This is a note to let you know that I've just added the patch titled Input: sunkbd - avoid use-after-free in teardown paths to the 4.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: input-sunkbd-avoid-use-after-free-in-teardown-paths.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 77e70d351db7de07a46ac49b87a6c3c7a60fca7e Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> Date: Mon, 26 Oct 2020 13:36:17 -0700 Subject: Input: sunkbd - avoid use-after-free in teardown paths From: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> commit 77e70d351db7de07a46ac49b87a6c3c7a60fca7e upstream. We need to make sure we cancel the reinit work before we tear down the driver structures. Reported-by: Bodong Zhao <nopitydays@xxxxxxxxx> Tested-by: Bodong Zhao <nopitydays@xxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/input/keyboard/sunkbd.c | 41 ++++++++++++++++++++++++++++++++-------- 1 file changed, 33 insertions(+), 8 deletions(-) --- a/drivers/input/keyboard/sunkbd.c +++ b/drivers/input/keyboard/sunkbd.c @@ -111,7 +111,8 @@ static irqreturn_t sunkbd_interrupt(stru switch (data) { case SUNKBD_RET_RESET: - schedule_work(&sunkbd->tq); + if (sunkbd->enabled) + schedule_work(&sunkbd->tq); sunkbd->reset = -1; break; @@ -212,16 +213,12 @@ static int sunkbd_initialize(struct sunk } /* - * sunkbd_reinit() sets leds and beeps to a state the computer remembers they - * were in. + * sunkbd_set_leds_beeps() sets leds and beeps to a state the computer remembers + * they were in. */ -static void sunkbd_reinit(struct work_struct *work) +static void sunkbd_set_leds_beeps(struct sunkbd *sunkbd) { - struct sunkbd *sunkbd = container_of(work, struct sunkbd, tq); - - wait_event_interruptible_timeout(sunkbd->wait, sunkbd->reset >= 0, HZ); - serio_write(sunkbd->serio, SUNKBD_CMD_SETLED); serio_write(sunkbd->serio, (!!test_bit(LED_CAPSL, sunkbd->dev->led) << 3) | @@ -234,11 +231,39 @@ static void sunkbd_reinit(struct work_st SUNKBD_CMD_BELLOFF - !!test_bit(SND_BELL, sunkbd->dev->snd)); } + +/* + * sunkbd_reinit() wait for the keyboard reset to complete and restores state + * of leds and beeps. + */ + +static void sunkbd_reinit(struct work_struct *work) +{ + struct sunkbd *sunkbd = container_of(work, struct sunkbd, tq); + + /* + * It is OK that we check sunkbd->enabled without pausing serio, + * as we only want to catch true->false transition that will + * happen once and we will be woken up for it. + */ + wait_event_interruptible_timeout(sunkbd->wait, + sunkbd->reset >= 0 || !sunkbd->enabled, + HZ); + + if (sunkbd->reset >= 0 && sunkbd->enabled) + sunkbd_set_leds_beeps(sunkbd); +} + static void sunkbd_enable(struct sunkbd *sunkbd, bool enable) { serio_pause_rx(sunkbd->serio); sunkbd->enabled = enable; serio_continue_rx(sunkbd->serio); + + if (!enable) { + wake_up_interruptible(&sunkbd->wait); + cancel_work_sync(&sunkbd->tq); + } } /* Patches currently in stable-queue which might be from dmitry.torokhov@xxxxxxxxx are queue-4.19/input-sunkbd-avoid-use-after-free-in-teardown-paths.patch