Registration of the ipoctal tty devices is unlikely to fail, but if it ever does, make sure not to deregister a never registered tty device (and dereference a NULL pointer) when the driver is later unbound.
Fixes: 2afb41d9d30d ("Staging: ipack/devices/ipoctal: Check tty_register_device return value.") Cc: stable@vger.kernel.org # 3.7 Signed-off-by: Johan Hovold johan@kernel.org --- drivers/ipack/devices/ipoctal.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/drivers/ipack/devices/ipoctal.c b/drivers/ipack/devices/ipoctal.c index 262451343127..d6875aa6a295 100644 --- a/drivers/ipack/devices/ipoctal.c +++ b/drivers/ipack/devices/ipoctal.c @@ -33,6 +33,7 @@ struct ipoctal_channel { unsigned int pointer_read; unsigned int pointer_write; struct tty_port tty_port; + bool tty_registered; union scc2698_channel __iomem *regs; union scc2698_block __iomem *block_regs; unsigned int board_id; @@ -396,9 +397,11 @@ static int ipoctal_inst_slot(struct ipoctal *ipoctal, unsigned int bus_nr, i, NULL, channel, NULL); if (IS_ERR(tty_dev)) { dev_err(&ipoctal->dev->dev, "Failed to register tty device.\n"); + tty_port_free_xmit_buf(&channel->tty_port); tty_port_destroy(&channel->tty_port); continue; } + channel->tty_registered = true; }
/* @@ -698,6 +701,10 @@ static void __ipoctal_remove(struct ipoctal *ipoctal)
for (i = 0; i < NR_CHANNELS; i++) { struct ipoctal_channel *channel = &ipoctal->channel[i]; + + if (!channel->tty_registered) + continue; + tty_unregister_device(ipoctal->tty_drv, i); tty_port_free_xmit_buf(&channel->tty_port); tty_port_destroy(&channel->tty_port);