Date: Fri, 12 Mar 2004 11:07:25 -0500 From: Tom Rhodes <trhodes@FreeBSD.org> To: Ruslan Ermilov <ru@FreeBSD.org> Cc: security@FreeBSD.org Subject: Re: bin/64150: [PATCH] ls(1) coredumps when started via execve(2) with no argv. Message-ID: <20040312110725.698ebe20@localhost> In-Reply-To: <20040312154600.GC2235@ip.net.ua> References: <200403120922.i2C9M0jC002510@stud326.idi.ntnu.no> <20040312104914.GA52099@ip.net.ua> <20040312105730.GA99925@stud326.idi.ntnu.no> <20040312110657.GB52099@ip.net.ua> <20040312111526.GA14260@stack.nl> <20040312125820.GA8574@lum.celabo.org> <20040312154600.GC2235@ip.net.ua>
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On Fri, 12 Mar 2004 17:46:00 +0200 Ruslan Ermilov <ru@freebsd.org> wrote: > On Fri, Mar 12, 2004 at 06:58:20AM -0600, Jacques A. Vidrine wrote: > > On Fri, Mar 12, 2004 at 12:15:26PM +0100, Marc Olzheim wrote: > > > On Fri, Mar 12, 2004 at 01:06:57PM +0200, Ruslan Ermilov wrote: > > > > And the fact that optind is initially set to 1. I wonder what > > > > could be the implications for setuid programs. There could be > > > > quite unpredictable results, as the "argv" pointer is incorrectly > > > > advanced in this case, and at least several setuid programs that > > > > I've glanced at are vulnerable to this attack. > > > > > > See also: http://www.freebsd.org/cgi/query-pr.cgi?pr=33738 > > > > Thanks Ruslan, Marc, > > > > I think kern/33738 is on the money. I do not see any immediate > > ramifications, but for peace of mind I believe that exec should fail if > > the argument array pointer is NULL. > > > > I believe this would be consistent with the relevant standards: POSIX > > already requires (a) that the first argument ``should point to a > > filename that is associated with the process being started'' and (b) > > ``the last member of this array is a null pointer''--- i.e. the array > > pointer cannot be NULL. > > > As Garrett already pointed out in the PR log, have you considered this? > > http://www.opengroup.org/onlinepubs/007904975/functions/execve.html#tag_03_130_08 > > I'm happy with changing our behavior to Strictly Conforming for the > goods of security, and you? Will it 'break' anything? -- Tom Rhodes
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