diff options
| author | Fabio Estevam <fabio.estevam@nxp.com> | 2016-05-20 04:59:54 (GMT) |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-06-25 17:40:33 (GMT) |
| commit | a7cfaf165ed0f0b1e5e8636f9f28843b2b90139a (patch) | |
| tree | 95b114e5cceb1064c9ce2a9eb020dd2cb5ad2ab3 /drivers/tty | |
| parent | 3e5af8e04a3b104b6a8ccca4ff33644b5bcc21f0 (diff) | |
| download | linux-a7cfaf165ed0f0b1e5e8636f9f28843b2b90139a.tar.xz | |
serial: serial_core: Perform NULL checks for release/request_port ops
Doing the following UART bind/unbind sequence on a i.mx platform causes
a kernel crash due to NULL pointer dereference:
echo 21f4000.serial > /sys/bus/platform/drivers/imx-uart/bind
echo 21f4000.serial > /sys/bus/platform/drivers/imx-uart/unbind
Fix this problem by adding NULL checks prior to calling release/request_port
ops.
Reported-by: Fugang Duan <fugang.duan@nxp.com>
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Tested-by: Fugang Duan <fugang.duan@nxp.com>
Acked-by: Fugang Duan <fugang.duan@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/serial_core.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index a333c59..9fc1533 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -887,7 +887,7 @@ static int uart_set_info(struct tty_struct *tty, struct tty_port *port, /* * Free and release old regions */ - if (old_type != PORT_UNKNOWN) + if (old_type != PORT_UNKNOWN && uport->ops->release_port) uport->ops->release_port(uport); uport->iobase = new_port; @@ -900,7 +900,7 @@ static int uart_set_info(struct tty_struct *tty, struct tty_port *port, /* * Claim and map the new regions */ - if (uport->type != PORT_UNKNOWN) { + if (uport->type != PORT_UNKNOWN && uport->ops->request_port) { retval = uport->ops->request_port(uport); } else { /* Always success - Jean II */ @@ -1125,7 +1125,7 @@ static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state) * If we already have a port type configured, * we must release its resources. */ - if (uport->type != PORT_UNKNOWN) + if (uport->type != PORT_UNKNOWN && uport->ops->release_port) uport->ops->release_port(uport); flags = UART_CONFIG_TYPE; @@ -2897,7 +2897,7 @@ int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport) /* * Free the port IO and memory resources, if any. */ - if (uport->type != PORT_UNKNOWN) + if (uport->type != PORT_UNKNOWN && uport->ops->release_port) uport->ops->release_port(uport); kfree(uport->tty_groups); |