Commit efbceecd4522a41b8442c6b4f68b4508d57d1ccf, adds a number of helper functions for ctrl related ioctls to v4l2-ioctl.c, these helpers assume that if file->private_data != NULL, it points to a v4l2_fh, which is only the case for drivers which actually use v4l2_fh. This breaks for example bttv which use the "filedata" pointer for its own uses, and now all the ctrl ioctls try to use whatever its filedata points to as v4l2_fh and think it has a ctrl_handler, leading to: [ 142.499214] BUG: unable to handle kernel NULL pointer dereference at 0000000000000021 [ 142.499270] IP: [<ffffffffa01cb959>] v4l2_queryctrl+0x29/0x230 [videodev] [ 142.514649] [<ffffffffa01c7a77>] v4l_queryctrl+0x47/0x90 [videodev] [ 142.517417] [<ffffffffa01c58b1>] __video_do_ioctl+0x2c1/0x420 [videodev] [ 142.520116] [<ffffffffa01c7ee6>] video_usercopy+0x1a6/0x470 [videodev] ... This patch adds the missing test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags) tests to the ctrl ioctl helpers v4l2_fh paths, fixing the issues with for example the bttv driver. Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> --- drivers/media/video/v4l2-ioctl.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) diff --git a/drivers/media/video/v4l2-ioctl.c b/drivers/media/video/v4l2-ioctl.c index 70e0efb..3c498b2 100644 --- a/drivers/media/video/v4l2-ioctl.c +++ b/drivers/media/video/v4l2-ioctl.c @@ -1488,7 +1488,8 @@ static int v4l_queryctrl(const struct v4l2_ioctl_ops *ops, struct v4l2_queryctrl *p = arg; struct v4l2_fh *vfh = fh; - if (vfh && vfh->ctrl_handler) + if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags) && + vfh && vfh->ctrl_handler) return v4l2_queryctrl(vfh->ctrl_handler, p); if (vfd->ctrl_handler) return v4l2_queryctrl(vfd->ctrl_handler, p); @@ -1504,7 +1505,8 @@ static int v4l_querymenu(const struct v4l2_ioctl_ops *ops, struct v4l2_querymenu *p = arg; struct v4l2_fh *vfh = fh; - if (vfh && vfh->ctrl_handler) + if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags) && + vfh && vfh->ctrl_handler) return v4l2_querymenu(vfh->ctrl_handler, p); if (vfd->ctrl_handler) return v4l2_querymenu(vfd->ctrl_handler, p); @@ -1522,7 +1524,8 @@ static int v4l_g_ctrl(const struct v4l2_ioctl_ops *ops, struct v4l2_ext_controls ctrls; struct v4l2_ext_control ctrl; - if (vfh && vfh->ctrl_handler) + if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags) && + vfh && vfh->ctrl_handler) return v4l2_g_ctrl(vfh->ctrl_handler, p); if (vfd->ctrl_handler) return v4l2_g_ctrl(vfd->ctrl_handler, p); @@ -1555,7 +1558,8 @@ static int v4l_s_ctrl(const struct v4l2_ioctl_ops *ops, struct v4l2_ext_controls ctrls; struct v4l2_ext_control ctrl; - if (vfh && vfh->ctrl_handler) + if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags) && + vfh && vfh->ctrl_handler) return v4l2_s_ctrl(vfh, vfh->ctrl_handler, p); if (vfd->ctrl_handler) return v4l2_s_ctrl(NULL, vfd->ctrl_handler, p); @@ -1582,7 +1586,8 @@ static int v4l_g_ext_ctrls(const struct v4l2_ioctl_ops *ops, struct v4l2_fh *vfh = fh; p->error_idx = p->count; - if (vfh && vfh->ctrl_handler) + if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags) && + vfh && vfh->ctrl_handler) return v4l2_g_ext_ctrls(vfh->ctrl_handler, p); if (vfd->ctrl_handler) return v4l2_g_ext_ctrls(vfd->ctrl_handler, p); @@ -1600,7 +1605,8 @@ static int v4l_s_ext_ctrls(const struct v4l2_ioctl_ops *ops, struct v4l2_fh *vfh = fh; p->error_idx = p->count; - if (vfh && vfh->ctrl_handler) + if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags) && + vfh && vfh->ctrl_handler) return v4l2_s_ext_ctrls(vfh, vfh->ctrl_handler, p); if (vfd->ctrl_handler) return v4l2_s_ext_ctrls(NULL, vfd->ctrl_handler, p); @@ -1618,7 +1624,8 @@ static int v4l_try_ext_ctrls(const struct v4l2_ioctl_ops *ops, struct v4l2_fh *vfh = fh; p->error_idx = p->count; - if (vfh && vfh->ctrl_handler) + if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags) && + vfh && vfh->ctrl_handler) return v4l2_try_ext_ctrls(vfh->ctrl_handler, p); if (vfd->ctrl_handler) return v4l2_try_ext_ctrls(vfd->ctrl_handler, p); -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
