From: Johan Hovold <johan@xxxxxxxxxx> 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@xxxxxxxxxxxxxxx # 3.5 Acked-by: Samuel Iglesias Gonsalvez <siglesias@xxxxxxxxxx> Signed-off-by: Johan Hovold <johan@xxxxxxxxxx> Link: https://lore.kernel.org/r/20210917114622.5412-5-johan@xxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/ipack/devices/ipoctal.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/drivers/ipack/devices/ipoctal.c +++ b/drivers/ipack/devices/ipoctal.c @@ -386,7 +386,9 @@ static int ipoctal_inst_slot(struct ipoc 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);