Pull idmapped mounts from Christian Brauner:
"This introduces idmapped mounts which has been in the making for some
time. Simply put, different mounts can expose the same file or
directory with different ownership. This initial implementation comes
with ports for fat, ext4 and with Christoph's port for xfs with more
filesystems being actively worked on by independent people and
maintainers.
Idmapping mounts handle a wide range of long standing use-cases. Here
are just a few:
- Idmapped mounts make it possible to easily share files between
multiple users or multiple machines especially in complex
scenarios. For example, idmapped mounts will be used in the
implementation of portable home directories in
systemd-homed.service(8) where they allow users to move their home
directory to an external storage device and use it on multiple
computers where they are assigned different uids and gids. This
effectively makes it possible to assign random uids and gids at
login time.
- It is possible to share files from the host with unprivileged
containers without having to change ownership permanently through
chown(2).
- It is possible to idmap a container's rootfs and without having to
mangle every file. For example, Chromebooks use it to share the
user's Download folder with their unprivileged containers in their
Linux subsystem.
- It is possible to share files between containers with
non-overlapping idmappings.
- Filesystem that lack a proper concept of ownership such as fat can
use idmapped mounts to implement discretionary access (DAC)
permission checking.
- They allow users to efficiently changing ownership on a per-mount
basis without having to (recursively) chown(2) all files. In
contrast to chown (2) changing ownership of large sets of files is
instantenous with idmapped mounts. This is especially useful when
ownership of a whole root filesystem of a virtual machine or
container is changed. With idmapped mounts a single syscall
mount_setattr syscall will be sufficient to change the ownership of
all files.
- Idmapped mounts always take the current ownership into account as
idmappings specify what a given uid or gid is supposed to be mapped
to. This contrasts with the chown(2) syscall which cannot by itself
take the current ownership of the files it changes into account. It
simply changes the ownership to the specified uid and gid. This is
especially problematic when recursively chown(2)ing a large set of
files which is commong with the aforementioned portable home
directory and container and vm scenario.
- Idmapped mounts allow to change ownership locally, restricting it
to specific mounts, and temporarily as the ownership changes only
apply as long as the mount exists.
Several userspace projects have either already put up patches and
pull-requests for this feature or will do so should you decide to pull
this:
- systemd: In a wide variety of scenarios but especially right away
in their implementation of portable home directories.
https://systemd.io/HOME_DIRECTORY/
- container runtimes: containerd, runC, LXD:To share data between
host and unprivileged containers, unprivileged and privileged
containers, etc. The pull request for idmapped mounts support in
containerd, the default Kubernetes runtime is already up for quite
a while now: https://github.com/containerd/containerd/pull/4734
- The virtio-fs developers and several users have expressed interest
in using this feature with virtual machines once virtio-fs is
ported.
- ChromeOS: Sharing host-directories with unprivileged containers.
I've tightly synced with all those projects and all of those listed
here have also expressed their need/desire for this feature on the
mailing list. For more info on how people use this there's a bunch of
talks about this too. Here's just two recent ones:
https://www.cncf.io/wp-content/uploads/2020/12/Rootless-Containers-in-Gitpod.pdf
https://fosdem.org/2021/schedule/event/containers_idmap/
This comes with an extensive xfstests suite covering both ext4 and
xfs:
https://git.kernel.org/brauner/xfstests-dev/h/idmapped_mounts
It covers truncation, creation, opening, xattrs, vfscaps, setid
execution, setgid inheritance and more both with idmapped and
non-idmapped mounts. It already helped to discover an unrelated xfs
setgid inheritance bug which has since been fixed in mainline. It will
be sent for inclusion with the xfstests project should you decide to
merge this.
In order to support per-mount idmappings vfsmounts are marked with
user namespaces. The idmapping of the user namespace will be used to
map the ids of vfs objects when they are accessed through that mount.
By default all vfsmounts are marked with the initial user namespace.
The initial user namespace is used to indicate that a mount is not
idmapped. All operations behave as before and this is verified in the
testsuite.
Based on prior discussions we want to attach the whole user namespace
and not just a dedicated idmapping struct. This allows us to reuse all
the helpers that already exist for dealing with idmappings instead of
introducing a whole new range of helpers. In addition, if we decide in
the future that we are confident enough to enable unprivileged users
to setup idmapped mounts the permission checking can take into account
whether the caller is privileged in the user namespace the mount is
currently marked with.
The user namespace the mount will be marked with can be specified by
passing a file descriptor refering to the user namespace as an
argument to the new mount_setattr() syscall together with the new
MOUNT_ATTR_IDMAP flag. The system call follows the openat2() pattern
of extensibility.
The following conditions must be met in order to create an idmapped
mount:
- The caller must currently have the CAP_SYS_ADMIN capability in the
user namespace the underlying filesystem has been mounted in.
- The underlying filesystem must support idmapped mounts.
- The mount must not already be idmapped. This also implies that the
idmapping of a mount cannot be altered once it has been idmapped.
- The mount must be a detached/anonymous mount, i.e. it must have
been created by calling open_tree() with the OPEN_TREE_CLONE flag
and it must not already have been visible in the filesystem.
The last two points guarantee easier semantics for userspace and the
kernel and make the implementation significantly simpler.
By default vfsmounts are marked with the initial user namespace and no
behavioral or performance changes are observed.
The manpage with a detailed description can be found here:
https://git.kernel.org/brauner/man-pages/c/
1d7b902e2875a1ff342e036a9f866a995640aea8
In order to support idmapped mounts, filesystems need to be changed
and mark themselves with the FS_ALLOW_IDMAP flag in fs_flags. The
patches to convert individual filesystem are not very large or
complicated overall as can be seen from the included fat, ext4, and
xfs ports. Patches for other filesystems are actively worked on and
will be sent out separately. The xfstestsuite can be used to verify
that port has been done correctly.
The mount_setattr() syscall is motivated independent of the idmapped
mounts patches and it's been around since July 2019. One of the most
valuable features of the new mount api is the ability to perform
mounts based on file descriptors only.
Together with the lookup restrictions available in the openat2()
RESOLVE_* flag namespace which we added in v5.6 this is the first time
we are close to hardened and race-free (e.g. symlinks) mounting and
path resolution.
While userspace has started porting to the new mount api to mount
proper filesystems and create new bind-mounts it is currently not
possible to change mount options of an already existing bind mount in
the new mount api since the mount_setattr() syscall is missing.
With the addition of the mount_setattr() syscall we remove this last
restriction and userspace can now fully port to the new mount api,
covering every use-case the old mount api could. We also add the
crucial ability to recursively change mount options for a whole mount
tree, both removing and adding mount options at the same time. This
syscall has been requested multiple times by various people and
projects.
There is a simple tool available at
https://github.com/brauner/mount-idmapped
that allows to create idmapped mounts so people can play with this
patch series. I'll add support for the regular mount binary should you
decide to pull this in the following weeks:
Here's an example to a simple idmapped mount of another user's home
directory:
u1001@f2-vm:/$ sudo ./mount --idmap both:1000:1001:1 /home/ubuntu/ /mnt
u1001@f2-vm:/$ ls -al /home/ubuntu/
total 28
drwxr-xr-x 2 ubuntu ubuntu 4096 Oct 28 22:07 .
drwxr-xr-x 4 root root 4096 Oct 28 04:00 ..
-rw------- 1 ubuntu ubuntu 3154 Oct 28 22:12 .bash_history
-rw-r--r-- 1 ubuntu ubuntu 220 Feb 25 2020 .bash_logout
-rw-r--r-- 1 ubuntu ubuntu 3771 Feb 25 2020 .bashrc
-rw-r--r-- 1 ubuntu ubuntu 807 Feb 25 2020 .profile
-rw-r--r-- 1 ubuntu ubuntu 0 Oct 16 16:11 .sudo_as_admin_successful
-rw------- 1 ubuntu ubuntu 1144 Oct 28 00:43 .viminfo
u1001@f2-vm:/$ ls -al /mnt/
total 28
drwxr-xr-x 2 u1001 u1001 4096 Oct 28 22:07 .
drwxr-xr-x 29 root root 4096 Oct 28 22:01 ..
-rw------- 1 u1001 u1001 3154 Oct 28 22:12 .bash_history
-rw-r--r-- 1 u1001 u1001 220 Feb 25 2020 .bash_logout
-rw-r--r-- 1 u1001 u1001 3771 Feb 25 2020 .bashrc
-rw-r--r-- 1 u1001 u1001 807 Feb 25 2020 .profile
-rw-r--r-- 1 u1001 u1001 0 Oct 16 16:11 .sudo_as_admin_successful
-rw------- 1 u1001 u1001 1144 Oct 28 00:43 .viminfo
u1001@f2-vm:/$ touch /mnt/my-file
u1001@f2-vm:/$ setfacl -m u:1001:rwx /mnt/my-file
u1001@f2-vm:/$ sudo setcap -n 1001 cap_net_raw+ep /mnt/my-file
u1001@f2-vm:/$ ls -al /mnt/my-file
-rw-rwxr--+ 1 u1001 u1001 0 Oct 28 22:14 /mnt/my-file
u1001@f2-vm:/$ ls -al /home/ubuntu/my-file
-rw-rwxr--+ 1 ubuntu ubuntu 0 Oct 28 22:14 /home/ubuntu/my-file
u1001@f2-vm:/$ getfacl /mnt/my-file
getfacl: Removing leading '/' from absolute path names
# file: mnt/my-file
# owner: u1001
# group: u1001
user::rw-
user:u1001:rwx
group::rw-
mask::rwx
other::r--
u1001@f2-vm:/$ getfacl /home/ubuntu/my-file
getfacl: Removing leading '/' from absolute path names
# file: home/ubuntu/my-file
# owner: ubuntu
# group: ubuntu
user::rw-
user:ubuntu:rwx
group::rw-
mask::rwx
other::r--"
* tag 'idmapped-mounts-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: (41 commits)
xfs: remove the possibly unused mp variable in xfs_file_compat_ioctl
xfs: support idmapped mounts
ext4: support idmapped mounts
fat: handle idmapped mounts
tests: add mount_setattr() selftests
fs: introduce MOUNT_ATTR_IDMAP
fs: add mount_setattr()
fs: add attr_flags_to_mnt_flags helper
fs: split out functions to hold writers
namespace: only take read lock in do_reconfigure_mnt()
mount: make {lock,unlock}_mount_hash() static
namespace: take lock_mount_hash() directly when changing flags
nfs: do not export idmapped mounts
overlayfs: do not mount on top of idmapped mounts
ecryptfs: do not mount on top of idmapped mounts
ima: handle idmapped mounts
apparmor: handle idmapped mounts
fs: make helpers idmap mount aware
exec: handle idmapped mounts
would_dump: handle idmapped mounts
...
rc = -EOPNOTSUPP;
goto out;
}
- rc = vfs_setxattr(&init_user_ns, lower_dentry, name, value, size,
- flags);
+ inode_lock(lower_inode);
- rc = __vfs_setxattr_locked(lower_dentry, name, value, size, flags, NULL);
++ rc = __vfs_setxattr_locked(&init_user_ns, lower_dentry, name, value, size, flags, NULL);
+ inode_unlock(lower_inode);
if (!rc && inode)
- fsstack_copy_attr_all(inode, d_inode(lower_dentry));
+ fsstack_copy_attr_all(inode, lower_inode);
out:
return rc;
}
return __f2fs_get_acl(inode, type, NULL);
}
- if (!in_group_p(inode->i_gid) &&
- !capable_wrt_inode_uidgid(inode, CAP_FSETID))
+static int f2fs_acl_update_mode(struct inode *inode, umode_t *mode_p,
+ struct posix_acl **acl)
+{
+ umode_t mode = inode->i_mode;
+ int error;
+
+ if (is_inode_flag_set(inode, FI_ACL_MODE))
+ mode = F2FS_I(inode)->i_acl_mode;
+
+ error = posix_acl_equiv_mode(*acl, &mode);
+ if (error < 0)
+ return error;
+ if (error == 0)
+ *acl = NULL;
++ if (!in_group_p(i_gid_into_mnt(&init_user_ns, inode)) &&
++ !capable_wrt_inode_uidgid(&init_user_ns, inode, CAP_FSETID))
+ mode &= ~S_ISGID;
+ *mode_p = mode;
+ return 0;
+}
+
static int __f2fs_set_acl(struct inode *inode, int type,
struct posix_acl *acl, struct page *ipage)
{
inode->i_ctime = attr->ia_ctime;
if (ia_valid & ATTR_MODE) {
umode_t mode = attr->ia_mode;
+ kgid_t kgid = i_gid_into_mnt(mnt_userns, inode);
- if (!in_group_p(inode->i_gid) &&
- !capable_wrt_inode_uidgid(inode, CAP_FSETID))
- if (!in_group_p(kgid) && !capable(CAP_FSETID))
++ if (!in_group_p(kgid) && !capable_wrt_inode_uidgid(mnt_userns, inode, CAP_FSETID))
mode &= ~S_ISGID;
set_acl_inode(inode, mode);
}
spin_unlock(&F2FS_I(inode)->i_size_lock);
}
- __setattr_copy(inode, attr);
+ __setattr_copy(&init_user_ns, inode, attr);
if (attr->ia_valid & ATTR_MODE) {
- err = posix_acl_chmod(inode, f2fs_get_inode_mode(inode));
- err = posix_acl_chmod(&init_user_ns, inode,
- f2fs_get_inode_mode(inode));
- if (err || is_inode_flag_set(inode, FI_ACL_MODE)) {
- inode->i_mode = F2FS_I(inode)->i_acl_mode;
++ err = posix_acl_chmod(&init_user_ns, inode, f2fs_get_inode_mode(inode));
+
+ if (is_inode_flag_set(inode, FI_ACL_MODE)) {
+ if (!err)
+ inode->i_mode = F2FS_I(inode)->i_acl_mode;
clear_inode_flag(inode, FI_ACL_MODE);
}
}
return res;
}
- static inline int may_lookup(struct nameidata *nd)
+ static inline int may_lookup(struct user_namespace *mnt_userns,
+ struct nameidata *nd)
{
if (nd->flags & LOOKUP_RCU) {
- int err = inode_permission(nd->inode, MAY_EXEC|MAY_NOT_BLOCK);
- int err = inode_permission(mnt_userns, nd->inode,
- MAY_EXEC | MAY_NOT_BLOCK);
- if (err != -ECHILD)
++ int err = inode_permission(mnt_userns, nd->inode, MAY_EXEC|MAY_NOT_BLOCK);
+ if (err != -ECHILD || !try_to_unlazy(nd))
return err;
- if (unlazy_walk(nd))
- return -ECHILD;
}
- return inode_permission(nd->inode, MAY_EXEC);
+ return inode_permission(mnt_userns, nd->inode, MAY_EXEC);
}
static int reserve_stack(struct nameidata *nd, struct path *link, unsigned seq)
path.dentry = child;
audit_inode(nd->name, child, 0);
/* Don't check for other permissions, the inode was just created */
- error = may_open(&path, 0, op->open_flag);
+ error = may_open(mnt_userns, &path, 0, op->open_flag);
- if (error)
- goto out2;
- file->f_path.mnt = path.mnt;
- error = finish_open(file, child, NULL);
+ if (!error)
+ error = vfs_open(&path, file);
out2:
mnt_drop_write(path.mnt);
out:
if (ovl_is_private_xattr(sb, name))
continue;
+
+ error = security_inode_copy_up_xattr(name);
+ if (error < 0 && error != -EOPNOTSUPP)
+ break;
+ if (error == 1) {
+ error = 0;
+ continue; /* Discard */
+ }
retry:
- size = vfs_getxattr(old, name, value, value_size);
+ size = vfs_getxattr(&init_user_ns, old, name, value, value_size);
if (size == -ERANGE)
- size = vfs_getxattr(old, name, NULL, 0);
+ size = vfs_getxattr(&init_user_ns, old, name, NULL, 0);
if (size < 0) {
error = size;
goto retry;
}
- error = vfs_setxattr(new, name, value, size, 0);
- error = security_inode_copy_up_xattr(name);
- if (error < 0 && error != -EOPNOTSUPP)
- break;
- if (error == 1) {
- error = 0;
- continue; /* Discard */
- }
+ error = vfs_setxattr(&init_user_ns, new, name, value, size, 0);
if (error) {
if (error != -EOPNOTSUPP || ovl_must_copy_xattr(name))
break;
goto out;
if (!value && !upperdentry) {
- err = vfs_getxattr(realdentry, name, NULL, 0);
+ old_cred = ovl_override_creds(dentry->d_sb);
+ err = vfs_getxattr(&init_user_ns, realdentry, name, NULL, 0);
+ revert_creds(old_cred);
if (err < 0)
goto out_drop_write;
}
inode->i_rdev = rdev;
ip->i_d.di_projid = prid;
- if (pip && XFS_INHERIT_GID(pip)) {
- inode->i_gid = VFS_I(pip)->i_gid;
- if ((VFS_I(pip)->i_mode & S_ISGID) && S_ISDIR(mode))
- inode->i_mode |= S_ISGID;
+ if (dir && !(dir->i_mode & S_ISGID) &&
+ (mp->m_flags & XFS_MOUNT_GRPID)) {
- inode->i_uid = current_fsuid();
++ inode->i_uid = fsuid_into_mnt(mnt_userns);
+ inode->i_gid = dir->i_gid;
+ inode->i_mode = mode;
} else {
- inode_init_owner(inode, dir, mode);
- inode->i_gid = fsgid_into_mnt(mnt_userns);
++ inode_init_owner(mnt_userns, inode, dir, mode);
}
/*
resblks = XFS_IALLOC_SPACE_RES(mp);
tres = &M_RES(mp)->tr_create_tmpfile;
- error = xfs_trans_alloc(mp, tres, resblks, 0, 0, &tp);
- if (error)
- goto out_release_inode;
-
- error = xfs_trans_reserve_quota(tp, mp, udqp, gdqp,
- pdqp, resblks, 1, 0);
+ error = xfs_trans_alloc_icreate(mp, tres, udqp, gdqp, pdqp, resblks,
+ &tp);
if (error)
- goto out_trans_cancel;
+ goto out_release_dquots;
- error = xfs_dir_ialloc(&tp, dp, mode, 0, 0, prid, &ip);
+ error = xfs_dir_ialloc(mnt_userns, &tp, dp, mode, 0, 0, prid, &ip);
if (error)
goto out_trans_cancel;
*/
static struct xfs_trans *
xfs_ioctl_setattr_get_trans(
- struct xfs_inode *ip,
- struct file *file)
++ struct file *file,
+ struct xfs_dquot *pdqp)
{
+ struct xfs_inode *ip = XFS_I(file_inode(file));
struct xfs_mount *mp = ip->i_mount;
struct xfs_trans *tp;
int error = -EROFS;
xfs_ioctl_setattr_prepare_dax(ip, fa);
- tp = xfs_ioctl_setattr_get_trans(ip, pdqp);
- tp = xfs_ioctl_setattr_get_trans(file);
++ tp = xfs_ioctl_setattr_get_trans(file, pdqp);
if (IS_ERR(tp)) {
- code = PTR_ERR(tp);
+ error = PTR_ERR(tp);
goto error_free_dquots;
}
xfs_ioctl_setattr_prepare_dax(ip, &fa);
- tp = xfs_ioctl_setattr_get_trans(ip, NULL);
- tp = xfs_ioctl_setattr_get_trans(filp);
++ tp = xfs_ioctl_setattr_get_trans(filp, NULL);
if (IS_ERR(tp)) {
error = PTR_ERR(tp);
goto out_drop_write;
fs_ns = inode->i_sb->s_user_ns;
cap = (struct vfs_cap_data *) tmpbuf;
if (is_v2header((size_t) ret, cap)) {
- /* If this is sizeof(vfs_cap_data) then we're ok with the
- * on-disk value, so return that. */
- if (alloc)
- *buffer = tmpbuf;
- else
- kfree(tmpbuf);
- return ret;
- } else if (!is_v3header((size_t) ret, cap)) {
- kfree(tmpbuf);
- return -EINVAL;
+ root = 0;
+ } else if (is_v3header((size_t) ret, cap)) {
+ nscap = (struct vfs_ns_cap_data *) tmpbuf;
+ root = le32_to_cpu(nscap->rootid);
+ } else {
+ size = -EINVAL;
+ goto out_free;
}
- nscap = (struct vfs_ns_cap_data *) tmpbuf;
- root = le32_to_cpu(nscap->rootid);
kroot = make_kuid(fs_ns, root);
+ /* If this is an idmapped mount shift the kuid. */
+ kroot = kuid_into_mnt(mnt_userns, kroot);
+
/* If the root kuid maps to a valid uid in current ns, then return
* this as a nscap. */
mappedroot = from_kuid(current_user_ns(), kroot);
#endif /* CONFIG_IMA_QUEUE_EARLY_BOOT_KEYS */
/* LIM API function definitions */
- int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid,
- int mask, enum ima_hooks func, int *pcr,
+ int ima_get_action(struct user_namespace *mnt_userns, struct inode *inode,
+ const struct cred *cred, u32 secid, int mask,
+ enum ima_hooks func, int *pcr,
struct ima_template_desc **template_desc,
- const char *keyring);
+ const char *func_data);
int ima_must_measure(struct inode *inode, int mask, enum ima_hooks func);
int ima_collect_measurement(struct integrity_iint_cache *iint,
struct file *file, void *buf, loff_t size,
struct evm_ima_xattr_data *xattr_value,
int xattr_len, const struct modsig *modsig, int pcr,
struct ima_template_desc *template_desc);
- void process_buffer_measurement(struct inode *inode, const void *buf, int size,
+ void process_buffer_measurement(struct user_namespace *mnt_userns,
+ struct inode *inode, const void *buf, int size,
const char *eventname, enum ima_hooks func,
- int pcr, const char *keyring);
+ int pcr, const char *func_data,
+ bool buf_hash);
void ima_audit_measurement(struct integrity_iint_cache *iint,
const unsigned char *filename);
int ima_alloc_init_template(struct ima_event_data *event_data,
const char *ima_d_path(const struct path *path, char **pathbuf, char *filename);
/* IMA policy related functions */
- int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
- enum ima_hooks func, int mask, int flags, int *pcr,
+ int ima_match_policy(struct user_namespace *mnt_userns, struct inode *inode,
+ const struct cred *cred, u32 secid, enum ima_hooks func,
+ int mask, int flags, int *pcr,
struct ima_template_desc **template_desc,
- const char *keyring);
+ const char *func_data);
void ima_init_policy(void);
void ima_update_policy(void);
void ima_update_policy_flag(void);
* Returns IMA_MEASURE, IMA_APPRAISE mask.
*
*/
- int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid,
- int mask, enum ima_hooks func, int *pcr,
+ int ima_get_action(struct user_namespace *mnt_userns, struct inode *inode,
+ const struct cred *cred, u32 secid, int mask,
+ enum ima_hooks func, int *pcr,
struct ima_template_desc **template_desc,
- const char *keyring)
+ const char *func_data)
{
int flags = IMA_MEASURE | IMA_AUDIT | IMA_APPRAISE | IMA_HASH;
flags &= ima_policy_flag;
- return ima_match_policy(inode, cred, secid, func, mask, flags, pcr,
- template_desc, func_data);
+ return ima_match_policy(mnt_userns, inode, cred, secid, func, mask,
- flags, pcr, template_desc, keyring);
++ flags, pcr, template_desc, func_data);
}
/*
rc = is_binary_blacklisted(digest, digestsize);
if ((rc == -EPERM) && (iint->flags & IMA_MEASURE))
- process_buffer_measurement(NULL, digest, digestsize,
+ process_buffer_measurement(&init_user_ns, NULL, digest, digestsize,
"blacklisted-hash", NONE,
- pcr, NULL);
+ pcr, NULL, false);
}
return rc;
* if the IMA policy is configured to measure a key linked
* to the given keyring.
*/
- process_buffer_measurement(NULL, payload, payload_len,
+ process_buffer_measurement(&init_user_ns, NULL, payload, payload_len,
keyring->description, KEY_CHECK, 0,
- keyring->description);
+ keyring->description, false);
}
}
/*
- * process_buffer_measurement - Measure the buffer to ima log.
+ * process_buffer_measurement - Measure the buffer or the buffer data hash
+ * @mnt_userns: user namespace of the mount the inode was found from
* @inode: inode associated with the object being measured (NULL for KEY_CHECK)
* @buf: pointer to the buffer that needs to be added to the log.
* @size: size of buffer(in bytes).
* @eventname: event name to be used for the buffer entry.
* @func: IMA hook
* @pcr: pcr to extend the measurement
- * @keyring: keyring name to determine the action to be performed
+ * @func_data: func specific data, may be NULL
+ * @buf_hash: measure buffer data hash
*
- * Based on policy, the buffer is measured into the ima log.
+ * Based on policy, either the buffer data or buffer data hash is measured
*/
- void process_buffer_measurement(struct inode *inode, const void *buf, int size,
+ void process_buffer_measurement(struct user_namespace *mnt_userns,
+ struct inode *inode, const void *buf, int size,
const char *eventname, enum ima_hooks func,
- int pcr, const char *keyring)
+ int pcr, const char *func_data,
+ bool buf_hash)
{
int ret = 0;
const char *audit_cause = "ENOMEM";
*/
if (func) {
security_task_getsecid(current, &secid);
- action = ima_get_action(inode, current_cred(), secid, 0, func,
- &pcr, &template, func_data);
+ action = ima_get_action(mnt_userns, inode, current_cred(),
+ secid, 0, func, &pcr, &template,
- keyring);
++ func_data);
if (!(action & IMA_MEASURE))
return;
}
if (!f.file)
return;
- process_buffer_measurement(file_inode(f.file), buf, size,
- "kexec-cmdline", KEXEC_CMDLINE, 0, NULL,
- false);
+ process_buffer_measurement(file_mnt_user_ns(f.file), file_inode(f.file),
+ buf, size, "kexec-cmdline", KEXEC_CMDLINE, 0,
- NULL);
++ NULL, false);
fdput(f);
}
- process_buffer_measurement(NULL, buf, buf_len, event_name,
+/**
+ * ima_measure_critical_data - measure kernel integrity critical data
+ * @event_label: unique event label for grouping and limiting critical data
+ * @event_name: event name for the record in the IMA measurement list
+ * @buf: pointer to buffer data
+ * @buf_len: length of buffer data (in bytes)
+ * @hash: measure buffer data hash
+ *
+ * Measure data critical to the integrity of the kernel into the IMA log
+ * and extend the pcr. Examples of critical data could be various data
+ * structures, policies, and states stored in kernel memory that can
+ * impact the integrity of the system.
+ */
+void ima_measure_critical_data(const char *event_label,
+ const char *event_name,
+ const void *buf, size_t buf_len,
+ bool hash)
+{
+ if (!event_name || !event_label || !buf || !buf_len)
+ return;
+
++ process_buffer_measurement(&init_user_ns, NULL, buf, buf_len, event_name,
+ CRITICAL_DATA, 0, event_label,
+ hash);
+}
+
static int __init init_ima(void)
{
int error;
*
* Returns true on rule match, false on failure.
*/
- static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
- const struct cred *cred, u32 secid,
- enum ima_hooks func, int mask,
+ static bool ima_match_rules(struct ima_rule_entry *rule,
+ struct user_namespace *mnt_userns,
+ struct inode *inode, const struct cred *cred,
+ u32 secid, enum ima_hooks func, int mask,
- const char *keyring)
+ const char *func_data)
{
int i;
* list when walking it. Reads are many orders of magnitude more numerous
* than writes so ima_match_policy() is classical RCU candidate.
*/
- int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
- enum ima_hooks func, int mask, int flags, int *pcr,
+ int ima_match_policy(struct user_namespace *mnt_userns, struct inode *inode,
+ const struct cred *cred, u32 secid, enum ima_hooks func,
+ int mask, int flags, int *pcr,
struct ima_template_desc **template_desc,
- const char *keyring)
+ const char *func_data)
{
struct ima_rule_entry *entry;
int action = 0, actmask = flags | (flags << 1);
if (!(entry->action & actmask))
continue;
- if (!ima_match_rules(entry, inode, cred, secid, func, mask,
- func_data))
+ if (!ima_match_rules(entry, mnt_userns, inode, cred, secid,
- func, mask, keyring))
++ func, mask, func_data))
continue;
action |= entry->flags & IMA_ACTION_FLAGS;
TARGETS += memory-hotplug
TARGETS += mincore
TARGETS += mount
+ TARGETS += mount_setattr
TARGETS += mqueue
+TARGETS += nci
TARGETS += net
TARGETS += net/forwarding
TARGETS += net/mptcp
projects / linux-2.6-microblaze.git / commitdiff