linux-kernel - Re: [PATCH] mm/khugepaged: Initialize index and nr in collapse

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20221025184802.7d4611caff603fecf98330b6@linux-foundation.org>
Date:   Tue, 25 Oct 2022 18:48:02 -0700
From:   Andrew Morton <akpm@...ux-foundation.org>
To:     Nathan Chancellor <nathan@...nel.org>
Cc:     Gautam Menghani <gautammenghani201@...il.com>,
        Nick Desaulniers <ndesaulniers@...gle.com>,
        Tom Rix <trix@...hat.com>, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org, llvm@...ts.linux.dev,
        patches@...ts.linux.dev, kernel test robot <lkp@...el.com>
Subject: Re: [PATCH] mm/khugepaged: Initialize index and nr in
 collapse_file()

On Tue, 25 Oct 2022 10:34:07 -0700 Nathan Chancellor <nathan@...nel.org> wrote:

> Clang warns (trimmed for brevity):
> 
>   mm/khugepaged.c:1729:7: warning: variable 'index' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
>   mm/khugepaged.c:1716:6: warning: variable 'index' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
>   mm/khugepaged.c:1729:7: warning: variable 'nr' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
>   mm/khugepaged.c:1716:6: warning: variable 'nr' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
> 
> There are two goto statements that will use index and nr before they
> have been properly initialized. Zero initialize them so that they can be
> safely used by the tracepoint at the end of the function.

Thanks.  I've actually dropped the offending patch - I'd like a resend
which includes a fix such as this and a good reason for making the
change.