From patchwork Sun Nov 15 10:37:10 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Brauner X-Patchwork-Id: 11906197 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D780646DA for ; Sun, 15 Nov 2020 10:43:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BFB8A23A32 for ; Sun, 15 Nov 2020 10:43:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726958AbgKOKmv (ORCPT ); Sun, 15 Nov 2020 05:42:51 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:59370 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726826AbgKOKmu (ORCPT ); Sun, 15 Nov 2020 05:42:50 -0500 Received: from ip5f5af0a0.dynamic.kabel-deutschland.de ([95.90.240.160] helo=wittgenstein.fritz.box) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1keFRm-0000Kt-LI; Sun, 15 Nov 2020 10:39:50 +0000 From: Christian Brauner To: Alexander Viro , Christoph Hellwig , linux-fsdevel@vger.kernel.org Cc: John Johansen , James Morris , Mimi Zohar , Dmitry Kasatkin , Stephen Smalley , Casey Schaufler , Arnd Bergmann , Andreas Dilger , OGAWA Hirofumi , Geoffrey Thomas , Mrunal Patel , Josh Triplett , Andy Lutomirski , Theodore Tso , Alban Crequy , Tycho Andersen , David Howells , James Bottomley , Jann Horn , Seth Forshee , =?utf-8?q?St=C3=A9phane_Graber?= , Aleksa Sarai , Lennart Poettering , "Eric W. Biederman" , smbarber@chromium.org, Phil Estes , Serge Hallyn , Kees Cook , Todd Kjos , Jonathan Corbet , containers@lists.linux-foundation.org, linux-security-module@vger.kernel.org, linux-api@vger.kernel.org, linux-ext4@vger.kernel.org, linux-audit@redhat.com, linux-integrity@vger.kernel.org, selinux@vger.kernel.org, Christian Brauner Subject: [PATCH v2 31/39] audit: handle idmapped mounts Date: Sun, 15 Nov 2020 11:37:10 +0100 Message-Id: <20201115103718.298186-32-christian.brauner@ubuntu.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201115103718.298186-1-christian.brauner@ubuntu.com> References: <20201115103718.298186-1-christian.brauner@ubuntu.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: selinux@vger.kernel.org Audit will sometimes log the inode's i_uid and i_gid. Enable audit to log the mapped inode when it is accessed from an idmapped mount. Signed-off-by: Christian Brauner --- /* v2 */ unchanged --- fs/namei.c | 14 +++++++------- include/linux/audit.h | 10 ++++++---- ipc/mqueue.c | 8 ++++---- kernel/auditsc.c | 26 ++++++++++++++------------ 4 files changed, 31 insertions(+), 27 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 1d6a0da8bf81..976ee05c5027 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -986,7 +986,7 @@ static inline int may_follow_link(struct nameidata *nd, const struct inode *inod if (nd->flags & LOOKUP_RCU) return -ECHILD; - audit_inode(nd->name, nd->stack[0].link.dentry, 0); + audit_inode(nd->name, user_ns, nd->stack[0].link.dentry, 0); audit_log_path_denied(AUDIT_ANOM_LINK, "follow_link"); return -EACCES; } @@ -2398,7 +2398,7 @@ int filename_lookup(int dfd, struct filename *name, unsigned flags, retval = path_lookupat(&nd, flags | LOOKUP_REVAL, path); if (likely(!retval)) - audit_inode(name, path->dentry, + audit_inode(name, mnt_user_ns(path->mnt), path->dentry, flags & LOOKUP_MOUNTPOINT ? AUDIT_INODE_NOEVAL : 0); restore_nameidata(); putname(name); @@ -2440,7 +2440,7 @@ static struct filename *filename_parentat(int dfd, struct filename *name, if (likely(!retval)) { *last = nd.last; *type = nd.last_type; - audit_inode(name, parent->dentry, AUDIT_INODE_PARENT); + audit_inode(name, mnt_user_ns(parent->mnt), parent->dentry, AUDIT_INODE_PARENT); } else { putname(name); name = ERR_PTR(retval); @@ -3194,7 +3194,7 @@ static const char *open_last_lookups(struct nameidata *nd, if (unlikely(error)) return ERR_PTR(error); } - audit_inode(nd->name, dir, AUDIT_INODE_PARENT); + audit_inode(nd->name, mnt_user_ns(nd->path.mnt), dir, AUDIT_INODE_PARENT); /* trailing slashes? */ if (unlikely(nd->last.name[nd->last.len])) return ERR_PTR(-EISDIR); @@ -3260,7 +3260,7 @@ static int do_open(struct nameidata *nd, return error; } if (!(file->f_mode & FMODE_CREATED)) - audit_inode(nd->name, nd->path.dentry, 0); + audit_inode(nd->name, mnt_user_ns(nd->path.mnt), nd->path.dentry, 0); if (open_flag & O_CREAT) { if ((open_flag & O_EXCL) && !(file->f_mode & FMODE_CREATED)) return -EEXIST; @@ -3362,7 +3362,7 @@ static int do_tmpfile(struct nameidata *nd, unsigned flags, goto out2; dput(path.dentry); path.dentry = child; - audit_inode(nd->name, child, 0); + audit_inode(nd->name, user_ns, child, 0); /* Don't check for other permissions, the inode was just created */ error = may_open(&path, 0, op->open_flag); if (error) @@ -3381,7 +3381,7 @@ static int do_o_path(struct nameidata *nd, unsigned flags, struct file *file) struct path path; int error = path_lookupat(nd, flags, &path); if (!error) { - audit_inode(nd->name, path.dentry, 0); + audit_inode(nd->name, mnt_user_ns(path.mnt), path.dentry, 0); error = vfs_open(&path, file); path_put(&path); } diff --git a/include/linux/audit.h b/include/linux/audit.h index b3d859831a31..217d2b0c273e 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -293,8 +293,8 @@ extern void __audit_syscall_exit(int ret_success, long ret_value); extern struct filename *__audit_reusename(const __user char *uptr); extern void __audit_getname(struct filename *name); extern void __audit_getcwd(void); -extern void __audit_inode(struct filename *name, const struct dentry *dentry, - unsigned int flags); +extern void __audit_inode(struct filename *name, struct user_namespace *user_ns, + const struct dentry *dentry, unsigned int flags); extern void __audit_file(const struct file *); extern void __audit_inode_child(struct inode *parent, const struct dentry *dentry, @@ -357,10 +357,11 @@ static inline void audit_getcwd(void) __audit_getcwd(); } static inline void audit_inode(struct filename *name, + struct user_namespace *user_ns, const struct dentry *dentry, unsigned int aflags) { if (unlikely(!audit_dummy_context())) - __audit_inode(name, dentry, aflags); + __audit_inode(name, user_ns, dentry, aflags); } static inline void audit_file(struct file *file) { @@ -371,7 +372,7 @@ static inline void audit_inode_parent_hidden(struct filename *name, const struct dentry *dentry) { if (unlikely(!audit_dummy_context())) - __audit_inode(name, dentry, + __audit_inode(name, &init_user_ns, dentry, AUDIT_INODE_PARENT | AUDIT_INODE_HIDDEN); } static inline void audit_inode_child(struct inode *parent, @@ -587,6 +588,7 @@ static inline void audit_getname(struct filename *name) static inline void audit_getcwd(void) { } static inline void audit_inode(struct filename *name, + struct user_namespace *user_ns, const struct dentry *dentry, unsigned int aflags) { } diff --git a/ipc/mqueue.c b/ipc/mqueue.c index 5008e87b026d..f3943b2cc003 100644 --- a/ipc/mqueue.c +++ b/ipc/mqueue.c @@ -849,8 +849,8 @@ static void remove_notification(struct mqueue_inode_info *info) info->notify_user_ns = NULL; } -static int prepare_open(struct dentry *dentry, int oflag, int ro, - umode_t mode, struct filename *name, +static int prepare_open(struct user_namespace *user_ns, struct dentry *dentry, + int oflag, int ro, umode_t mode, struct filename *name, struct mq_attr *attr) { static const int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE, @@ -867,7 +867,7 @@ static int prepare_open(struct dentry *dentry, int oflag, int ro, mqueue_create_attr, attr); } /* it already existed */ - audit_inode(name, dentry, 0); + audit_inode(name, user_ns, dentry, 0); if ((oflag & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL)) return -EEXIST; if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY)) @@ -903,7 +903,7 @@ static int do_mq_open(const char __user *u_name, int oflag, umode_t mode, goto out_putfd; } path.mnt = mntget(mnt); - error = prepare_open(path.dentry, oflag, ro, mode, name, attr); + error = prepare_open(mnt_user_ns(path.mnt), path.dentry, oflag, ro, mode, name, attr); if (!error) { struct file *file = dentry_open(&path, oflag, current_cred()); if (!IS_ERR(file)) diff --git a/kernel/auditsc.c b/kernel/auditsc.c index ddb9213a3e81..348e6048f1b7 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -1936,6 +1936,7 @@ void __audit_getname(struct filename *name) } static inline int audit_copy_fcaps(struct audit_names *name, + struct user_namespace *user_ns, const struct dentry *dentry) { struct cpu_vfs_cap_data caps; @@ -1944,7 +1945,7 @@ static inline int audit_copy_fcaps(struct audit_names *name, if (!dentry) return 0; - rc = get_vfs_caps_from_disk(&init_user_ns, dentry, &caps); + rc = get_vfs_caps_from_disk(user_ns, dentry, &caps); if (rc) return rc; @@ -1960,21 +1961,22 @@ static inline int audit_copy_fcaps(struct audit_names *name, /* Copy inode data into an audit_names. */ static void audit_copy_inode(struct audit_names *name, - const struct dentry *dentry, - struct inode *inode, unsigned int flags) + struct user_namespace *user_ns, + const struct dentry *dentry, struct inode *inode, + unsigned int flags) { name->ino = inode->i_ino; name->dev = inode->i_sb->s_dev; name->mode = inode->i_mode; - name->uid = inode->i_uid; - name->gid = inode->i_gid; + name->uid = i_uid_into_mnt(user_ns, inode); + name->gid = i_gid_into_mnt(user_ns, inode); name->rdev = inode->i_rdev; security_inode_getsecid(inode, &name->osid); if (flags & AUDIT_INODE_NOEVAL) { name->fcap_ver = -1; return; } - audit_copy_fcaps(name, dentry); + audit_copy_fcaps(name, user_ns, dentry); } /** @@ -1983,8 +1985,8 @@ static void audit_copy_inode(struct audit_names *name, * @dentry: dentry being audited * @flags: attributes for this particular entry */ -void __audit_inode(struct filename *name, const struct dentry *dentry, - unsigned int flags) +void __audit_inode(struct filename *name, struct user_namespace *user_ns, + const struct dentry *dentry, unsigned int flags) { struct audit_context *context = audit_context(); struct inode *inode = d_backing_inode(dentry); @@ -2078,12 +2080,12 @@ void __audit_inode(struct filename *name, const struct dentry *dentry, n->type = AUDIT_TYPE_NORMAL; } handle_path(dentry); - audit_copy_inode(n, dentry, inode, flags & AUDIT_INODE_NOEVAL); + audit_copy_inode(n, user_ns, dentry, inode, flags & AUDIT_INODE_NOEVAL); } void __audit_file(const struct file *file) { - __audit_inode(NULL, file->f_path.dentry, 0); + __audit_inode(NULL, mnt_user_ns(file->f_path.mnt), file->f_path.dentry, 0); } /** @@ -2175,7 +2177,7 @@ void __audit_inode_child(struct inode *parent, n = audit_alloc_name(context, AUDIT_TYPE_PARENT); if (!n) return; - audit_copy_inode(n, NULL, parent, 0); + audit_copy_inode(n, &init_user_ns, NULL, parent, 0); } if (!found_child) { @@ -2194,7 +2196,7 @@ void __audit_inode_child(struct inode *parent, } if (inode) - audit_copy_inode(found_child, dentry, inode, 0); + audit_copy_inode(found_child, &init_user_ns, dentry, inode, 0); else found_child->ino = AUDIT_INO_UNSET; }