From: Minseong Kim Date: Fri, 12 Dec 2025 08:29:23 +0000 (-0800) Subject: Input: lkkbd - disable pending work before freeing device X-Git-Tag: v6.19-rc2~2^2~7 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e58c88f0cb2d8ed89de78f6f17409d29cfab6c5c;p=thirdparty%2Flinux.git Input: lkkbd - disable pending work before freeing device lkkbd_interrupt() schedules lk->tq via schedule_work(), and the work handler lkkbd_reinit() dereferences the lkkbd structure and its serio/input_dev fields. lkkbd_disconnect() and error paths in lkkbd_connect() free the lkkbd structure without preventing the reinit work from being queued again until serio_close() returns. This can allow the work handler to run after the structure has been freed, leading to a potential use-after-free. Use disable_work_sync() instead of cancel_work_sync() to ensure the reinit work cannot be re-queued, and call it both in lkkbd_disconnect() and in lkkbd_connect() error paths after serio_open(). Signed-off-by: Minseong Kim Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20251212052314.16139-1-ii4gsp@gmail.com Signed-off-by: Dmitry Torokhov --- diff --git a/drivers/input/keyboard/lkkbd.c b/drivers/input/keyboard/lkkbd.c index c035216dd27c1..2f130f819363c 100644 --- a/drivers/input/keyboard/lkkbd.c +++ b/drivers/input/keyboard/lkkbd.c @@ -670,7 +670,8 @@ static int lkkbd_connect(struct serio *serio, struct serio_driver *drv) return 0; - fail3: serio_close(serio); + fail3: disable_work_sync(&lk->tq); + serio_close(serio); fail2: serio_set_drvdata(serio, NULL); fail1: input_free_device(input_dev); kfree(lk); @@ -684,6 +685,8 @@ static void lkkbd_disconnect(struct serio *serio) { struct lkkbd *lk = serio_get_drvdata(serio); + disable_work_sync(&lk->tq); + input_get_device(lk->dev); input_unregister_device(lk->dev); serio_close(serio);