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Date:   Tue, 13 Nov 2018 11:29:29 +0100
From:   Michal Hocko <mhocko@kernel.org>
To:     Oleg Nesterov <oleg@redhat.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Ben Woodard <woodard@redhat.com>,
        "Eric W. Biederman" <ebiederm@xmission.com>,
        Kees Cook <keescook@chromium.org>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] exec: increase BINPRM_BUF_SIZE to 256
Message-ID: <20181113102929.GO15120@dhcp22.suse.cz>
References: <20181112160931.GA28463@redhat.com>
 <20181112160956.GA28472@redhat.com>
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On Mon 12-11-18 17:09:56, Oleg Nesterov wrote:
> Large enterprise clients often times run applications out of networked
> file systems where the IT mandated layout of project volumes can end up
> leading to paths that are longer than 128 characters. Bumping this up to
> the next order of two solves this problem in all but the most egregious
> case while still fitting into a 512b slab.
> 
> Reported-by: Ben Woodard <woodard@redhat.com>
> Signed-off-by: Oleg Nesterov <oleg@redhat.com>

Acked-by: Michal Hocko <mhocko@suse.com>

Increasing it to a larger value wouldn't hurt but I wouldn't bind it to
the page size because the layout might change and result in higher order
request.

> ---
>  include/uapi/linux/binfmts.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/include/uapi/linux/binfmts.h b/include/uapi/linux/binfmts.h
> index 4abad03..689025d 100644
> --- a/include/uapi/linux/binfmts.h
> +++ b/include/uapi/linux/binfmts.h
> @@ -16,6 +16,6 @@ struct pt_regs;
>  #define MAX_ARG_STRINGS 0x7FFFFFFF
>  
>  /* sizeof(linux_binprm->buf) */
> -#define BINPRM_BUF_SIZE 128
> +#define BINPRM_BUF_SIZE 256
>  
>  #endif /* _UAPI_LINUX_BINFMTS_H */
> -- 
> 2.5.0
> 
> 

-- 
Michal Hocko
SUSE Labs