linux-kernel - Re: "Switch !O_CREAT case to use of do

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]

Date:	Sat, 6 Mar 2010 18:24:30 +0000
From:	Al Viro <viro@...IV.linux.org.uk>
To:	walt <w41ter@...il.com>
Cc:	linux-kernel@...r.kernel.org
Subject: Re: "Switch !O_CREAT case to use of do_last()" causes segfault in
 glibc

On Sat, Mar 06, 2010 at 10:20:41AM -0800, walt wrote:
> On 03/06/2010 10:03 AM, Al Viro wrote:
> 
> >_Really_ interesting; it doesn't look like an oops - smells like an attempt
> >to do opendir() that fails for some reason, goes unnoticed and resulting
> >FILE * (i.e. NULL) is fed to readdir()?
> >
> >What does it attempt to open?
> 
> Ah, this may help:
> 
> open("/usr/share/zoneinfo/", O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 47
> open("/usr/share/zoneinfo/MST7MDT", O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 48
> open("/usr/share/zoneinfo/MST7MDT/", O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = -1 ENOTDIR (Not a directory)
> --- SIGSEGV (Segmentation fault) @ 0 (0) ---

Oho...  And what do you have in /usr/share/zoneinfo?  I.e. what is MST7MDT?

BTW, icu is buggy, regardless of apparent bug introduced in the kernel -
common/putil.c:searchForTZFile() does

    DIR* dirp = opendir(path);
...
    while((dirEntry = readdir(dirp)) != NULL) {

with no references to dirp in between (no checks for errors, etc.), so it'll
segfault on any number of situations (e.g. directory in question being
unreadable for you).
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/