From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752230AbZGaQ7L (ORCPT ); Fri, 31 Jul 2009 12:59:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751732AbZGaQ7J (ORCPT ); Fri, 31 Jul 2009 12:59:09 -0400 Received: from mx2.redhat.com ([66.187.237.31]:50083 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751125AbZGaQ7H (ORCPT ); Fri, 31 Jul 2009 12:59:07 -0400 From: Eric Paris Subject: [PATCH -v4 1/3] Capabilities: move cap_file_mmap to commoncap.c To: linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, selinux@tycho.nsa.gov Cc: jwcart2@tycho.nsa.gov, eparis@redhat.com, sds@tycho.nsa.gov, spender@grsecurity.net, dwalsh@redhat.com, cl@linux-foundation.org, arjan@infradead.org, alan@lxorguk.ukuu.org.uk, kees@outflux.net, csellers@tresys.com, penguin-kernel@i-love.sakura.ne.jp, serue@us.ibm.com Date: Fri, 31 Jul 2009 12:53:58 -0400 Message-ID: <20090731165358.20992.14757.stgit@paris.rdu.redhat.com> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently we duplicate the mmap_min_addr test in cap_file_mmap and in security_file_mmap if !CONFIG_SECURITY. This patch moves cap_file_mmap into commoncap.c and then calls that function directly from security_file_mmap ifndef CONFIG_SECURITY like all of the other capability checks are done. Signed-off-by: Eric Paris Acked-by: Serge Hallyn --- include/linux/security.h | 7 ++++--- security/capability.c | 9 --------- security/commoncap.c | 30 ++++++++++++++++++++++++++++++ 3 files changed, 34 insertions(+), 12 deletions(-) diff --git a/include/linux/security.h b/include/linux/security.h index 1459091..963a48f 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -66,6 +66,9 @@ extern int cap_inode_setxattr(struct dentry *dentry, const char *name, extern int cap_inode_removexattr(struct dentry *dentry, const char *name); extern int cap_inode_need_killpriv(struct dentry *dentry); extern int cap_inode_killpriv(struct dentry *dentry); +extern int cap_file_mmap(struct file *file, unsigned long reqprot, + unsigned long prot, unsigned long flags, + unsigned long addr, unsigned long addr_only); extern int cap_task_fix_setuid(struct cred *new, const struct cred *old, int flags); extern int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, unsigned long arg4, unsigned long arg5); @@ -2197,9 +2200,7 @@ static inline int security_file_mmap(struct file *file, unsigned long reqprot, unsigned long addr, unsigned long addr_only) { - if ((addr < mmap_min_addr) && !capable(CAP_SYS_RAWIO)) - return -EACCES; - return 0; + return cap_file_mmap(file, reqprot, prot, flags, addr, addr_only); } static inline int security_file_mprotect(struct vm_area_struct *vma, diff --git a/security/capability.c b/security/capability.c index f218dd3..ec05730 100644 --- a/security/capability.c +++ b/security/capability.c @@ -330,15 +330,6 @@ static int cap_file_ioctl(struct file *file, unsigned int command, return 0; } -static int cap_file_mmap(struct file *file, unsigned long reqprot, - unsigned long prot, unsigned long flags, - unsigned long addr, unsigned long addr_only) -{ - if ((addr < mmap_min_addr) && !capable(CAP_SYS_RAWIO)) - return -EACCES; - return 0; -} - static int cap_file_mprotect(struct vm_area_struct *vma, unsigned long reqprot, unsigned long prot) { diff --git a/security/commoncap.c b/security/commoncap.c index aa97704..3852e94 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -984,3 +984,33 @@ int cap_vm_enough_memory(struct mm_struct *mm, long pages) cap_sys_admin = 1; return __vm_enough_memory(mm, pages, cap_sys_admin); } + +/* + * cap_file_mmap - check if able to map given addr + * @file: unused + * @reqprot: unused + * @prot: unused + * @flags: unused + * @addr: address attempting to be mapped + * @addr_only: unused + * + * If the process is attempting to map memory below mmap_min_addr they need + * CAP_SYS_RAWIO. The other parameters to this function are unused by the + * capability security module. Returns 0 if this mapping should be allowed + * -EPERM if not. + */ +int cap_file_mmap(struct file *file, unsigned long reqprot, + unsigned long prot, unsigned long flags, + unsigned long addr, unsigned long addr_only) +{ + int ret = 0; + + if (addr < mmap_min_addr) { + ret = cap_capable(current, current_cred(), CAP_SYS_RAWIO, + SECURITY_CAP_AUDIT); + /* set PF_SUPERPRIV if it turns out we allow the low mmap */ + if (ret == 0) + current->flags |= PF_SUPERPRIV; + } + return ret; +}