diff options
| author | Sean Young <sean@mess.org> | 2017-08-04 10:12:03 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-09-27 14:43:20 +0200 |
| commit | e2204d254f27087a71e58d371b2a60bddf3e7c54 (patch) | |
| tree | c4385bc0685a4714aa8afebba80463b2eafc99d6 /drivers | |
| parent | a0416c1e96556d59de02b672b574994572a38444 (diff) | |
media: Revert "[media] lirc_dev: remove superfluous get/put_device() calls"
commit a607f51e5a4c421e2097077db88105402099c528 upstream.
This reverts commit 5be2b76a9ca4ea5fd3e221114d62eeb0d78267ca.
Only when the lirc device is freed, should we drop our reference to
rc_dev, else we the rc_dev is freed to early. If userspace has
a file descriptor open during unplug, it goes bang.
==================================================================
BUG: KASAN: use-after-free in __lock_acquire+0x7bb/0x1e10
Read of size 8 at addr ffff8801d7d61ed0 by task ir-rec/2609
-snip-
mutex_lock_nested+0x1b/0x20
? mutex_lock_nested+0x1b/0x20
rc_close.part.6+0x20/0x60 [rc_core]
rc_close+0x13/0x20 [rc_core]
lirc_dev_fop_close+0x62/0xd0 [lirc_dev]
__fput+0x236/0x410
? fput+0xb0/0xb0
? do_raw_spin_trylock+0x110/0x110
? set_rq_offline.part.70+0xa0/0xa0
____fput+0xe/0x10
task_work_run+0x116/0x180
? task_work_cancel+0x170/0x170
? _raw_spin_unlock+0x27/0x40
? switch_task_namespaces+0x5f/0x90
do_exit+0x68b/0xe80
Fixes: 5be2b76a9ca4 ("[media] lirc_dev: remove superfluous get/put_device() calls")
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/media/rc/lirc_dev.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/media/rc/lirc_dev.c b/drivers/media/rc/lirc_dev.c index db1e7b70c998..9080e39ea391 100644 --- a/drivers/media/rc/lirc_dev.c +++ b/drivers/media/rc/lirc_dev.c @@ -59,6 +59,8 @@ static void lirc_release(struct device *ld) { struct irctl *ir = container_of(ld, struct irctl, dev); + put_device(ir->dev.parent); + if (ir->buf_internal) { lirc_buffer_free(ir->buf); kfree(ir->buf); @@ -218,6 +220,8 @@ int lirc_register_driver(struct lirc_driver *d) mutex_unlock(&lirc_dev_lock); + get_device(ir->dev.parent); + dev_info(ir->d.dev, "lirc_dev: driver %s registered at minor = %d\n", ir->d.name, ir->d.minor); |