ipack: ipoctal: fix missing allocation-failure check

BugLink: https://bugs.launchpad.net/bugs/1947888
commit 445c8132727728dc297492a7d9fc074af3e94ba3 upstream.

Add the missing error handling when allocating the transmit buffer to
avoid dereferencing a NULL pointer in write() should the allocation
ever fail.

Fixes: ba4dc61fe8c5 ("Staging: ipack: add support for IP-OCTAL mezzanine board")
Cc: stable@vger.kernel.org      # 3.5
Acked-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210917114622.5412-5-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>

diff --git a/drivers/ipack/devices/ipoctal.c b/drivers/ipack/devices/ipoctal.c
index 498f52784c3ac8d5a16019c2fa77ca90ca4aa48e..e22696ebd406795e921f67a88d555e8de402a7db 100644 (file)
--- a/drivers/ipack/devices/ipoctal.c
+++ b/drivers/ipack/devices/ipoctal.c
@@ -388,7 +388,9 @@ static int ipoctal_inst_slot(struct ipoctal *ipoctal, unsigned int bus_nr,
 
                channel = &ipoctal->channel[i];
                tty_port_init(&channel->tty_port);
-               tty_port_alloc_xmit_buf(&channel->tty_port);
+               res = tty_port_alloc_xmit_buf(&channel->tty_port);
+               if (res)
+                       continue;
                channel->tty_port.ops = &ipoctal_tty_port_ops;
 
                ipoctal_reset_stats(&channel->stats);