Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752681AbcKGVSc (ORCPT ); Mon, 7 Nov 2016 16:18:32 -0500 Received: from ch3vs01.rockwellcollins.com ([205.175.226.27]:43235 "EHLO ch3vs01.rockwellcollins.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752070AbcKGVSb (ORCPT ); Mon, 7 Nov 2016 16:18:31 -0500 X-Greylist: delayed 1919 seconds by postgrey-1.27 at vger.kernel.org; Mon, 07 Nov 2016 16:18:31 EST From: David Graziano To: golbi@mat.uni.torun.pl, michal.wronski@gmail.com Cc: linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, sds@tycho.nsa.gov, seth.forshee@canonical.com, ebiederm@xmission.com, David Graziano Subject: [PATCH 1/1 V2] mqueue: Implment generic xattr support Date: Mon, 7 Nov 2016 14:46:27 -0600 Message-Id: <1478551587-33892-1-git-send-email-david.graziano@rockwellcollins.com> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3003 Lines: 99 This patch adds support for generic extended attributes within the POSIX message queues filesystem and setting them by consulting the LSM. This is needed so that the security.selinux extended attribute can be set via a SELinux named type transition on file inodes created within the filesystem. The implementation and LSM call back function are based off tmpfs/shmem. Signed-off-by: David Graziano --- ipc/mqueue.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) diff --git a/ipc/mqueue.c b/ipc/mqueue.c index 0b13ace..512a546 100644 --- a/ipc/mqueue.c +++ b/ipc/mqueue.c @@ -35,6 +35,7 @@ #include #include #include +#include #include #include "util.h" @@ -70,6 +71,7 @@ struct mqueue_inode_info { struct rb_root msg_tree; struct posix_msg_tree_node *node_cache; struct mq_attr attr; + struct simple_xattrs xattrs; /* list of xattrs */ struct sigevent notify; struct pid *notify_owner; @@ -254,6 +256,7 @@ static struct inode *mqueue_get_inode(struct super_block *sb, info->attr.mq_maxmsg = attr->mq_maxmsg; info->attr.mq_msgsize = attr->mq_msgsize; } + simple_xattrs_init(&info->xattrs); /* * We used to allocate a static array of pointers and account * the size of that array as well as one msg_msg struct per @@ -413,6 +416,41 @@ static void mqueue_evict_inode(struct inode *inode) put_ipc_ns(ipc_ns); } +/* + * Callback for security_inode_init_security() for acquiring xattrs. + */ +static int mqueue_initxattrs(struct inode *inode, + const struct xattr *xattr_array, + void *fs_info) +{ + struct mqueue_inode_info *info = MQUEUE_I(inode); + const struct xattr *xattr; + struct simple_xattr *new_xattr; + size_t len; + + for (xattr = xattr_array; xattr->name != NULL; xattr++) { + new_xattr = simple_xattr_alloc(xattr->value, xattr->value_len); + if (!new_xattr) + return -ENOMEM; + len = strlen(xattr->name) + 1; + new_xattr->name = kmalloc(XATTR_SECURITY_PREFIX_LEN + len, + GFP_KERNEL); + if (!new_xattr->name) { + kfree(new_xattr); + return -ENOMEM; + } + + memcpy(new_xattr->name, XATTR_SECURITY_PREFIX, + XATTR_SECURITY_PREFIX_LEN); + memcpy(new_xattr->name + XATTR_SECURITY_PREFIX_LEN, + xattr->name, len); + + simple_xattr_list_add(&info->xattrs, new_xattr); + } + + return 0; +} + static int mqueue_create(struct inode *dir, struct dentry *dentry, umode_t mode, bool excl) { @@ -443,6 +481,14 @@ static int mqueue_create(struct inode *dir, struct dentry *dentry, ipc_ns->mq_queues_count--; goto out_unlock; } + error = security_inode_init_security(inode, dir, + &dentry->d_name, + mqueue_initxattrs, NULL); + if (error && error != -EOPNOTSUPP) { + spin_lock(&mq_lock); + ipc_ns->mq_queues_count--; + goto out_unlock; + } put_ipc_ns(ipc_ns); dir->i_size += DIRENT_SIZE; -- 1.9.1