linux-kernel - Re: [PATCH 2/2] livepatch: handle kzalloc failure

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: <20181213123306.g7ond2gy6vqq7sge@pathway.suse.cz>
Date:   Thu, 13 Dec 2018 13:33:06 +0100
From:   Petr Mladek <pmladek@...e.com>
To:     Nicholas Mc Guire <hofrat@...dl.org>
Cc:     Josh Poimboeuf <jpoimboe@...hat.com>, Jessica Yu <jeyu@...nel.org>,
        Jiri Kosina <jikos@...nel.org>,
        Miroslav Benes <mbenes@...e.cz>, live-patching@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/2] livepatch: handle kzalloc failure

On Thu 2018-12-13 12:09:50, Nicholas Mc Guire wrote:
> kzalloc() return should be checked. On dummy_alloc() failing
> in kzalloc() NULL should be returned.
> 
> Signed-off-by: Nicholas Mc Guire <hofrat@...dl.org>
> ---
> 
> Problem was located with an experimental coccinelle script
> 
> Patch was compile tested with: x86_64_defconfig + FTRACE=y
> FUNCTION_TRACER=y, EXPERT=y, LATENCYTOP=y, SAMPLES=y, SAMPLE_LIVEPATCH=y
> (with a number of unrelated sparse warnings on symbols not being static)
> 
> Patch is against 4.20-rc6 (localversion-next is next-20181213)
> 
>  samples/livepatch/livepatch-shadow-mod.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/samples/livepatch/livepatch-shadow-mod.c b/samples/livepatch/livepatch-shadow-mod.c
> index 4c54b25..57d5cde 100644
> --- a/samples/livepatch/livepatch-shadow-mod.c
> +++ b/samples/livepatch/livepatch-shadow-mod.c
> @@ -118,6 +118,8 @@ noinline struct dummy *dummy_alloc(void)
>  
>  	/* Oops, forgot to save leak! */
>  	leak = kzalloc(sizeof(int), GFP_KERNEL);
> +	if (!leak)
> +		return NULL;

The same comments apply here as for PATCH 1/2.

Best Regards,
Petr