From fad70e4c2dd6bc7c8cb9c3a61cb1dafad96a359e Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Tue, 19 Mar 2013 09:21:17 +0100 Subject: [PATCH] USB: io_ti: fix use-after-free in TIOCMIWAIT commit 7b2459690584f239650a365f3411ba2ec1c6d1e0 upstream. Use the port wait queue and make sure to check the serial disconnected flag before accessing private port data after waking up. This is is needed as the private port data (including the wait queue itself) can be gone when waking up after a disconnect. Signed-off-by: Johan Hovold Signed-off-by: Ben Hutchings Cc: Yang Yingliang Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/io_ti.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/usb/serial/io_ti.c b/drivers/usb/serial/io_ti.c index b68efdc38ef..64eb8799f1e 100644 --- a/drivers/usb/serial/io_ti.c +++ b/drivers/usb/serial/io_ti.c @@ -91,9 +91,6 @@ struct edgeport_port { int close_pending; int lsr_event; struct async_icount icount; - wait_queue_head_t delta_msr_wait; /* for handling sleeping while - waiting for msr change to - happen */ struct edgeport_serial *edge_serial; struct usb_serial_port *port; __u8 bUartMode; /* Port type, 0: RS232, etc. */ @@ -1549,7 +1546,7 @@ static void handle_new_msr(struct edgeport_port *edge_port, __u8 msr) icount->dcd++; if (msr & EDGEPORT_MSR_DELTA_RI) icount->rng++; - wake_up_interruptible(&edge_port->delta_msr_wait); + wake_up_interruptible(&edge_port->port->delta_msr_wait); } /* Save the new modem status */ @@ -1867,7 +1864,6 @@ static int edge_open(struct tty_struct *tty, struct usb_serial_port *port) dev = port->serial->dev; memset(&(edge_port->icount), 0x00, sizeof(edge_port->icount)); - init_waitqueue_head(&edge_port->delta_msr_wait); /* turn off loopback */ status = ti_do_config(edge_port, UMPC_SET_CLR_LOOPBACK, 0); @@ -2553,10 +2549,14 @@ static int edge_ioctl(struct tty_struct *tty, dbg("%s - (%d) TIOCMIWAIT", __func__, port->number); cprev = edge_port->icount; while (1) { - interruptible_sleep_on(&edge_port->delta_msr_wait); + interruptible_sleep_on(&port->delta_msr_wait); /* see if a signal did it */ if (signal_pending(current)) return -ERESTARTSYS; + + if (port->serial->disconnected) + return -EIO; + cnow = edge_port->icount; if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr && cnow.dcd == cprev.dcd && cnow.cts == cprev.cts) -- 2.34.1