From patchwork Sat Oct 21 13:45:58 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicolas Belouin X-Patchwork-Id: 10021427 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id B2FF8603B5 for ; Sat, 21 Oct 2017 14:02:07 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9A7FB28964 for ; Sat, 21 Oct 2017 14:02:07 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8ECC028BD3; Sat, 21 Oct 2017 14:02:07 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.wl.linuxfoundation.org (Postfix) with SMTP id 5BF6B28964 for ; Sat, 21 Oct 2017 14:02:06 +0000 (UTC) Received: (qmail 15658 invoked by uid 550); 21 Oct 2017 14:01:54 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Delivered-To: mailing list kernel-hardening@lists.openwall.com Delivered-To: moderator for kernel-hardening@lists.openwall.com Received: (qmail 28578 invoked from network); 21 Oct 2017 13:47:47 -0000 From: Nicolas Belouin To: Jan Kara , "Theodore Ts'o" , Andreas Dilger , Jaegeuk Kim , Chao Yu , David Woodhouse , Dave Kleikamp , Mark Fasheh , Joel Becker , Miklos Szeredi , Phillip Lougher , Richard Weinberger , Artem Bityutskiy , Adrian Hunter , Alexander Viro , Serge Hallyn , Paul Moore , Stephen Smalley , Eric Paris , James Morris , linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-fsdevel@vger.kernel.org, linux-mtd@lists.infradead.org, jfs-discussion@lists.sourceforge.net, ocfs2-devel@oss.oracle.com, linux-unionfs@vger.kernel.org, reiserfs-devel@vger.kernel.org, linux-security-module@vger.kernel.org, selinux@tycho.nsa.gov, linux-api@vger.kernel.org, kernel-hardening@lists.openwall.com Cc: Nicolas Belouin Date: Sat, 21 Oct 2017 15:45:58 +0200 Message-Id: <20171021134558.21195-2-nicolas@belouin.fr> X-Mailer: git-send-email 2.14.2 In-Reply-To: <20171021134558.21195-1-nicolas@belouin.fr> References: <20171021134558.21195-1-nicolas@belouin.fr> X-Antivirus: Dr.Web (R) for Unix mail servers drweb plugin ver.6.0.2.8 X-Antivirus-Code: 0x100000 Subject: [kernel-hardening] [RFC PATCH 2/2] fs: Grant CAP_TRUSTED rw access to trusted xattrs X-Virus-Scanned: ClamAV using ClamSMTP The trusted xattrs read/write access is the perfect use case for CAP_TRUSTED. Signed-off-by: Nicolas Belouin --- fs/ext2/xattr_trusted.c | 2 +- fs/ext4/xattr_trusted.c | 2 +- fs/f2fs/xattr.c | 6 +++--- fs/hfsplus/xattr.c | 2 +- fs/jffs2/xattr_trusted.c | 2 +- fs/jfs/xattr.c | 3 ++- fs/ocfs2/xattr.c | 2 +- fs/overlayfs/inode.c | 3 ++- fs/reiserfs/xattr_trusted.c | 11 ++++++++--- fs/squashfs/xattr.c | 2 +- fs/ubifs/xattr.c | 3 ++- fs/xattr.c | 4 ++-- 12 files changed, 25 insertions(+), 17 deletions(-) diff --git a/fs/ext2/xattr_trusted.c b/fs/ext2/xattr_trusted.c index 65049b71af13..8006c24f8ee0 100644 --- a/fs/ext2/xattr_trusted.c +++ b/fs/ext2/xattr_trusted.c @@ -11,7 +11,7 @@ static bool ext2_xattr_trusted_list(struct dentry *dentry) { - return capable(CAP_SYS_ADMIN); + return capable(CAP_SYS_ADMIN) || capable(CAP_TRUSTED); } static int diff --git a/fs/ext4/xattr_trusted.c b/fs/ext4/xattr_trusted.c index c7765c735714..9849d1e0ebb9 100644 --- a/fs/ext4/xattr_trusted.c +++ b/fs/ext4/xattr_trusted.c @@ -15,7 +15,7 @@ static bool ext4_xattr_trusted_list(struct dentry *dentry) { - return capable(CAP_SYS_ADMIN); + return capable(CAP_SYS_ADMIN) || capable(CAP_TRUSTED); } static int diff --git a/fs/f2fs/xattr.c b/fs/f2fs/xattr.c index 7c65540148f8..ef572464deca 100644 --- a/fs/f2fs/xattr.c +++ b/fs/f2fs/xattr.c @@ -37,7 +37,7 @@ static int f2fs_xattr_generic_get(const struct xattr_handler *handler, return -EOPNOTSUPP; break; case F2FS_XATTR_INDEX_TRUSTED: - if (!capable(CAP_SYS_ADMIN)) + if (!capable(CAP_SYS_ADMIN) && !capable(CAP_TRUSTED)) return -EPERM; break; case F2FS_XATTR_INDEX_SECURITY: @@ -62,7 +62,7 @@ static int f2fs_xattr_generic_set(const struct xattr_handler *handler, return -EOPNOTSUPP; break; case F2FS_XATTR_INDEX_TRUSTED: - if (!capable(CAP_SYS_ADMIN)) + if (!capable(CAP_SYS_ADMIN) && !capable(CAP_TRUSTED)) return -EPERM; break; case F2FS_XATTR_INDEX_SECURITY: @@ -83,7 +83,7 @@ static bool f2fs_xattr_user_list(struct dentry *dentry) static bool f2fs_xattr_trusted_list(struct dentry *dentry) { - return capable(CAP_SYS_ADMIN); + return capable(CAP_SYS_ADMIN) || capable(CAP_TRUSTED); } static int f2fs_xattr_advise_get(const struct xattr_handler *handler, diff --git a/fs/hfsplus/xattr.c b/fs/hfsplus/xattr.c index ae03a19196ef..0ec6d02ee7e9 100644 --- a/fs/hfsplus/xattr.c +++ b/fs/hfsplus/xattr.c @@ -606,7 +606,7 @@ static inline int can_list(const char *xattr_name) return !strncmp(xattr_name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN) || - capable(CAP_SYS_ADMIN); + capable(CAP_SYS_ADMIN) || capable(CAP_TRUSTED); } static ssize_t hfsplus_listxattr_finder_info(struct dentry *dentry, diff --git a/fs/jffs2/xattr_trusted.c b/fs/jffs2/xattr_trusted.c index 5d6030826c52..3c7ae98e4525 100644 --- a/fs/jffs2/xattr_trusted.c +++ b/fs/jffs2/xattr_trusted.c @@ -35,7 +35,7 @@ static int jffs2_trusted_setxattr(const struct xattr_handler *handler, static bool jffs2_trusted_listxattr(struct dentry *dentry) { - return capable(CAP_SYS_ADMIN); + return capable(CAP_SYS_ADMIN) || capable(CAP_TRUSTED); } const struct xattr_handler jffs2_trusted_xattr_handler = { diff --git a/fs/jfs/xattr.c b/fs/jfs/xattr.c index 1c46573a96ed..e4f44f5133a1 100644 --- a/fs/jfs/xattr.c +++ b/fs/jfs/xattr.c @@ -859,7 +859,8 @@ ssize_t __jfs_getxattr(struct inode *inode, const char *name, void *data, static inline int can_list(struct jfs_ea *ea) { return (!strncmp(ea->name, XATTR_TRUSTED_PREFIX, - XATTR_TRUSTED_PREFIX_LEN) || capable(CAP_SYS_ADMIN)); + XATTR_TRUSTED_PREFIX_LEN) || + capable(CAP_SYS_ADMIN) || capable(CAP_TRUSTED)); } ssize_t jfs_listxattr(struct dentry * dentry, char *data, size_t buf_size) diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c index 5fdf269ba82e..2b3994d192c6 100644 --- a/fs/ocfs2/xattr.c +++ b/fs/ocfs2/xattr.c @@ -906,7 +906,7 @@ static int ocfs2_xattr_list_entry(struct super_block *sb, break; case OCFS2_XATTR_INDEX_TRUSTED: - if (!capable(CAP_SYS_ADMIN)) + if (!capable(CAP_SYS_ADMIN) && !capable(CAP_TRUSTED)) return 0; break; } diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index a619addecafc..c627003d3a74 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -264,7 +264,8 @@ static bool ovl_can_list(const char *s) return true; /* Never list trusted.overlay, list other trusted for superuser only */ - return !ovl_is_private_xattr(s) && capable(CAP_SYS_ADMIN); + return !ovl_is_private_xattr(s) && + (capable(CAP_SYS_ADMIN) || capable(CAP_TRUSTED)); } ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size) diff --git a/fs/reiserfs/xattr_trusted.c b/fs/reiserfs/xattr_trusted.c index f15a5f9e84ce..6f3fa0db8272 100644 --- a/fs/reiserfs/xattr_trusted.c +++ b/fs/reiserfs/xattr_trusted.c @@ -7,11 +7,16 @@ #include "xattr.h" #include +inline bool trusted_capable(void) +{ + return capable(CAP_SYS_ADMIN) || capable(CAP_TRUSTED); +} + static int trusted_get(const struct xattr_handler *handler, struct dentry *unused, struct inode *inode, const char *name, void *buffer, size_t size) { - if (!capable(CAP_SYS_ADMIN) || IS_PRIVATE(inode)) + if (!trusted_capable() || IS_PRIVATE(inode)) return -EPERM; return reiserfs_xattr_get(inode, xattr_full_name(handler, name), @@ -23,7 +28,7 @@ trusted_set(const struct xattr_handler *handler, struct dentry *unused, struct inode *inode, const char *name, const void *buffer, size_t size, int flags) { - if (!capable(CAP_SYS_ADMIN) || IS_PRIVATE(inode)) + if (!trusted_capable() || IS_PRIVATE(inode)) return -EPERM; return reiserfs_xattr_set(inode, @@ -33,7 +38,7 @@ trusted_set(const struct xattr_handler *handler, struct dentry *unused, static bool trusted_list(struct dentry *dentry) { - return capable(CAP_SYS_ADMIN) && !IS_PRIVATE(d_inode(dentry)); + return trusted_capable() && !IS_PRIVATE(d_inode(dentry)); } const struct xattr_handler reiserfs_xattr_trusted_handler = { diff --git a/fs/squashfs/xattr.c b/fs/squashfs/xattr.c index 1548b3784548..e0a285ab1f7e 100644 --- a/fs/squashfs/xattr.c +++ b/fs/squashfs/xattr.c @@ -237,7 +237,7 @@ static const struct xattr_handler squashfs_xattr_user_handler = { */ static bool squashfs_trusted_xattr_handler_list(struct dentry *d) { - return capable(CAP_SYS_ADMIN); + return capable(CAP_SYS_ADMIN) || capable(CAP_TRUSTED); } static const struct xattr_handler squashfs_xattr_trusted_handler = { diff --git a/fs/ubifs/xattr.c b/fs/ubifs/xattr.c index c13eae819cbc..f3aa8be72a66 100644 --- a/fs/ubifs/xattr.c +++ b/fs/ubifs/xattr.c @@ -406,7 +406,8 @@ static bool xattr_visible(const char *name) /* Show trusted namespace only for "power" users */ if (strncmp(name, XATTR_TRUSTED_PREFIX, - XATTR_TRUSTED_PREFIX_LEN) == 0 && !capable(CAP_SYS_ADMIN)) + XATTR_TRUSTED_PREFIX_LEN) == 0 && + !capable(CAP_SYS_ADMIN) && !capable(CAP_TRUSTED)) return false; return true; diff --git a/fs/xattr.c b/fs/xattr.c index 61cd28ba25f3..d9e9a0083dbb 100644 --- a/fs/xattr.c +++ b/fs/xattr.c @@ -113,7 +113,7 @@ xattr_permission(struct inode *inode, const char *name, int mask) * The trusted.* namespace can only be accessed by privileged users. */ if (!strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN)) { - if (!capable(CAP_SYS_ADMIN)) + if (!capable(CAP_SYS_ADMIN) && !capable(CAP_TRUSTED)) return (mask & MAY_WRITE) ? -EPERM : -ENODATA; return 0; } @@ -945,7 +945,7 @@ static int xattr_list_one(char **buffer, ssize_t *remaining_size, ssize_t simple_xattr_list(struct inode *inode, struct simple_xattrs *xattrs, char *buffer, size_t size) { - bool trusted = capable(CAP_SYS_ADMIN); + bool trusted = capable(CAP_SYS_ADMIN) || capable(CAP_TRUSTED); struct simple_xattr *xattr; ssize_t remaining_size = size; int err = 0;