From: Jiri Slaby jslaby@suse.cz
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
--- drivers/tty/vt/selection.c | 13 ++++++++++++- drivers/tty/vt/vt.c | 2 -- 2 files changed, 12 insertions(+), 3 deletions(-)
--- a/drivers/tty/vt/selection.c +++ b/drivers/tty/vt/selection.c @@ -157,7 +157,7 @@ static int store_utf8(u16 c, char *p) * 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; @@ -333,6 +333,17 @@ unlock: 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(). --- a/drivers/tty/vt/vt.c +++ b/drivers/tty/vt/vt.c @@ -2688,9 +2688,7 @@ int tioclinux(struct tty_struct *tty, un 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);