6.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: Mauro Carvalho Chehab mchehab+huawei@kernel.org
commit 4c76f331a9a173ac8fe1297a9231c2a38f88e368 upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/media/v4l2-core/v4l2-ctrls-api.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-)
--- 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 *ct 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 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 +815,11 @@ static int set_ctrl_lock(struct v4l2_fh int ret;
v4l2_ctrl_lock(ctrl); - user_to_new(c, ctrl); - ret = set_ctrl(fh, ctrl, 0); + ret = user_to_new(c, ctrl); + if (!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; }