From: Shreyas Joshi Date: Fri, 22 May 2020 06:53:06 +0000 (+1000) Subject: printk: handle blank console arguments passed in. X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=48021f98130880dd74;p=linux.git printk: handle blank console arguments passed in. If uboot passes a blank string to console_setup then it results in a trashed memory. Ultimately, the kernel crashes during freeing up the memory. This fix checks if there is a blank parameter being passed to console_setup from uboot. In case it detects that the console parameter is blank then it doesn't setup the serial device and it gracefully exits. Link: https://lore.kernel.org/r/20200522065306.83-1-shreyas.joshi@biamp.com Signed-off-by: Shreyas Joshi Acked-by: Sergey Senozhatsky [pmladek@suse.com: Better format the commit message and code, remove unnecessary brackets.] Signed-off-by: Petr Mladek --- diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 35cc5f5488603..a3990505abdf8 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -2200,6 +2200,9 @@ static int __init console_setup(char *str) char *s, *options, *brl_options = NULL; int idx; + if (str[0] == 0) + return 1; + if (_braille_console_setup(&str, &brl_options)) return 1;