Messages in this thread Patch in this message | | | From | Matthias Reichl <> | Subject | [PATCH] tty: fix crash in release_tty if tty->port is not set | Date | Thu, 5 Nov 2020 13:34:32 +0100 |
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Commit 2ae0b31e0face ("tty: don't crash in tty_init_dev when missing tty_port") didn't fully prevent the crash as the cleanup path in tty_init_dev() calls release_tty() which dereferences tty->port without checking it for non-null.
Add tty->port checks to release_tty to avoid the kernel crash.
Fixes: 2ae0b31e0face ("tty: don't crash in tty_init_dev when missing tty_port") Signed-off-by: Matthias Reichl <hias@horus.com> --- drivers/tty/tty_io.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 7a4c02548fb3f..9f8b9a567b359 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -1515,10 +1515,12 @@ static void release_tty(struct tty_struct *tty, int idx) tty->ops->shutdown(tty); tty_save_termios(tty); tty_driver_remove_tty(tty->driver, tty); - tty->port->itty = NULL; + if (tty->port) + tty->port->itty = NULL; if (tty->link) tty->link->port->itty = NULL; - tty_buffer_cancel_work(tty->port); + if (tty->port) + tty_buffer_cancel_work(tty->port); if (tty->link) tty_buffer_cancel_work(tty->link->port); -- 2.20.1
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