From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:52241) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Swf0k-0001Os-Bv for qemu-devel@nongnu.org; Wed, 01 Aug 2012 15:55:15 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Swf0g-0007aY-5E for qemu-devel@nongnu.org; Wed, 01 Aug 2012 15:55:14 -0400 Received: from e24smtp04.br.ibm.com ([32.104.18.25]:41013) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Swf0f-0007Y9-Pc for qemu-devel@nongnu.org; Wed, 01 Aug 2012 15:55:10 -0400 Received: from /spool/local by e24smtp04.br.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 1 Aug 2012 16:55:06 -0300 Received: from d24relay02.br.ibm.com (d24relay02.br.ibm.com [9.13.184.26]) by d24dlp01.br.ibm.com (Postfix) with ESMTP id EC7323520052 for ; Wed, 1 Aug 2012 15:54:59 -0400 (EDT) Received: from d24av05.br.ibm.com (d24av05.br.ibm.com [9.18.232.44]) by d24relay02.br.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q71JsB7F35455046 for ; Wed, 1 Aug 2012 16:54:12 -0300 Received: from d24av05.br.ibm.com (loopback [127.0.0.1]) by d24av05.br.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q71Jt1CC001071 for ; Wed, 1 Aug 2012 16:55:02 -0300 From: Eduardo Otubo Date: Wed, 1 Aug 2012 16:54:51 -0300 Message-Id: Subject: [Qemu-devel] [PATCHv5 0/4] Sandboxing Qemu guests with Libseccomp List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: blauwirbel@gmail.com, pmoore@redhat.com, anthony@codemonkey.ws, wad@chromium.org, Eduardo Otubo Hello all, This patch is an effort to sandbox Qemu guests using Libseccomp[0]. The patches that follows are pretty simple and straightforward. I added the correct options and checks to the configure script and the basic calls to libseccomp in the main loop at vl.c. Details of each one are in the emails of the patch set. This support limits the system call footprint of the entire QEMU process to a limited set of syscalls, those that we know QEMU uses. The idea is to limit the allowable syscalls, therefore limiting the impact that an attacked guest could have on the host system. It's important to note that the libseccomp itself needs the seccomp mode 2 feature in the kernel, which is only available in kernel versions older (or equal) than 3.5-rc1. v2: Files separated in qemu-seccomp.c and qemu-seccomp.h for a cleaner implementation. The development was tested with the 3.5-rc1 kernel. v3: As we discussed in previous emails in this mailing list, this feature is not supposed to replace existing security feature, but add another layer to the whole. The whitelist should contain all the syscalls QEMU needs. And as stated by Will Drewry's commit message[1]: "Filter programs will be inherited across fork/clone and execve.", the same white list should be passed along from the father process to the child, then execve() shouldn't be a problem. Note that there's a feature PR_SET_NO_NEW_PRIVS in seccomp mode 2 in the kernel, this prevents processes from gaining privileges on execve. For example, this will prevent qemu (if running unprivileged) from executing setuid programs[2]. v4: Introducing "debug" mode on libseccomp support. The "debug" mode will set the flag SCMP_ACT_TRAP when calling seccomp_start(). It will verbosely print a message to the stderr in the form "seccomp: illegal system call execution trapped: XXX" and resume the execution. This is really just used as debug mode, it helps users and developers to full fill the whitelist. v5: Libseccomp release 1.0.0[3]: The API now is context aware and it breaks the compatibility with older versions. I updated all the functions that differs from one version to another. As always, comments are more than welcome. Regards, [0] - http://sourceforge.net/projects/libseccomp/ [1] - http://git.kernel.org/?p=linux/kernel/git/next/linux-next.git;a=commit;h=e2cfabdfd075648216f99c2c03821cf3f47c1727 [2] - https://lkml.org/lkml/2012/4/12/457 [3] - http://sourceforge.net/mailarchive/forum.php?thread_name=1633205.5jr3eG7nQ5%40sifl&forum_name=libseccomp-discuss Eduardo Otubo (4): Adding support for libseccomp in configure and Makefile Adding qemu-seccomp.[ch] Adding qemu-seccomp-debug.[ch] Adding seccomp calls to vl.c Makefile.objs | 10 ++++ configure | 34 ++++++++++++ qemu-seccomp-debug.c | 95 ++++++++++++++++++++++++++++++++++ qemu-seccomp-debug.h | 38 ++++++++++++++ qemu-seccomp.c | 139 ++++++++++++++++++++++++++++++++++++++++++++++++++ qemu-seccomp.h | 22 ++++++++ vl.c | 31 +++++++++++ 7 files changed, 369 insertions(+), 0 deletions(-) create mode 100644 qemu-seccomp-debug.c create mode 100644 qemu-seccomp-debug.h create mode 100644 qemu-seccomp.c create mode 100644 qemu-seccomp.h