From f0da34f32920c16f34acb692cf1646465bd40c04 Mon Sep 17 00:00:00 2001 From: Hans Verkuil Date: Wed, 18 May 2022 14:06:31 +0100 Subject: 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: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- drivers/media/v4l2-core/v4l2-ioctl.c | 26 ++++++++++++-------------- 1 file changed, 12 insertions(+), 14 deletions(-) (limited to 'drivers/media') diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c index c314025d977e..e6fd355a2e92 100644 --- a/drivers/media/v4l2-core/v4l2-ioctl.c +++ b/drivers/media/v4l2-core/v4l2-ioctl.c @@ -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: -- cgit v1.2.3-59-g8ed1b