From: Shreyas Joshi shreyas.joshi@biamp.com
stable inclusion from linux-4.19.149 commit c6a9585611a538466c8ad2421035c0ffa7fabc77
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[ 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;