From: Shreyas Joshi <shreyas.joshi@biamp.com> stable inclusion from linux-4.19.149 commit c6a9585611a538466c8ad2421035c0ffa7fabc77 -------------------------------- [ Upstream commit 48021f98130880dd74286459a1ef48b5e9bc374f ] 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 <shreyas.joshi@biamp.com> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> [pmladek@suse.com: Better format the commit message and code, remove unnecessary brackets.] Signed-off-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- kernel/printk/printk.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index c93b9cef8148..79158fc8e578 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -2172,6 +2172,9 @@ 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; -- 2.25.1