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authorJohan Hovold <johan@kernel.org>2021-09-17 13:46:19 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-09-27 17:38:49 +0200
commitcd20d59291d1790dc74248476e928f57fc455189 (patch)
tree14f18b1deff58dccf2ffb91c8fc28a906a3cc29c
parent65c001df517a7bf9be8621b53d43c89f426ce8d6 (diff)
ipack: ipoctal: fix tty-registration error handling
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 Acked-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com> Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20210917114622.5412-4-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/ipack/devices/ipoctal.c7
1 files changed, 7 insertions, 0 deletions
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);