On (09/03/18 17:52), Dmitry Safonov wrote:
We've seen the following crash on v4.9.108 stable:
BUG: unable to handle kernel paging request at 0000000000002260 IP: [..] n_tty_receive_buf_common+0x5f/0x86d Workqueue: events_unbound flush_to_ldisc Call Trace: [..] n_tty_receive_buf2 [..] tty_ldisc_receive_buf [..] flush_to_ldisc [..] process_one_work [..] worker_thread [..] kthread [..] ret_from_fork
tty_ldisc_reinit() should be called with ldisc_sem hold for writing, which will protect any reader against line discipline changes.
Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: Jiri Slaby jslaby@suse.com Cc: stable@vger.kernel.org # depends on commit b027e2298bd5 ("tty: fix data race between tty_init_dev and flush of buf")
I believe there's a "Fixes" tag for that
Fixes: b027e2298bd5 ("tty: fix data race between tty_init_dev and flush of buf") Cc: stable@vger.kernel.org
-ss