From: Shreyas Joshi <shreyas.joshi@xxxxxxxxx> [ 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@xxxxxxxxx Signed-off-by: Shreyas Joshi <shreyas.joshi@xxxxxxxxx> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx> [pmladek@xxxxxxxx: Better format the commit message and code, remove unnecessary brackets.] Signed-off-by: Petr Mladek <pmladek@xxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- kernel/printk/printk.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 4e50beb162c00..f96b22db5fe70 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -2092,6 +2092,9 @@ 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
