From 115bbf64fb5f098ef7a2342c8fdd82d3f9230931 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Tue, 15 Oct 2024 14:23:38 +0200 Subject: [PATCH] media: v4l2-ctrls-api: fix error handling for v4l2_g_ctrl() 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 Signed-off-by: Greg Kroah-Hartman --- drivers/media/v4l2-core/v4l2-ctrls-api.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/drivers/media/v4l2-core/v4l2-ctrls-api.c b/drivers/media/v4l2-core/v4l2-ctrls-api.c index 002ea6588edf1..64b0c3ef27f5e 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 +815,11 @@ 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 = 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; }