From ee929d5a10ca433a1c21b9aaeb70a67c5507c101 Mon Sep 17 00:00:00 2001 From: Ricardo Ribalda Date: Fri, 18 Jun 2021 14:29:16 +0200 Subject: media: uvcvideo: Check controls flags before accessing them We can figure out if reading/writing a set of controls can fail without accessing them by checking their flags. This way we can honor the API closer: If an error is found when validating the list of controls passed with VIDIOC_G_EXT_CTRLS, then error_idx shall be set to ctrls->count to indicate to userspace that no actual hardware was touched. Fixes v4l2-compliance: Control ioctls (Input 0): warn: v4l2-test-controls.cpp(765): g_ext_ctrls(0) invalid error_idx 0 fail: v4l2-test-controls.cpp(645): invalid error index write only control test VIDIOC_G/S/TRY_EXT_CTRLS: FAIL Reviewed-by: Hans Verkuil Signed-off-by: Ricardo Ribalda Signed-off-by: Laurent Pinchart Signed-off-by: Mauro Carvalho Chehab --- drivers/media/usb/uvc/uvc_ctrl.c | 22 ++++++++++++++++++++++ drivers/media/usb/uvc/uvc_v4l2.c | 39 ++++++++++++++++++++++++++++++++++----- drivers/media/usb/uvc/uvcvideo.h | 2 ++ 3 files changed, 58 insertions(+), 5 deletions(-) (limited to 'drivers') diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c index 2cc2ff0d0cae..18c315b52ef5 100644 --- a/drivers/media/usb/uvc/uvc_ctrl.c +++ b/drivers/media/usb/uvc/uvc_ctrl.c @@ -1042,6 +1042,28 @@ static int uvc_query_v4l2_class(struct uvc_video_chain *chain, u32 req_id, return 0; } +int uvc_ctrl_is_accessible(struct uvc_video_chain *chain, u32 v4l2_id, + bool read) +{ + struct uvc_control_mapping *mapping; + struct uvc_control *ctrl; + + if (__uvc_query_v4l2_class(chain, v4l2_id, 0) >= 0) + return -EACCES; + + ctrl = uvc_find_control(chain, v4l2_id, &mapping); + if (!ctrl) + return -EINVAL; + + if (!(ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR) && read) + return -EACCES; + + if (!(ctrl->info.flags & UVC_CTRL_FLAG_SET_CUR) && !read) + return -EACCES; + + return 0; +} + static const char *uvc_map_get_name(const struct uvc_control_mapping *map) { const char *name; diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c index c6ec7dc920e0..c10a638fff22 100644 --- a/drivers/media/usb/uvc/uvc_v4l2.c +++ b/drivers/media/usb/uvc/uvc_v4l2.c @@ -1003,6 +1003,26 @@ static int uvc_ioctl_query_ext_ctrl(struct file *file, void *fh, return 0; } +static int uvc_ctrl_check_access(struct uvc_video_chain *chain, + struct v4l2_ext_controls *ctrls, + unsigned long ioctl) +{ + struct v4l2_ext_control *ctrl = ctrls->controls; + unsigned int i; + int ret = 0; + + for (i = 0; i < ctrls->count; ++ctrl, ++i) { + ret = uvc_ctrl_is_accessible(chain, ctrl->id, + ioctl == VIDIOC_G_EXT_CTRLS); + if (ret) + break; + } + + ctrls->error_idx = ioctl == VIDIOC_TRY_EXT_CTRLS ? i : ctrls->count; + + return ret; +} + static int uvc_ioctl_g_ext_ctrls(struct file *file, void *fh, struct v4l2_ext_controls *ctrls) { @@ -1012,6 +1032,10 @@ static int uvc_ioctl_g_ext_ctrls(struct file *file, void *fh, unsigned int i; int ret; + ret = uvc_ctrl_check_access(chain, ctrls, VIDIOC_G_EXT_CTRLS); + if (ret < 0) + return ret; + if (ctrls->which == V4L2_CTRL_WHICH_DEF_VAL) { for (i = 0; i < ctrls->count; ++ctrl, ++i) { struct v4l2_queryctrl qc = { .id = ctrl->id }; @@ -1048,13 +1072,17 @@ static int uvc_ioctl_g_ext_ctrls(struct file *file, void *fh, static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle, struct v4l2_ext_controls *ctrls, - bool commit) + unsigned long ioctl) { struct v4l2_ext_control *ctrl = ctrls->controls; struct uvc_video_chain *chain = handle->chain; unsigned int i; int ret; + ret = uvc_ctrl_check_access(chain, ctrls, ioctl); + if (ret < 0) + return ret; + ret = uvc_ctrl_begin(chain); if (ret < 0) return ret; @@ -1063,14 +1091,15 @@ static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle, ret = uvc_ctrl_set(handle, ctrl); if (ret < 0) { uvc_ctrl_rollback(handle); - ctrls->error_idx = commit ? ctrls->count : i; + ctrls->error_idx = ioctl == VIDIOC_S_EXT_CTRLS ? + ctrls->count : i; return ret; } } ctrls->error_idx = 0; - if (commit) + if (ioctl == VIDIOC_S_EXT_CTRLS) return uvc_ctrl_commit(handle, ctrls->controls, ctrls->count); else return uvc_ctrl_rollback(handle); @@ -1081,7 +1110,7 @@ static int uvc_ioctl_s_ext_ctrls(struct file *file, void *fh, { struct uvc_fh *handle = fh; - return uvc_ioctl_s_try_ext_ctrls(handle, ctrls, true); + return uvc_ioctl_s_try_ext_ctrls(handle, ctrls, VIDIOC_S_EXT_CTRLS); } static int uvc_ioctl_try_ext_ctrls(struct file *file, void *fh, @@ -1089,7 +1118,7 @@ static int uvc_ioctl_try_ext_ctrls(struct file *file, void *fh, { struct uvc_fh *handle = fh; - return uvc_ioctl_s_try_ext_ctrls(handle, ctrls, false); + return uvc_ioctl_s_try_ext_ctrls(handle, ctrls, VIDIOC_TRY_EXT_CTRLS); } static int uvc_ioctl_querymenu(struct file *file, void *fh, diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h index b044d9455b2c..4aa78591d9b0 100644 --- a/drivers/media/usb/uvc/uvcvideo.h +++ b/drivers/media/usb/uvc/uvcvideo.h @@ -901,6 +901,8 @@ static inline int uvc_ctrl_rollback(struct uvc_fh *handle) int uvc_ctrl_get(struct uvc_video_chain *chain, struct v4l2_ext_control *xctrl); int uvc_ctrl_set(struct uvc_fh *handle, struct v4l2_ext_control *xctrl); +int uvc_ctrl_is_accessible(struct uvc_video_chain *chain, u32 v4l2_id, + bool read); int uvc_xu_ctrl_query(struct uvc_video_chain *chain, struct uvc_xu_control_query *xqry); -- cgit v1.2.3