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Date:   Sun, 27 Sep 2020 14:29:09 +0200
From:   Greg KH <gregkh@linuxfoundation.org>
To:     Jim Cromie <jim.cromie@gmail.com>
Cc:     jbaron@akamai.com, linux-kernel@vger.kernel.org,
        Petr Mladek <pmladek@suse.com>
Subject: Re: [PATCH 1/2] dyndbg: dont panic over bad input
Message-ID: <20200927122909.GA186979@kroah.com>
References: <20200921190433.1149521-1-jim.cromie@gmail.com>
 <20200921190433.1149521-2-jim.cromie@gmail.com>
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In-Reply-To: <20200921190433.1149521-2-jim.cromie@gmail.com>
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On Mon, Sep 21, 2020 at 01:04:32PM -0600, Jim Cromie wrote:
> This BUG_ON, from 2009, caught the impossible case of a word-char both
> starting and ending a string (loosely speaking).  A bad (reverted)
> patch finally hit this case, but even "impossibly bad input" is no
> reason to panic the kernel.  Instead pr_err and return -EINVAL.
> 
> Reported-by: Petr Mladek <pmladek@suse.com>
> Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
> ---
>  lib/dynamic_debug.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
> index 2d4dfd44b0fa5..90ddf07ce34fe 100644
> --- a/lib/dynamic_debug.c
> +++ b/lib/dynamic_debug.c
> @@ -259,7 +259,10 @@ static int ddebug_tokenize(char *buf, char *words[], int maxwords)
>  		} else {
>  			for (end = buf; *end && !isspace(*end); end++)
>  				;
> -			BUG_ON(end == buf);
> +			if (end == buf) {
> +				pr_err("expected non-empty bareword");

Need a "\n" here, right?

thanks,

greg k-h