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From: Vasiliy Kulikov <segoon@openwall.com>
To: musl@lists.openwall.com
Subject: Re: LD_PRELOAD and RTLD_NEXT support
Date: Tue, 16 Aug 2011 10:34:10 +0400	[thread overview]
Message-ID: <20110816063410.GA4254@albatros> (raw)
In-Reply-To: <20110816051715.GN132@brightrain.aerifal.cx>

Rich,

On Tue, Aug 16, 2011 at 01:17 -0400, Rich Felker wrote:
> (fully disabled for any suid/sgid binary)

        if ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
          || aux[AT_GID]!=aux[AT_EGID]) {

Two things here:

1) This check should be extended to support AT_SECURE (dumpable flag,
any LSM security domains, capabilities).

2) As you check for (aux[0] & 0x7800) you assume some of these elements
can be absent.  I feel it's wrong to assume you're not s*id'ed in this
case.  Instead, it's better to check for (getuid()!=geteuid() ||
getgid()!=getegid()).

Thanks,

-- 
Vasiliy


  reply	other threads:[~2011-08-16  6:34 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-08-16  5:17 Rich Felker
2011-08-16  6:34 ` Vasiliy Kulikov [this message]
2011-08-16 11:47   ` Rich Felker
2011-08-16 12:46     ` Vasiliy Kulikov
2011-08-16 12:59       ` Rich Felker
2011-08-22 17:02       ` env vars in SUID/SGID programs (was: LD_PRELOAD and RTLD_NEXT support) Solar Designer
2011-08-22 18:13         ` Rich Felker

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