From: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
To: David Dgien <dgienda125@gmail.com>
Cc: barebox@lists.infradead.org
Subject: Re: [PATCH] password: Fix warning with empty default password
Date: Wed, 20 May 2020 08:26:32 +0200 [thread overview]
Message-ID: <20200520062632.hfbmedgtofv6y665@pengutronix.de> (raw)
In-Reply-To: <20200520035555.84422-1-dgienda125@gmail.com>
On Tue, May 19, 2020 at 11:55:55PM -0400, David Dgien wrote:
> When CONFIG_PASSWORD_DEFAULT is unset, the default_passwd buffer is set
I assume you mean "If CONFIG_PASSWORD_DEFAULT is set to an empty
string".
> to the empty string. The read_default_passwd() function wants to read at
> least two characters from that buffer, causing GCC to generate an array
> bounds warning.
I cannot reproduce that warning. Which gcc version do you use and on
which platform? Mentioning the exact warning in the commit log helps
finding the resulting commit when searching for a fix.
> Make the default_passwd buffer have at least 2 bytes so
> this warning is not generated.
>
> Since the read_default_passwd() function is only called when
> default_passwd is not the empty string, this is not a functional change.
I don't understand the problem for the empty password. With
default_passwd = "" we have strlen(default_passwd) = 0 so the for loop
doesn't run at all.
As I understand the code (at commit c10b20dc83ac) for uneven lengths of
default_passwd the last accessed byte is the trailing '\0' and for even
length it's the byte before the trailing '\0'. This should be ok?!
Am I missing something?
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | https://www.pengutronix.de/ |
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next prev parent reply other threads:[~2020-05-20 6:26 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-20 3:55 David Dgien
2020-05-20 6:26 ` Uwe Kleine-König [this message]
2020-05-21 3:04 ` David Dgien
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