| Message ID | f7cff5c05f950ab28532f71d5ac7a4a8efed38fb.1729074076.git.mchehab+huawei@kernel.org |
|---|---|
| State | New |
| Headers | show |
| Series | Media: fix several issues on drivers | expand |
On 16/10/2024 12:22, Mauro Carvalho Chehab wrote: > The error check logic at get_ctrl() is broken: if ptr_to_user() > fails to fill a control due to an error, no errors are returned > and v4l2_g_ctrl() returns success on a failed operation, which > may cause applications to fail. > > Add an error check at get_ctrl() and ensure that it will > be returned to userspace without filling the control value if > get_ctrl() fails. > > Fixes: 71c689dc2e73 ("media: v4l2-ctrls: split up into four source files") > Cc: stable@vger.kernel.org > Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> > --- > drivers/media/v4l2-core/v4l2-ctrls-api.c | 10 +++++++--- > 1 file changed, 7 insertions(+), 3 deletions(-) > > diff --git a/drivers/media/v4l2-core/v4l2-ctrls-api.c b/drivers/media/v4l2-core/v4l2-ctrls-api.c > index e5a364efd5e6..be32dccf9830 100644 > --- a/drivers/media/v4l2-core/v4l2-ctrls-api.c > +++ b/drivers/media/v4l2-core/v4l2-ctrls-api.c > @@ -753,9 +753,10 @@ static int get_ctrl(struct v4l2_ctrl *ctrl, struct v4l2_ext_control *c) > for (i = 0; i < master->ncontrols; i++) > cur_to_new(master->cluster[i]); > ret = call_op(master, g_volatile_ctrl); > - new_to_user(c, ctrl); > + if (!ret) > + ret = new_to_user(c, ctrl); > } else { > - cur_to_user(c, ctrl); > + ret = cur_to_user(c, ctrl); > } > v4l2_ctrl_unlock(master); > return ret; > @@ -770,7 +771,10 @@ int v4l2_g_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_control *control) > if (!ctrl || !ctrl->is_int) > return -EINVAL; > ret = get_ctrl(ctrl, &c); > - control->value = c.value; > + > + if (!ret) > + control->value = c.value; > + > return ret; > } > EXPORT_SYMBOL(v4l2_g_ctrl); Yeah, that's better. There are also unchecked calls to cur_to_user() and user_to_new() in set_ctrl_lock(). Can you fix that as well? Regards, Hans
diff --git a/drivers/media/v4l2-core/v4l2-ctrls-api.c b/drivers/media/v4l2-core/v4l2-ctrls-api.c index e5a364efd5e6..be32dccf9830 100644 --- a/drivers/media/v4l2-core/v4l2-ctrls-api.c +++ b/drivers/media/v4l2-core/v4l2-ctrls-api.c @@ -753,9 +753,10 @@ static int get_ctrl(struct v4l2_ctrl *ctrl, struct v4l2_ext_control *c) for (i = 0; i < master->ncontrols; i++) cur_to_new(master->cluster[i]); ret = call_op(master, g_volatile_ctrl); - new_to_user(c, ctrl); + if (!ret) + ret = new_to_user(c, ctrl); } else { - cur_to_user(c, ctrl); + ret = cur_to_user(c, ctrl); } v4l2_ctrl_unlock(master); return ret; @@ -770,7 +771,10 @@ int v4l2_g_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_control *control) if (!ctrl || !ctrl->is_int) return -EINVAL; ret = get_ctrl(ctrl, &c); - control->value = c.value; + + if (!ret) + control->value = c.value; + return ret; } EXPORT_SYMBOL(v4l2_g_ctrl);
The error check logic at get_ctrl() is broken: if ptr_to_user() fails to fill a control due to an error, no errors are returned and v4l2_g_ctrl() returns success on a failed operation, which may cause applications to fail. Add an error check at get_ctrl() and ensure that it will be returned to userspace without filling the control value if get_ctrl() fails. Fixes: 71c689dc2e73 ("media: v4l2-ctrls: split up into four source files") Cc: stable@vger.kernel.org Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> --- drivers/media/v4l2-core/v4l2-ctrls-api.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)