V4L/DVB (8773): cx18: Fix cx18_find_handle() and add error checking

cx18: Fix cx18_find_handle() and add error checking.  cx18_find_handle() did
not find a good task handle and would use the invalid task handle under common
conditions.  Added a define for the invalid task handle and added error checking
as well.

Signed-off-by: Andy Walls <awalls@radix.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 15 insertions, 2 deletions

diff --git a/drivers/media/video/cx18/cx18-ioctl.c b/drivers/media/video/cx18/cx18-ioctl.c
index 5325c7aacaf3..84507a39f2b8 100644
--- a/drivers/media/video/cx18/cx18-ioctl.c
+++ b/drivers/media/video/cx18/cx18-ioctl.c
@@ -622,6 +622,7 @@ static int cx18_encoder_cmd(struct file *file, void *fh,
 {
         struct cx18_open_id *id = fh;
         struct cx18 *cx = id->cx;
+        u32 h;
 
         switch (enc->cmd) {
         case V4L2_ENC_CMD_START:
@@ -643,8 +644,14 @@ static int cx18_encoder_cmd(struct file *file, void *fh,
                         return -EPERM;
                 if (test_and_set_bit(CX18_F_I_ENC_PAUSED, &cx->i_flags))
                         return 0;
+                h = cx18_find_handle(cx);
+                if (h == CX18_INVALID_TASK_HANDLE) {
+                        CX18_ERR("Can't find valid task handle for "
+                                 "V4L2_ENC_CMD_PAUSE\n");
+                        return -EBADFD;
+                }
                 cx18_mute(cx);
-                cx18_vapi(cx, CX18_CPU_CAPTURE_PAUSE, 1, cx18_find_handle(cx));
+                cx18_vapi(cx, CX18_CPU_CAPTURE_PAUSE, 1, h);
                 break;
 
         case V4L2_ENC_CMD_RESUME:
@@ -654,7 +661,13 @@ static int cx18_encoder_cmd(struct file *file, void *fh,
                         return -EPERM;
                 if (!test_and_clear_bit(CX18_F_I_ENC_PAUSED, &cx->i_flags))
                         return 0;
-                cx18_vapi(cx, CX18_CPU_CAPTURE_RESUME, 1, cx18_find_handle(cx));
+                h = cx18_find_handle(cx);
+                if (h == CX18_INVALID_TASK_HANDLE) {
+                        CX18_ERR("Can't find valid task handle for "
+                                 "V4L2_ENC_CMD_RESUME\n");
+                        return -EBADFD;
+                }
+                cx18_vapi(cx, CX18_CPU_CAPTURE_RESUME, 1, h);
                 cx18_unmute(cx);
                 break;