linux-kernel - Re: [PATCH 1/1] fanotify: check permissions when creating file descriptor

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] [day] [month] [year] [list]

Message-ID: <CAKgNAki+0VTA53ibaZy0e-Qt6STpUBsbQKMAUHr1ePd3hJPg7Q@mail.gmail.com>
Date:	Thu, 24 Apr 2014 18:14:48 +0200
From:	"Michael Kerrisk (man-pages)" <mtk.manpages@...il.com>
To:	Jan Kara <jack@...e.cz>
Cc:	Heinrich Schuchardt <xypron.glpk@....de>,
	Eric Paris <eparis@...hat.com>,
	lkml <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 1/1] fanotify: check permissions when creating file descriptor

>> This means a listener may have read authorization for /home and mark
>> this mount.
>> Afterwards, while you sign a git tag, it will receive a FAN_OPEN event
>> and use the file descriptor supplied in the event to overwrite your
>> /home/jankara/.gnupg/secring.pgp
>> though the file is chmod 600 and the listener is neither root nor you.
>   Ah, right. Thanks for explaining this to me. I'm not really too excited
> about this as a security issue because once the process has CAP_SYS_ADMIN
> it basically owns the machine (it is sadly one of those capabilities which
> is too broad)

Yup. https://lwn.net/Articles/486306/

> but I agree checking permissions when creating the fd is
> reasonable.
>
>                                                                 Honza
> --
> Jan Kara <jack@...e.cz>
> SUSE Labs, CR



-- 
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/
--
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/