Commit f0da34f3 authored by Hans Verkuil's avatar Hans Verkuil Committed by Mauro Carvalho Chehab
Browse files

media: v4l2-ioctl.c: fix incorrect error path 



If allocating array_buf fails, or copying data from userspace into that
buffer fails, then just free memory and return the error. Don't attempt
to call video_put_user() since there is no point, and it would copy back
data on error even if INFO_FL_ALWAYS_COPY wasn't set.

So if writing the array back to userspace fails, then don't go to
out_array_args, instead just continue with the regular code that just
returns the error unless 'always_copy' is set.

Update the VIDIOC_G/S/TRY_EXT_CTRLS ioctls to set the ALWAYS_COPY flag
since they now need it. Before this worked due to this buggy code, but
now that that is fixed these ioctls need to set this flag explicitly.

Signed-off-by: default avatarHans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@kernel.org>
parent 4e768c8e

drivers/media/v4l2-core/v4l2-ioctl.c

+12 −14
Original line number Diff line number Diff line
@@ -2872,9 +2872,9 @@ static const struct v4l2_ioctl_info v4l2_ioctls[] = { 
	IOCTL_INFO(VIDIOC_S_PRIORITY, v4l_s_priority, v4l_print_u32, INFO_FL_PRIO),

	IOCTL_INFO(VIDIOC_G_SLICED_VBI_CAP, v4l_g_sliced_vbi_cap, v4l_print_sliced_vbi_cap, INFO_FL_CLEAR(v4l2_sliced_vbi_cap, type)),

	IOCTL_INFO(VIDIOC_LOG_STATUS, v4l_log_status, v4l_print_newline, 0),

	IOCTL_INFO(VIDIOC_G_EXT_CTRLS, v4l_g_ext_ctrls, v4l_print_ext_controls, INFO_FL_CTRL),

	IOCTL_INFO(VIDIOC_S_EXT_CTRLS, v4l_s_ext_ctrls, v4l_print_ext_controls, INFO_FL_PRIO | INFO_FL_CTRL),

	IOCTL_INFO(VIDIOC_TRY_EXT_CTRLS, v4l_try_ext_ctrls, v4l_print_ext_controls, INFO_FL_CTRL),

	IOCTL_INFO(VIDIOC_G_EXT_CTRLS, v4l_g_ext_ctrls, v4l_print_ext_controls, INFO_FL_CTRL | INFO_FL_ALWAYS_COPY),

	IOCTL_INFO(VIDIOC_S_EXT_CTRLS, v4l_s_ext_ctrls, v4l_print_ext_controls, INFO_FL_PRIO | INFO_FL_CTRL | INFO_FL_ALWAYS_COPY),

	IOCTL_INFO(VIDIOC_TRY_EXT_CTRLS, v4l_try_ext_ctrls, v4l_print_ext_controls, INFO_FL_CTRL | INFO_FL_ALWAYS_COPY),

	IOCTL_INFO(VIDIOC_ENUM_FRAMESIZES, v4l_stub_enum_framesizes, v4l_print_frmsizeenum, INFO_FL_CLEAR(v4l2_frmsizeenum, pixel_format)),

	IOCTL_INFO(VIDIOC_ENUM_FRAMEINTERVALS, v4l_stub_enum_frameintervals, v4l_print_frmivalenum, INFO_FL_CLEAR(v4l2_frmivalenum, height)),

	IOCTL_INFO(VIDIOC_G_ENC_INDEX, v4l_stub_g_enc_index, v4l_print_enc_idx, 0),
@@ -3367,8 +3367,7 @@ video_usercopy(struct file *file, unsigned int orig_cmd, unsigned long arg, 
		array_buf = kvmalloc(array_size, GFP_KERNEL);

		err = -ENOMEM;

		if (array_buf == NULL)

			goto out_array_args;

		err = -EFAULT;

			goto out;

		if (in_compat_syscall())

			err = v4l2_compat_get_array_args(file, array_buf,

							 user_ptr, array_size,
@@ -3377,7 +3376,7 @@ video_usercopy(struct file *file, unsigned int orig_cmd, unsigned long arg, 
			err = copy_from_user(array_buf, user_ptr, array_size) ?

								-EFAULT : 0;

		if (err)

			goto out_array_args;

			goto out;

		*kernel_ptr = array_buf;

	}
@@ -3395,6 +3394,13 @@ video_usercopy(struct file *file, unsigned int orig_cmd, unsigned long arg, 
			trace_v4l2_qbuf(video_devdata(file)->minor, parg);

	}



	/*

	 * Some ioctls can return an error, but still have valid

	 * results that must be returned.

	 */

	if (err < 0 && !always_copy)

		goto out;



	if (has_array_args) {

		*kernel_ptr = (void __force *)user_ptr;

		if (in_compat_syscall()) {
@@ -3409,16 +3415,8 @@ video_usercopy(struct file *file, unsigned int orig_cmd, unsigned long arg, 
		} else if (copy_to_user(user_ptr, array_buf, array_size)) {

			err = -EFAULT;

		}

		goto out_array_args;

	}

	/*

	 * Some ioctls can return an error, but still have valid

	 * results that must be returned.

	 */

	if (err < 0 && !always_copy)

		goto out;



out_array_args:

	if (video_put_user((void __user *)arg, parg, cmd, orig_cmd))

		err = -EFAULT;

out: