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@xxxxxxxxxxxxxxx # 3.7
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
---
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);
--
2.32.0
