From 63970f3c37e75997ed86dbdfdc83df35f2152bb1 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Sat, 8 May 2021 06:36:21 +0000 Subject: [PATCH] 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: 0bd3f9e953bd ("powerpc/legacy_serial: Use early_ioremap()") Reported-by: Paul Menzel Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210511010712.750096-1-mpe@ellerman.id.au --- arch/powerpc/kernel/legacy_serial.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/kernel/legacy_serial.c b/arch/powerpc/kernel/legacy_serial.c index 8b2c1a8553a0..cfc03e016ff2 100644 --- a/arch/powerpc/kernel/legacy_serial.c +++ b/arch/powerpc/kernel/legacy_serial.c @@ -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;