Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756697Ab2HOVOB (ORCPT ); Wed, 15 Aug 2012 17:14:01 -0400 Received: from mga07.intel.com ([143.182.124.22]:17888 "EHLO azsmga101.ch.intel.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756303Ab2HOVN7 (ORCPT ); Wed, 15 Aug 2012 17:13:59 -0400 MIME-Version: 1.0 In-Reply-To: <20120815201635.GB10088@amd1> References: <68a6f647ca1d4429d6b781b6cfeed9c93a346c14.1345055639.git.dmitry.kasatkin@intel.com> <20120815201635.GB10088@amd1> Date: Thu, 16 Aug 2012 00:13:57 +0300 Message-ID: Subject: Re: [RFC v2 4/7] modsig: add integrity_module_check hook From: "Kasatkin, Dmitry" To: Serge Hallyn Cc: zohar@linux.vnet.ibm.com, jmorris@namei.org, rusty@rustcorp.com.au, dhowells@redhat.com, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2615 Lines: 83 On Wed, Aug 15, 2012 at 11:16 PM, Serge Hallyn wrote: > Quoting Dmitry Kasatkin (dmitry.kasatkin@intel.com): >> IMA measures/appraises modules when modprobe or insmod opens and read them. >> Unfortunately, there are no guarantees between what is read by userspace and >> what is passed to the kernel via load_module system call. This patch adds a >> hook called integrity_module_check() to verify the integrity of the module >> being loaded. >> >> Signed-off-by: Dmitry Kasatkin >> --- >> include/linux/integrity.h | 10 ++++++++++ >> kernel/module.c | 9 +++++++++ >> 2 files changed, 19 insertions(+) >> >> diff --git a/include/linux/integrity.h b/include/linux/integrity.h >> index 66c5fe9..a80ec06 100644 >> --- a/include/linux/integrity.h >> +++ b/include/linux/integrity.h >> @@ -37,4 +37,14 @@ static inline void integrity_inode_free(struct inode *inode) >> return; >> } >> #endif /* CONFIG_INTEGRITY_H */ >> + >> +#ifdef CONFIG_INTEGRITY_MODULES >> +int integrity_module_check(const void *hdr, const unsigned long len); > > sadly not bisect-safe, since integrity_module_check() is defined in > the next patch. > Ok.. Hooks come after implementation... Will swap. Thanks. >> +#else >> +static inline int integrity_module_check(const void *buf, unsigned long len) >> +{ >> + return 0; >> +} >> +#endif >> + >> #endif /* _LINUX_INTEGRITY_H */ >> diff --git a/kernel/module.c b/kernel/module.c >> index 4edbd9c..791da47 100644 >> --- a/kernel/module.c >> +++ b/kernel/module.c >> @@ -58,6 +58,7 @@ >> #include >> #include >> #include >> +#include >> >> #define CREATE_TRACE_POINTS >> #include >> @@ -2437,6 +2438,14 @@ static int copy_and_check(struct load_info *info, >> >> info->hdr = hdr; >> info->len = len; >> + >> + err = integrity_module_check(hdr, len); >> + if (err < 0) >> + goto free_hdr; >> + >> + /* cut signature tail */ >> + info->len = err; >> + >> return 0; >> >> free_hdr: >> -- >> 1.7.9.5 >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-security-module" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/