powerpc/legacy_serial: Fix UBSAN: array-index-out-of-bounds

UBSAN complains when a pointer is calculated with invalid
'legacy_serial_console' index, allthough the index is verified
before dereferencing the pointer.

Fix it by checking 'legacy_serial_console' validity before
calculating pointers.

Fixes: 0bd3f9e953 ("powerpc/legacy_serial: Use early_ioremap()")
Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210511010712.750096-1-mpe@ellerman.id.au
This commit is contained in:
Christophe Leroy 2021-05-08 06:36:21 +00:00 committed by Michael Ellerman
parent bc581dbab2
commit 63970f3c37

View File

@ -356,13 +356,16 @@ static void __init setup_legacy_serial_console(int console)
static int __init ioremap_legacy_serial_console(void)
{
struct legacy_serial_info *info = &legacy_serial_infos[legacy_serial_console];
struct plat_serial8250_port *port = &legacy_serial_ports[legacy_serial_console];
struct plat_serial8250_port *port;
struct legacy_serial_info *info;
void __iomem *vaddr;
if (legacy_serial_console < 0)
return 0;
info = &legacy_serial_infos[legacy_serial_console];
port = &legacy_serial_ports[legacy_serial_console];
if (!info->early_addr)
return 0;