[PATCH] term/ns8250: return in case of a null SPCR base addresses

[Leo Sandoval]

Serial SPCR MMIO null address are invalid, so return from function, otherwise
invalid 'mmio,0' port names are generated halting the system when running
terminal_input|output commands.

Signed-off-by: Leo Sandoval <lsandova@redhat.com>
---
 grub-core/term/ns8250.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/grub-core/term/ns8250.c b/grub-core/term/ns8250.c
index 23e8e0904..4ac0bc06a 100644
--- a/grub-core/term/ns8250.c
+++ b/grub-core/term/ns8250.c
@@ -407,6 +407,9 @@ grub_serial_ns8250_add_mmio (grub_addr_t addr, unsigned int 
acc_size,
   struct grub_serial_port *p;
   unsigned i;
 
+  if (addr == NULL)
+    return NULL;
+
   for (i = 0; i < GRUB_SERIAL_PORT_NUM; i++)
     if (com_ports[i].use_mmio == true && com_ports[i].mmio.base == addr)
       {
-- 
2.47.0