oss-sec mailing list archives
Re: glibc crypt(3), crypt_r(3), PHP crypt() may use alloca()
From: Solar Designer <solar () openwall com>
Date: Fri, 30 Mar 2012 22:17:25 +0400
Tomas - thank you for notifying oss-security of this. Jeff - thank you for working on a fix. On Fri, Mar 30, 2012 at 07:56:39PM +0200, Tomas Hoger wrote:
FYI, a fix just got committed upstream,
Wow. I thought we'd need to notify glibc developers more specifically for this to happen, which I did not do yet for lack of decision on what to do with the return value.
which makes glibc use malloc instead of alloca for long inputs and hence possibly make crypt() return NULL on errors: http://sourceware.org/git/?p=glibc.git;a=commitdiff;h=b8dc394ddfd58bc5d0fe9ecfc970fc42b789a9df Upstream discussion: http://sourceware.org/ml/libc-alpha/2012-03/msg01138.html http://sourceware.org/ml/libc-alpha/2012-03/msg01158.html
I think the NULL returns are a bad idea, and this aspect doesn't appear to have been discussed. We may want to check if there were other cases where glibc's crypt() could return NULL, then propose a separate patch on libc-alpha. So far, the "*0" / "*1" approach appears to be best: http://www.openwall.com/lists/oss-security/2011/11/15/1 Alexander
Current thread:
- Re: glibc crypt(3), crypt_r(3), PHP crypt() may use alloca() Tomas Hoger (Mar 30)
- Re: glibc crypt(3), crypt_r(3), PHP crypt() may use alloca() Solar Designer (Mar 30)
- Re: glibc crypt(3), crypt_r(3), PHP crypt() may use alloca() Jeff Law (Mar 30)
- Re: glibc crypt(3), crypt_r(3), PHP crypt() may use alloca() Solar Designer (Mar 30)
- Re: glibc crypt(3), crypt_r(3), PHP crypt() may use alloca() Jeff Law (Mar 30)
- Re: glibc crypt(3), crypt_r(3), PHP crypt() may use alloca() Solar Designer (Mar 30)
- Re: glibc crypt(3), crypt_r(3), PHP crypt() may use alloca() Jeff Law (Mar 30)
- Re: glibc crypt(3), crypt_r(3), PHP crypt() may use alloca() Jeff Law (Mar 30)
- Re: glibc crypt(3), crypt_r(3), PHP crypt() may use alloca() Solar Designer (Mar 30)