This is a note to let you know that I've just added the patch titled
iio: trigger: sysfs: fix use-after-free on remove
to my char-misc git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git in the char-misc-linus branch.
The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.
If you have any questions about this process, please let me know.
From 78601726d4a59a291acc5a52da1d3a0a6831e4e8 Mon Sep 17 00:00:00 2001 From: Vincent Whitchurch vincent.whitchurch@axis.com Date: Thu, 19 May 2022 11:19:25 +0200 Subject: iio: trigger: sysfs: fix use-after-free on remove
Ensure that the irq_work has completed before the trigger is freed.
================================================================== BUG: KASAN: use-after-free in irq_work_run_list Read of size 8 at addr 0000000064702248 by task python3/25
Call Trace: irq_work_run_list irq_work_tick update_process_times tick_sched_handle tick_sched_timer __hrtimer_run_queues hrtimer_interrupt
Allocated by task 25: kmem_cache_alloc_trace iio_sysfs_trig_add dev_attr_store sysfs_kf_write kernfs_fop_write_iter new_sync_write vfs_write ksys_write sys_write
Freed by task 25: kfree iio_sysfs_trig_remove dev_attr_store sysfs_kf_write kernfs_fop_write_iter new_sync_write vfs_write ksys_write sys_write
==================================================================
Fixes: f38bc926d022 ("staging:iio:sysfs-trigger: Use irq_work to properly active trigger") Signed-off-by: Vincent Whitchurch vincent.whitchurch@axis.com Reviewed-by: Lars-Peter Clausen lars@metafoo.de Link: https://lore.kernel.org/r/20220519091925.1053897-1-vincent.whitchurch@axis.c... Cc: Stable@vger.kernel.org Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com --- drivers/iio/trigger/iio-trig-sysfs.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/drivers/iio/trigger/iio-trig-sysfs.c b/drivers/iio/trigger/iio-trig-sysfs.c index 2a4b75897910..3d911c24b265 100644 --- a/drivers/iio/trigger/iio-trig-sysfs.c +++ b/drivers/iio/trigger/iio-trig-sysfs.c @@ -191,6 +191,7 @@ static int iio_sysfs_trigger_remove(int id) }
iio_trigger_unregister(t->trig); + irq_work_sync(&t->work); iio_trigger_free(t->trig);
list_del(&t->l);