vt: selection, push console lock down
commit 4b70dd57a15d2f4685ac6e38056bad93e81e982f upstream.
We need to nest the console lock in sel_lock, so we have to push it down
a bit. Fortunately, the callers of set_selection_* just lock the console
lock around the function call. So moving it down is easy.
In the next patch, we switch the order.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Fixes: 07e6124a1a46 ("vt: selection, close sel_buffer race")
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200228115406.5735-1-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Change-Id: Id2c59634d86490a5771bfbe7d724a4b2f7544c4d
diff --git a/drivers/tty/vt/selection.c b/drivers/tty/vt/selection.c
index df0f610..cb0f79c 100644
--- a/drivers/tty/vt/selection.c
+++ b/drivers/tty/vt/selection.c
@@ -158,7 +158,7 @@
* The entire selection process is managed under the console_lock. It's
* a lot under the lock but its hardly a performance path
*/
-int set_selection(const struct tiocl_selection __user *sel, struct tty_struct *tty)
+static int __set_selection(const struct tiocl_selection __user *sel, struct tty_struct *tty)
{
struct vc_data *vc = vc_cons[fg_console].d;
int sel_mode, new_sel_start, new_sel_end, spc;
@@ -334,6 +334,17 @@
return ret;
}
+int set_selection(const struct tiocl_selection __user *v, struct tty_struct *tty)
+{
+ int ret;
+
+ console_lock();
+ ret = __set_selection(v, tty);
+ console_unlock();
+
+ return ret;
+}
+
/* Insert the contents of the selection buffer into the
* queue of the tty associated with the current console.
* Invoked by ioctl().
diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index 322c481..60d0d6a 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -2661,9 +2661,7 @@
switch (type)
{
case TIOCL_SETSEL:
- console_lock();
ret = set_selection((struct tiocl_selection __user *)(p+1), tty);
- console_unlock();
break;
case TIOCL_PASTESEL:
ret = paste_selection(tty);
