,7 +402,7 @@ static int smsusb_init_device(struct usb 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); @@ -420,14 +420,14 @@ static int smsusb_init_device(struct usb
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; } @@ -446,7 +446,7 @@ static int smsusb_init_device(struct usb /* 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;