| Message ID | 4d36ccf66f48a870c9bc0f7e9fda595505c4d342.1729230718.git.mchehab+huawei@kernel.org |
|---|---|
| State | New |
| Headers | show |
| Series | Media: fix several issues on drivers | expand |
On 18/10/2024 07:53, Mauro Carvalho Chehab wrote: > As detected by Coverity, 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 | 16 +++++++++++----- > 1 file changed, 11 insertions(+), 5 deletions(-) > > diff --git a/drivers/media/v4l2-core/v4l2-ctrls-api.c b/drivers/media/v4l2-core/v4l2-ctrls-api.c > index e5a364efd5e6..a0de7eeaf085 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); > @@ -811,10 +815,12 @@ static int set_ctrl_lock(struct v4l2_fh *fh, struct v4l2_ctrl *ctrl, > int ret; > > v4l2_ctrl_lock(ctrl); > - user_to_new(c, ctrl); > + ret = user_to_new(c, ctrl); > + if (ret) > + return ret; A lock was taken above and that isn't unlocked here. It is better to write this as: if (!ret) ret = set_ctrl(fh, ctrl, 0); > ret = set_ctrl(fh, ctrl, 0); > if (!ret) > - cur_to_user(c, ctrl); > + ret = cur_to_user(c, ctrl); > v4l2_ctrl_unlock(ctrl); > return ret; > } Regards, Hans
Hi Mauro,
kernel test robot noticed the following build warnings:
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Mauro-Carvalho-Chehab/media-v4l2-ctrls-api-fix-error-handling-for-v4l2_g_ctrl/20241018-181159
base: https://git.linuxtv.org/media_stage.git master
patch link: https://lore.kernel.org/r/4d36ccf66f48a870c9bc0f7e9fda595505c4d342.1729230718.git.mchehab%2Bhuawei%40kernel.org
patch subject: [PATCH v2 01/13] media: v4l2-ctrls-api: fix error handling for v4l2_g_ctrl()
config: i386-randconfig-141-20241021 (https://download.01.org/0day-ci/archive/20241022/202410220105.oP6D4QD7-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
| Closes: https://lore.kernel.org/r/202410220105.oP6D4QD7-lkp@intel.com/
smatch warnings:
drivers/media/v4l2-core/v4l2-ctrls-api.c:825 set_ctrl_lock() warn: inconsistent returns 'ctrl->handler->lock'.
vim +825 drivers/media/v4l2-core/v4l2-ctrls-api.c
71c689dc2e732d4 Hans Verkuil 2021-04-27 812 static int set_ctrl_lock(struct v4l2_fh *fh, struct v4l2_ctrl *ctrl,
71c689dc2e732d4 Hans Verkuil 2021-04-27 813 struct v4l2_ext_control *c)
71c689dc2e732d4 Hans Verkuil 2021-04-27 814 {
71c689dc2e732d4 Hans Verkuil 2021-04-27 815 int ret;
71c689dc2e732d4 Hans Verkuil 2021-04-27 816
71c689dc2e732d4 Hans Verkuil 2021-04-27 817 v4l2_ctrl_lock(ctrl);
54c5e2c49a4358b Mauro Carvalho Chehab 2024-10-18 818 ret = user_to_new(c, ctrl);
54c5e2c49a4358b Mauro Carvalho Chehab 2024-10-18 819 if (ret)
54c5e2c49a4358b Mauro Carvalho Chehab 2024-10-18 820 return ret;
v4l2_ctrl_unlock() before returning
71c689dc2e732d4 Hans Verkuil 2021-04-27 821 ret = set_ctrl(fh, ctrl, 0);
71c689dc2e732d4 Hans Verkuil 2021-04-27 822 if (!ret)
54c5e2c49a4358b Mauro Carvalho Chehab 2024-10-18 823 ret = cur_to_user(c, ctrl);
71c689dc2e732d4 Hans Verkuil 2021-04-27 824 v4l2_ctrl_unlock(ctrl);
71c689dc2e732d4 Hans Verkuil 2021-04-27 @825 return ret;
71c689dc2e732d4 Hans Verkuil 2021-04-27 826 }
diff --git a/drivers/media/v4l2-core/v4l2-ctrls-api.c b/drivers/media/v4l2-core/v4l2-ctrls-api.c index e5a364efd5e6..a0de7eeaf085 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); @@ -811,10 +815,12 @@ static int set_ctrl_lock(struct v4l2_fh *fh, struct v4l2_ctrl *ctrl, int ret; v4l2_ctrl_lock(ctrl); - user_to_new(c, ctrl); + ret = user_to_new(c, ctrl); + if (ret) + return ret; ret = set_ctrl(fh, ctrl, 0); if (!ret) - cur_to_user(c, ctrl); + ret = cur_to_user(c, ctrl); v4l2_ctrl_unlock(ctrl); return ret; }
As detected by Coverity, 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 | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-)