x86: io delay - add checking for NULL early param

[ Upstream commit d6cd7effcc5e0047faf15ab0a54c980f1a616a07 ]

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: akpm@linux-foundation.org
Cc: andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
CC: Oliver Pinter <oliver.pntr@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/arch/x86/kernel/io_delay.c b/arch/x86/kernel/io_delay.c
index 5921e5f0a64027745fa2ac3e5f695ceaca9ddeae..1c3a66a67f83d3bb6d7eec2d5e4cfb1560660720 100644 (file)
--- a/arch/x86/kernel/io_delay.c
+++ b/arch/x86/kernel/io_delay.c
@@ -103,6 +103,9 @@ void __init io_delay_init(void)
 
 static int __init io_delay_param(char *s)
 {
+       if (!s)
+               return -EINVAL;
+
        if (!strcmp(s, "0x80"))
                io_delay_type = CONFIG_IO_DELAY_TYPE_0X80;
        else if (!strcmp(s, "0xed"))