mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-05-06 04:19:23 -04:00
a607f51e5a
This reverts commit5be2b76a9c. 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 Cc: stable@vger.kernel.org # For Kernel 4.13 Fixes:5be2b76a9c("[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>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.