linux-kernel - Re: [PATCH] LSM: add NULL check for kcalloc()

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: <CADLLry6RmSDuB4nmVKDEiqxXmEU0xrhMn2wieuuVTypMWqc4cQ@mail.gmail.com>
Date:   Thu, 15 Jul 2021 06:44:52 +0900
From:   Austin Kim <austindh.kim@...il.com>
To:     James Morris <jmorris@...ei.org>
Cc:     "Serge E. Hallyn" <serge@...lyn.com>,
        Kees Cook <keescook@...omium.org>,
        linux-security-module <linux-security-module@...r.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        김동현 <austin.kim@....com>,
        kernel-team@....com
Subject: Re: [PATCH] LSM: add NULL check for kcalloc()

2021년 7월 15일 (목) 오전 4:12, James Morris <jmorris@...ei.org>님이 작성:
>
> On Tue, 13 Jul 2021, Austin Kim wrote:
>
> > From: Austin Kim <austin.kim@....com>
> >
> > kcalloc() may return NULL when memory allocation fails.
> > So it is necessary to add NULL check after the call to kcalloc() is made.
> >
> > Signed-off-by: Austin Kim <austin.kim@....com>
> > ---
> >  security/security.c | 2 ++
> >  1 file changed, 2 insertions(+)
> >
> > diff --git a/security/security.c b/security/security.c
> > index 09533cbb7221..f885c9e9bc35 100644
> > --- a/security/security.c
> > +++ b/security/security.c
> > @@ -321,6 +321,8 @@ static void __init ordered_lsm_init(void)
> >
> >       ordered_lsms = kcalloc(LSM_COUNT + 1, sizeof(*ordered_lsms),
> >                               GFP_KERNEL);
> > +     if (ordered_lsms)
> > +             return;
>
> Your logic is reversed here.

I feel very sorry for my terrible mistake.
'if (ordered_lsms)' should have been 'if (!ordered_lsms)'.

Let me resend patch(v2) soon.

Thanks,
Austin Kim

>
> Should this also be a kernel panic?
>
> >
> >       if (chosen_lsm_order) {
> >               if (chosen_major_lsm) {
> > --
> > 2.20.1
> >
>
> --
> James Morris
> <jmorris@...ei.org>
>