queue-4.19/media-smsusb-better-handle-optional-alignment.patch

   1 From a47686636d84eaec5c9c6e84bd5f96bed34d526d Mon Sep 17 00:00:00 2001
   2 From: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
   3 Date: Fri, 24 May 2019 10:59:43 -0400
   4 Subject: media: smsusb: better handle optional alignment
   5
   6 From: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
   7
   8 commit a47686636d84eaec5c9c6e84bd5f96bed34d526d upstream.
   9
  10 Most Siano devices require an alignment for the response.
  11
  12 Changeset f3be52b0056a ("media: usb: siano: Fix general protection fault in smsusb")
  13 changed the logic with gets such aligment, but it now produces a
  14 sparce warning:
  15
  16 drivers/media/usb/siano/smsusb.c: In function 'smsusb_init_device':
  17 drivers/media/usb/siano/smsusb.c:447:37: warning: 'in_maxp' may be used uninitialized in this function [-Wmaybe-uninitialized]
  18   447 |   dev->response_alignment = in_maxp - sizeof(struct sms_msg_hdr);
  19       |                             ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
  20
  21 The sparse message itself is bogus, but a broken (or fake) USB
  22 eeprom could produce a negative value for response_alignment.
  23
  24 So, change the code in order to check if the result is not
  25 negative.
  26
  27 Fixes: 31e0456de5be ("media: usb: siano: Fix general protection fault in smsusb")
  28 CC: <stable@vger.kernel.org>
  29 Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
  30 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  31
  32 ---
  33  drivers/media/usb/siano/smsusb.c |    8 ++++----
  34  1 file changed, 4 insertions(+), 4 deletions(-)
  35
  36 --- a/drivers/media/usb/siano/smsusb.c
  37 +++ b/drivers/media/usb/siano/smsusb.c
  38 @@ -401,7 +401,7 @@ static int smsusb_init_device(struct usb
  39         struct smsusb_device_t *dev;
  40         void *mdev;
  41         int i, rc;
  42 -       int in_maxp = 0;
  43 +       int align = 0;
  44
  45         /* create device object */
  46         dev = kzalloc(sizeof(struct smsusb_device_t), GFP_KERNEL);
  47 @@ -419,14 +419,14 @@ static int smsusb_init_device(struct usb
  48
  49                 if (desc->bEndpointAddress & USB_DIR_IN) {
  50                         dev->in_ep = desc->bEndpointAddress;
  51 -                       in_maxp = usb_endpoint_maxp(desc);
  52 +                       align = usb_endpoint_maxp(desc) - sizeof(struct sms_msg_hdr);
  53                 } else {
  54                         dev->out_ep = desc->bEndpointAddress;
  55                 }
  56         }
  57
  58         pr_debug("in_ep = %02x, out_ep = %02x\n", dev->in_ep, dev->out_ep);
  59 -       if (!dev->in_ep || !dev->out_ep) {      /* Missing endpoints? */
  60 +       if (!dev->in_ep || !dev->out_ep || align < 0) {  /* Missing endpoints? */
  61                 smsusb_term_device(intf);
  62                 return -ENODEV;
  63         }
  64 @@ -445,7 +445,7 @@ static int smsusb_init_device(struct usb
  65                 /* fall-thru */
  66         default:
  67                 dev->buffer_size = USB2_BUFFER_SIZE;
  68 -               dev->response_alignment = in_maxp - sizeof(struct sms_msg_hdr);
  69 +               dev->response_alignment = align;
  70
  71                 params.flags |= SMS_DEVICE_FAMILY2;
  72                 break;