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-rw-r--r--fs/afs/mntpt.c2
-rw-r--r--fs/autofs4/waitq.c4
-rw-r--r--fs/cifs/cifs_dfs_ref.c7
-rw-r--r--fs/debugfs/inode.c8
-rw-r--r--fs/exec.c10
-rw-r--r--fs/mount.h1
-rw-r--r--fs/namei.c9
-rw-r--r--fs/namespace.c127
-rw-r--r--fs/nfs/namespace.c2
-rw-r--r--fs/nfs/nfs4namespace.c2
-rw-r--r--fs/notify/inotify/inotify.h17
-rw-r--r--fs/notify/inotify/inotify_fsnotify.c6
-rw-r--r--fs/notify/inotify/inotify_user.c34
-rw-r--r--fs/nsfs.c13
-rw-r--r--fs/pnode.c61
-rw-r--r--fs/pnode.h2
-rw-r--r--fs/proc/base.c102
-rw-r--r--fs/proc/fd.c12
-rw-r--r--fs/proc/inode.c3
-rw-r--r--fs/proc/internal.h23
-rw-r--r--fs/proc/proc_sysctl.c66
-rw-r--r--fs/super.c13
22 files changed, 325 insertions, 199 deletions
diff --git a/fs/afs/mntpt.c b/fs/afs/mntpt.c
index 81dd075..d4fb0af 100644
--- a/fs/afs/mntpt.c
+++ b/fs/afs/mntpt.c
@@ -202,7 +202,7 @@ static struct vfsmount *afs_mntpt_do_automount(struct dentry *mntpt)
/* try and do the mount */
_debug("--- attempting mount %s -o %s ---", devname, options);
- mnt = vfs_kern_mount(&afs_fs_type, 0, devname, options);
+ mnt = vfs_submount(mntpt, &afs_fs_type, devname, options);
_debug("--- mount result %p ---", mnt);
free_page((unsigned long) devname);
diff --git a/fs/autofs4/waitq.c b/fs/autofs4/waitq.c
index 1278335..79fbd85 100644
--- a/fs/autofs4/waitq.c
+++ b/fs/autofs4/waitq.c
@@ -436,8 +436,8 @@ int autofs4_wait(struct autofs_sb_info *sbi,
memcpy(&wq->name, &qstr, sizeof(struct qstr));
wq->dev = autofs4_get_dev(sbi);
wq->ino = autofs4_get_ino(sbi);
- wq->uid = current_real_cred()->uid;
- wq->gid = current_real_cred()->gid;
+ wq->uid = current_cred()->uid;
+ wq->gid = current_cred()->gid;
wq->pid = pid;
wq->tgid = tgid;
wq->status = -EINTR; /* Status return if interrupted */
diff --git a/fs/cifs/cifs_dfs_ref.c b/fs/cifs/cifs_dfs_ref.c
index ec9dbbc..9156be5 100644
--- a/fs/cifs/cifs_dfs_ref.c
+++ b/fs/cifs/cifs_dfs_ref.c
@@ -245,7 +245,8 @@ compose_mount_options_err:
* @fullpath: full path in UNC format
* @ref: server's referral
*/
-static struct vfsmount *cifs_dfs_do_refmount(struct cifs_sb_info *cifs_sb,
+static struct vfsmount *cifs_dfs_do_refmount(struct dentry *mntpt,
+ struct cifs_sb_info *cifs_sb,
const char *fullpath, const struct dfs_info3_param *ref)
{
struct vfsmount *mnt;
@@ -259,7 +260,7 @@ static struct vfsmount *cifs_dfs_do_refmount(struct cifs_sb_info *cifs_sb,
if (IS_ERR(mountdata))
return (struct vfsmount *)mountdata;
- mnt = vfs_kern_mount(&cifs_fs_type, 0, devname, mountdata);
+ mnt = vfs_submount(mntpt, &cifs_fs_type, devname, mountdata);
kfree(mountdata);
kfree(devname);
return mnt;
@@ -334,7 +335,7 @@ static struct vfsmount *cifs_dfs_do_automount(struct dentry *mntpt)
mnt = ERR_PTR(-EINVAL);
break;
}
- mnt = cifs_dfs_do_refmount(cifs_sb,
+ mnt = cifs_dfs_do_refmount(mntpt, cifs_sb,
full_path, referrals + i);
cifs_dbg(FYI, "%s: cifs_dfs_do_refmount:%s , mnt:%p\n",
__func__, referrals[i].node_name, mnt);
diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index 7fb1732..7fd4ec4 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -187,9 +187,9 @@ static const struct super_operations debugfs_super_operations = {
static struct vfsmount *debugfs_automount(struct path *path)
{
- struct vfsmount *(*f)(void *);
- f = (struct vfsmount *(*)(void *))path->dentry->d_fsdata;
- return f(d_inode(path->dentry)->i_private);
+ debugfs_automount_t f;
+ f = (debugfs_automount_t)path->dentry->d_fsdata;
+ return f(path->dentry, d_inode(path->dentry)->i_private);
}
static const struct dentry_operations debugfs_dops = {
@@ -540,7 +540,7 @@ EXPORT_SYMBOL_GPL(debugfs_create_dir);
*/
struct dentry *debugfs_create_automount(const char *name,
struct dentry *parent,
- struct vfsmount *(*f)(void *),
+ debugfs_automount_t f,
void *data)
{
struct dentry *dentry = start_creating(name, parent);
diff --git a/fs/exec.c b/fs/exec.c
index e579466..698a860 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1426,12 +1426,8 @@ static void check_unsafe_exec(struct linux_binprm *bprm)
struct task_struct *p = current, *t;
unsigned n_fs;
- if (p->ptrace) {
- if (ptracer_capable(p, current_user_ns()))
- bprm->unsafe |= LSM_UNSAFE_PTRACE_CAP;
- else
- bprm->unsafe |= LSM_UNSAFE_PTRACE;
- }
+ if (p->ptrace)
+ bprm->unsafe |= LSM_UNSAFE_PTRACE;
/*
* This isn't strictly necessary, but it makes it harder for LSMs to
@@ -1479,7 +1475,7 @@ static void bprm_fill_uid(struct linux_binprm *bprm)
if (task_no_new_privs(current))
return;
- inode = file_inode(bprm->file);
+ inode = bprm->file->f_path.dentry->d_inode;
mode = READ_ONCE(inode->i_mode);
if (!(mode & (S_ISUID|S_ISGID)))
return;
diff --git a/fs/mount.h b/fs/mount.h
index 2c856fc..2826543 100644
--- a/fs/mount.h
+++ b/fs/mount.h
@@ -89,7 +89,6 @@ static inline int is_mounted(struct vfsmount *mnt)
}
extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *);
-extern struct mount *__lookup_mnt_last(struct vfsmount *, struct dentry *);
extern int __legitimize_mnt(struct vfsmount *, unsigned);
extern bool legitimize_mnt(struct vfsmount *, unsigned);
diff --git a/fs/namei.c b/fs/namei.c
index ad74877..da689c9 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1100,7 +1100,6 @@ static int follow_automount(struct path *path, struct nameidata *nd,
bool *need_mntput)
{
struct vfsmount *mnt;
- const struct cred *old_cred;
int err;
if (!path->dentry->d_op || !path->dentry->d_op->d_automount)
@@ -1129,9 +1128,7 @@ static int follow_automount(struct path *path, struct nameidata *nd,
if (nd->total_link_count >= 40)
return -ELOOP;
- old_cred = override_creds(&init_cred);
mnt = path->dentry->d_op->d_automount(path);
- revert_creds(old_cred);
if (IS_ERR(mnt)) {
/*
* The filesystem is allowed to return -EISDIR here to indicate
@@ -2941,10 +2938,16 @@ static inline int open_to_namei_flags(int flag)
static int may_o_create(const struct path *dir, struct dentry *dentry, umode_t mode)
{
+ struct user_namespace *s_user_ns;
int error = security_path_mknod(dir, dentry, mode, 0);
if (error)
return error;
+ s_user_ns = dir->dentry->d_sb->s_user_ns;
+ if (!kuid_has_mapping(s_user_ns, current_fsuid()) ||
+ !kgid_has_mapping(s_user_ns, current_fsgid()))
+ return -EOVERFLOW;
+
error = inode_permission(dir->dentry->d_inode, MAY_WRITE | MAY_EXEC);
if (error)
return error;
diff --git a/fs/namespace.c b/fs/namespace.c
index 487ba30..8bfad42 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -637,28 +637,6 @@ struct mount *__lookup_mnt(struct vfsmount *mnt, struct dentry *dentry)
}
/*
- * find the last mount at @dentry on vfsmount @mnt.
- * mount_lock must be held.
- */
-struct mount *__lookup_mnt_last(struct vfsmount *mnt, struct dentry *dentry)
-{
- struct mount *p, *res = NULL;
- p = __lookup_mnt(mnt, dentry);
- if (!p)
- goto out;
- if (!(p->mnt.mnt_flags & MNT_UMOUNT))
- res = p;
- hlist_for_each_entry_continue(p, mnt_hash) {
- if (&p->mnt_parent->mnt != mnt || p->mnt_mountpoint != dentry)
- break;
- if (!(p->mnt.mnt_flags & MNT_UMOUNT))
- res = p;
- }
-out:
- return res;
-}
-
-/*
* lookup_mnt - Return the first child mount mounted at path
*
* "First" means first mounted chronologically. If you create the
@@ -878,6 +856,13 @@ void mnt_set_mountpoint(struct mount *mnt,
hlist_add_head(&child_mnt->mnt_mp_list, &mp->m_list);
}
+static void __attach_mnt(struct mount *mnt, struct mount *parent)
+{
+ hlist_add_head_rcu(&mnt->mnt_hash,
+ m_hash(&parent->mnt, mnt->mnt_mountpoint));
+ list_add_tail(&mnt->mnt_child, &parent->mnt_mounts);
+}
+
/*
* vfsmount lock must be held for write
*/
@@ -886,28 +871,45 @@ static void attach_mnt(struct mount *mnt,
struct mountpoint *mp)
{
mnt_set_mountpoint(parent, mp, mnt);
- hlist_add_head_rcu(&mnt->mnt_hash, m_hash(&parent->mnt, mp->m_dentry));
- list_add_tail(&mnt->mnt_child, &parent->mnt_mounts);
+ __attach_mnt(mnt, parent);
}
-static void attach_shadowed(struct mount *mnt,
- struct mount *parent,
- struct mount *shadows)
+void mnt_change_mountpoint(struct mount *parent, struct mountpoint *mp, struct mount *mnt)
{
- if (shadows) {
- hlist_add_behind_rcu(&mnt->mnt_hash, &shadows->mnt_hash);
- list_add(&mnt->mnt_child, &shadows->mnt_child);
- } else {
- hlist_add_head_rcu(&mnt->mnt_hash,
- m_hash(&parent->mnt, mnt->mnt_mountpoint));
- list_add_tail(&mnt->mnt_child, &parent->mnt_mounts);
- }
+ struct mountpoint *old_mp = mnt->mnt_mp;
+ struct dentry *old_mountpoint = mnt->mnt_mountpoint;
+ struct mount *old_parent = mnt->mnt_parent;
+
+ list_del_init(&mnt->mnt_child);
+ hlist_del_init(&mnt->mnt_mp_list);
+ hlist_del_init_rcu(&mnt->mnt_hash);
+
+ attach_mnt(mnt, parent, mp);
+
+ put_mountpoint(old_mp);
+
+ /*
+ * Safely avoid even the suggestion this code might sleep or
+ * lock the mount hash by taking advantage of the knowledge that
+ * mnt_change_mountpoint will not release the final reference
+ * to a mountpoint.
+ *
+ * During mounting, the mount passed in as the parent mount will
+ * continue to use the old mountpoint and during unmounting, the
+ * old mountpoint will continue to exist until namespace_unlock,
+ * which happens well after mnt_change_mountpoint.
+ */
+ spin_lock(&old_mountpoint->d_lock);
+ old_mountpoint->d_lockref.count--;
+ spin_unlock(&old_mountpoint->d_lock);
+
+ mnt_add_count(old_parent, -1);
}
/*
* vfsmount lock must be held for write
*/
-static void commit_tree(struct mount *mnt, struct mount *shadows)
+static void commit_tree(struct mount *mnt)
{
struct mount *parent = mnt->mnt_parent;
struct mount *m;
@@ -925,7 +927,7 @@ static void commit_tree(struct mount *mnt, struct mount *shadows)
n->mounts += n->pending_mounts;
n->pending_mounts = 0;
- attach_shadowed(mnt, parent, shadows);
+ __attach_mnt(mnt, parent);
touch_mnt_namespace(n);
}
@@ -989,6 +991,21 @@ vfs_kern_mount(struct file_system_type *type, int flags, const char *name, void
}
EXPORT_SYMBOL_GPL(vfs_kern_mount);
+struct vfsmount *
+vfs_submount(const struct dentry *mountpoint, struct file_system_type *type,
+ const char *name, void *data)
+{
+ /* Until it is worked out how to pass the user namespace
+ * through from the parent mount to the submount don't support
+ * unprivileged mounts with submounts.
+ */
+ if (mountpoint->d_sb->s_user_ns != &init_user_ns)
+ return ERR_PTR(-EPERM);
+
+ return vfs_kern_mount(type, MS_SUBMOUNT, name, data);
+}
+EXPORT_SYMBOL_GPL(vfs_submount);
+
static struct mount *clone_mnt(struct mount *old, struct dentry *root,
int flag)
{
@@ -1764,7 +1781,6 @@ struct mount *copy_tree(struct mount *mnt, struct dentry *dentry,
continue;
for (s = r; s; s = next_mnt(s, r)) {
- struct mount *t = NULL;
if (!(flag & CL_COPY_UNBINDABLE) &&
IS_MNT_UNBINDABLE(s)) {
s = skip_mnt_tree(s);
@@ -1786,14 +1802,7 @@ struct mount *copy_tree(struct mount *mnt, struct dentry *dentry,
goto out;
lock_mount_hash();
list_add_tail(&q->mnt_list, &res->mnt_list);
- mnt_set_mountpoint(parent, p->mnt_mp, q);
- if (!list_empty(&parent->mnt_mounts)) {
- t = list_last_entry(&parent->mnt_mounts,
- struct mount, mnt_child);
- if (t->mnt_mp != p->mnt_mp)
- t = NULL;
- }
- attach_shadowed(q, parent, t);
+ attach_mnt(q, parent, p->mnt_mp);
unlock_mount_hash();
}
}
@@ -1992,10 +2001,18 @@ static int attach_recursive_mnt(struct mount *source_mnt,
{
HLIST_HEAD(tree_list);
struct mnt_namespace *ns = dest_mnt->mnt_ns;
+ struct mountpoint *smp;
struct mount *child, *p;
struct hlist_node *n;
int err;
+ /* Preallocate a mountpoint in case the new mounts need
+ * to be tucked under other mounts.
+ */
+ smp = get_mountpoint(source_mnt->mnt.mnt_root);
+ if (IS_ERR(smp))
+ return PTR_ERR(smp);
+
/* Is there space to add these mounts to the mount namespace? */
if (!parent_path) {
err = count_mounts(ns, source_mnt);
@@ -2022,16 +2039,19 @@ static int attach_recursive_mnt(struct mount *source_mnt,
touch_mnt_namespace(source_mnt->mnt_ns);
} else {
mnt_set_mountpoint(dest_mnt, dest_mp, source_mnt);
- commit_tree(source_mnt, NULL);
+ commit_tree(source_mnt);
}
hlist_for_each_entry_safe(child, n, &tree_list, mnt_hash) {
struct mount *q;
hlist_del_init(&child->mnt_hash);
- q = __lookup_mnt_last(&child->mnt_parent->mnt,
- child->mnt_mountpoint);
- commit_tree(child, q);
+ q = __lookup_mnt(&child->mnt_parent->mnt,
+ child->mnt_mountpoint);
+ if (q)
+ mnt_change_mountpoint(child, smp, q);
+ commit_tree(child);
}
+ put_mountpoint(smp);
unlock_mount_hash();
return 0;
@@ -2046,6 +2066,11 @@ static int attach_recursive_mnt(struct mount *source_mnt,
cleanup_group_ids(source_mnt, NULL);
out:
ns->pending_mounts = 0;
+
+ read_seqlock_excl(&mount_lock);
+ put_mountpoint(smp);
+ read_sequnlock_excl(&mount_lock);
+
return err;
}
@@ -2794,7 +2819,7 @@ long do_mount(const char *dev_name, const char __user *dir_name,
flags &= ~(MS_NOSUID | MS_NOEXEC | MS_NODEV | MS_ACTIVE | MS_BORN |
MS_NOATIME | MS_NODIRATIME | MS_RELATIME| MS_KERNMOUNT |
- MS_STRICTATIME | MS_NOREMOTELOCK);
+ MS_STRICTATIME | MS_NOREMOTELOCK | MS_SUBMOUNT);
if (flags & MS_REMOUNT)
retval = do_remount(&path, flags & ~MS_REMOUNT, mnt_flags,
diff --git a/fs/nfs/namespace.c b/fs/nfs/namespace.c
index 5551e8e..e49d831 100644
--- a/fs/nfs/namespace.c
+++ b/fs/nfs/namespace.c
@@ -226,7 +226,7 @@ static struct vfsmount *nfs_do_clone_mount(struct nfs_server *server,
const char *devname,
struct nfs_clone_mount *mountdata)
{
- return vfs_kern_mount(&nfs_xdev_fs_type, 0, devname, mountdata);
+ return vfs_submount(mountdata->dentry, &nfs_xdev_fs_type, devname, mountdata);
}
/**
diff --git a/fs/nfs/nfs4namespace.c b/fs/nfs/nfs4namespace.c
index d211049..d8b040b 100644
--- a/fs/nfs/nfs4namespace.c
+++ b/fs/nfs/nfs4namespace.c
@@ -279,7 +279,7 @@ static struct vfsmount *try_location(struct nfs_clone_mount *mountdata,
mountdata->hostname,
mountdata->mnt_path);
- mnt = vfs_kern_mount(&nfs4_referral_fs_type, 0, page, mountdata);
+ mnt = vfs_submount(mountdata->dentry, &nfs4_referral_fs_type, page, mountdata);
if (!IS_ERR(mnt))
break;
}
diff --git a/fs/notify/inotify/inotify.h b/fs/notify/inotify/inotify.h
index a6f5907..7c461fd 100644
--- a/fs/notify/inotify/inotify.h
+++ b/fs/notify/inotify/inotify.h
@@ -30,3 +30,20 @@ extern int inotify_handle_event(struct fsnotify_group *group,
const unsigned char *file_name, u32 cookie);
extern const struct fsnotify_ops inotify_fsnotify_ops;
+
+#ifdef CONFIG_INOTIFY_USER
+static inline void dec_inotify_instances(struct ucounts *ucounts)
+{
+ dec_ucount(ucounts, UCOUNT_INOTIFY_INSTANCES);
+}
+
+static inline struct ucounts *inc_inotify_watches(struct ucounts *ucounts)
+{
+ return inc_ucount(ucounts->ns, ucounts->uid, UCOUNT_INOTIFY_WATCHES);
+}
+
+static inline void dec_inotify_watches(struct ucounts *ucounts)
+{
+ dec_ucount(ucounts, UCOUNT_INOTIFY_WATCHES);
+}
+#endif
diff --git a/fs/notify/inotify/inotify_fsnotify.c b/fs/notify/inotify/inotify_fsnotify.c
index 19e7ec1..f36c293 100644
--- a/fs/notify/inotify/inotify_fsnotify.c
+++ b/fs/notify/inotify/inotify_fsnotify.c
@@ -165,10 +165,8 @@ static void inotify_free_group_priv(struct fsnotify_group *group)
/* ideally the idr is empty and we won't hit the BUG in the callback */
idr_for_each(&group->inotify_data.idr, idr_callback, group);
idr_destroy(&group->inotify_data.idr);
- if (group->inotify_data.user) {
- atomic_dec(&group->inotify_data.user->inotify_devs);
- free_uid(group->inotify_data.user);
- }
+ if (group->inotify_data.ucounts)
+ dec_inotify_instances(group->inotify_data.ucounts);
}
static void inotify_free_event(struct fsnotify_event *fsn_event)
diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c
index 69d1ea3..1cf41c6 100644
--- a/fs/notify/inotify/inotify_user.c
+++ b/fs/notify/inotify/inotify_user.c
@@ -44,10 +44,8 @@
#include <asm/ioctls.h>
-/* these are configurable via /proc/sys/fs/inotify/ */
-static int inotify_max_user_instances __read_mostly;
+/* configurable via /proc/sys/fs/inotify/ */
static int inotify_max_queued_events __read_mostly;
-static int inotify_max_user_watches __read_mostly;
static struct kmem_cache *inotify_inode_mark_cachep __read_mostly;
@@ -60,7 +58,7 @@ static int zero;
struct ctl_table inotify_table[] = {
{
.procname = "max_user_instances",
- .data = &inotify_max_user_instances,
+ .data = &init_user_ns.ucount_max[UCOUNT_INOTIFY_INSTANCES],
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
@@ -68,7 +66,7 @@ struct ctl_table inotify_table[] = {
},
{
.procname = "max_user_watches",
- .data = &inotify_max_user_watches,
+ .data = &init_user_ns.ucount_max[UCOUNT_INOTIFY_WATCHES],
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
@@ -500,7 +498,7 @@ void inotify_ignored_and_remove_idr(struct fsnotify_mark *fsn_mark,
/* remove this mark from the idr */
inotify_remove_from_idr(group, i_mark);
- atomic_dec(&group->inotify_data.user->inotify_watches);
+ dec_inotify_watches(group->inotify_data.ucounts);
}
/* ding dong the mark is dead */
@@ -584,14 +582,17 @@ static int inotify_new_watch(struct fsnotify_group *group,
tmp_i_mark->fsn_mark.mask = mask;
tmp_i_mark->wd = -1;
- ret = -ENOSPC;
- if (atomic_read(&group->inotify_data.user->inotify_watches) >= inotify_max_user_watches)
- goto out_err;
-
ret = inotify_add_to_idr(idr, idr_lock, tmp_i_mark);
if (ret)
goto out_err;
+ /* increment the number of watches the user has */
+ if (!inc_inotify_watches(group->inotify_data.ucounts)) {
+ inotify_remove_from_idr(group, tmp_i_mark);
+ ret = -ENOSPC;
+ goto out_err;
+ }
+
/* we are on the idr, now get on the inode */
ret = fsnotify_add_mark_locked(&tmp_i_mark->fsn_mark, group, inode,
NULL, 0);
@@ -601,8 +602,6 @@ static int inotify_new_watch(struct fsnotify_group *group,
goto out_err;
}
- /* increment the number of watches the user has */
- atomic_inc(&group->inotify_data.user->inotify_watches);
/* return the watch descriptor for this new mark */
ret = tmp_i_mark->wd;
@@ -653,10 +652,11 @@ static struct fsnotify_group *inotify_new_group(unsigned int max_events)
spin_lock_init(&group->inotify_data.idr_lock);
idr_init(&group->inotify_data.idr);
- group->inotify_data.user = get_current_user();
+ group->inotify_data.ucounts = inc_ucount(current_user_ns(),
+ current_euid(),
+ UCOUNT_INOTIFY_INSTANCES);
- if (atomic_inc_return(&group->inotify_data.user->inotify_devs) >
- inotify_max_user_instances) {
+ if (!group->inotify_data.ucounts) {
fsnotify_destroy_group(group);
return ERR_PTR(-EMFILE);
}
@@ -819,8 +819,8 @@ static int __init inotify_user_setup(void)
inotify_inode_mark_cachep = KMEM_CACHE(inotify_inode_mark, SLAB_PANIC);
inotify_max_queued_events = 16384;
- inotify_max_user_instances = 128;
- inotify_max_user_watches = 8192;
+ init_user_ns.ucount_max[UCOUNT_INOTIFY_INSTANCES] = 128;
+ init_user_ns.ucount_max[UCOUNT_INOTIFY_WATCHES] = 8192;
return 0;
}
diff --git a/fs/nsfs.c b/fs/nsfs.c
index 8c9fb29..1656843 100644
--- a/fs/nsfs.c
+++ b/fs/nsfs.c
@@ -7,6 +7,7 @@
#include <linux/seq_file.h>
#include <linux/user_namespace.h>
#include <linux/nsfs.h>
+#include <linux/uaccess.h>
static struct vfsmount *nsfs_mnt;
@@ -163,7 +164,10 @@ int open_related_ns(struct ns_common *ns,
static long ns_ioctl(struct file *filp, unsigned int ioctl,
unsigned long arg)
{
+ struct user_namespace *user_ns;
struct ns_common *ns = get_proc_ns(file_inode(filp));
+ uid_t __user *argp;
+ uid_t uid;
switch (ioctl) {
case NS_GET_USERNS:
@@ -172,6 +176,15 @@ static long ns_ioctl(struct file *filp, unsigned int ioctl,
if (!ns->ops->get_parent)
return -EINVAL;
return open_related_ns(ns, ns->ops->get_parent);
+ case NS_GET_NSTYPE:
+ return ns->ops->type;
+ case NS_GET_OWNER_UID:
+ if (ns->ops->type != CLONE_NEWUSER)
+ return -EINVAL;
+ user_ns = container_of(ns, struct user_namespace, ns);
+ argp = (uid_t __user *) arg;
+ uid = from_kuid_munged(current_user_ns(), user_ns->owner);
+ return put_user(uid, argp);
default:
return -ENOTTY;
}
diff --git a/fs/pnode.c b/fs/pnode.c
index 06a793f..5bc7896 100644
--- a/fs/pnode.c
+++ b/fs/pnode.c
@@ -322,6 +322,21 @@ out:
return ret;
}
+static struct mount *find_topper(struct mount *mnt)
+{
+ /* If there is exactly one mount covering mnt completely return it. */
+ struct mount *child;
+
+ if (!list_is_singular(&mnt->mnt_mounts))
+ return NULL;
+
+ child = list_first_entry(&mnt->mnt_mounts, struct mount, mnt_child);
+ if (child->mnt_mountpoint != mnt->mnt.mnt_root)
+ return NULL;
+
+ return child;
+}
+
/*
* return true if the refcount is greater than count
*/
@@ -342,9 +357,8 @@ static inline int do_refcount_check(struct mount *mnt, int count)
*/
int propagate_mount_busy(struct mount *mnt, int refcnt)
{
- struct mount *m, *child;
+ struct mount *m, *child, *topper;
struct mount *parent = mnt->mnt_parent;
- int ret = 0;
if (mnt == parent)
return do_refcount_check(mnt, refcnt);
@@ -359,12 +373,24 @@ int propagate_mount_busy(struct mount *mnt, int refcnt)
for (m = propagation_next(parent, parent); m;
m = propagation_next(m, parent)) {
- child = __lookup_mnt_last(&m->mnt, mnt->mnt_mountpoint);
- if (child && list_empty(&child->mnt_mounts) &&
- (ret = do_refcount_check(child, 1)))
- break;
+ int count = 1;
+ child = __lookup_mnt(&m->mnt, mnt->mnt_mountpoint);
+ if (!child)
+ continue;
+
+ /* Is there exactly one mount on the child that covers
+ * it completely whose reference should be ignored?
+ */
+ topper = find_topper(child);
+ if (topper)
+ count += 1;
+ else if (!list_empty(&child->mnt_mounts))
+ continue;
+
+ if (do_refcount_check(child, count))
+ return 1;
}
- return ret;
+ return 0;
}
/*
@@ -381,7 +407,7 @@ void propagate_mount_unlock(struct mount *mnt)
for (m = propagation_next(parent, parent); m;
m = propagation_next(m, parent)) {
- child = __lookup_mnt_last(&m->mnt, mnt->mnt_mountpoint);
+ child = __lookup_mnt(&m->mnt, mnt->mnt_mountpoint);
if (child)
child->mnt.mnt_flags &= ~MNT_LOCKED;
}
@@ -399,9 +425,11 @@ static void mark_umount_candidates(struct mount *mnt)
for (m = propagation_next(parent, parent); m;
m = propagation_next(m, parent)) {
- struct mount *child = __lookup_mnt_last(&m->mnt,
+ struct mount *child = __lookup_mnt(&m->mnt,
mnt->mnt_mountpoint);
- if (child && (!IS_MNT_LOCKED(child) || IS_MNT_MARKED(m))) {
+ if (!child || (child->mnt.mnt_flags & MNT_UMOUNT))
+ continue;
+ if (!IS_MNT_LOCKED(child) || IS_MNT_MARKED(m)) {
SET_MNT_MARK(child);
}
}
@@ -420,8 +448,8 @@ static void __propagate_umount(struct mount *mnt)
for (m = propagation_next(parent, parent); m;
m = propagation_next(m, parent)) {
-
- struct mount *child = __lookup_mnt_last(&m->mnt,
+ struct mount *topper;
+ struct mount *child = __lookup_mnt(&m->mnt,
mnt->mnt_mountpoint);
/*
* umount the child only if the child has no children
@@ -430,6 +458,15 @@ static void __propagate_umount(struct mount *mnt)
if (!child || !IS_MNT_MARKED(child))
continue;
CLEAR_MNT_MARK(child);
+
+ /* If there is exactly one mount covering all of child
+ * replace child with that mount.
+ */
+ topper = find_topper(child);
+ if (topper)
+ mnt_change_mountpoint(child->mnt_parent, child->mnt_mp,
+ topper);
+
if (list_empty(&child->mnt_mounts)) {
list_del_init(&child->mnt_child);
child->mnt.mnt_flags |= MNT_UMOUNT;
diff --git a/fs/pnode.h b/fs/pnode.h
index 550f5a8..dc87e65 100644
--- a/fs/pnode.h
+++ b/fs/pnode.h
@@ -49,6 +49,8 @@ int get_dominating_id(struct mount *mnt, const struct path *root);
unsigned int mnt_get_count(struct mount *mnt);
void mnt_set_mountpoint(struct mount *, struct mountpoint *,
struct mount *);
+void mnt_change_mountpoint(struct mount *parent, struct mountpoint *mp,
+ struct mount *mnt);
struct mount *copy_tree(struct mount *, struct dentry *, int);
bool is_path_reachable(struct mount *, struct dentry *,
const struct path *root);
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 3d773eb..b73b4de 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1667,12 +1667,63 @@ const struct inode_operations proc_pid_link_inode_operations = {
/* building an inode */
+void task_dump_owner(struct task_struct *task, mode_t mode,
+ kuid_t *ruid, kgid_t *rgid)
+{
+ /* Depending on the state of dumpable compute who should own a
+ * proc file for a task.
+ */
+ const struct cred *cred;
+ kuid_t uid;
+ kgid_t gid;
+
+ /* Default to the tasks effective ownership */
+ rcu_read_lock();
+ cred = __task_cred(task);
+ uid = cred->euid;
+ gid = cred->egid;
+ rcu_read_unlock();
+
+ /*
+ * Before the /proc/pid/status file was created the only way to read
+ * the effective uid of a /process was to stat /proc/pid. Reading
+ * /proc/pid/status is slow enough that procps and other packages
+ * kept stating /proc/pid. To keep the rules in /proc simple I have
+ * made this apply to all per process world readable and executable
+ * directories.
+ */
+ if (mode != (S_IFDIR|S_IRUGO|S_IXUGO)) {
+ struct mm_struct *mm;
+ task_lock(task);
+ mm = task->mm;
+ /* Make non-dumpable tasks owned by some root */
+ if (mm) {
+ if (get_dumpable(mm) != SUID_DUMP_USER) {
+ struct user_namespace *user_ns = mm->user_ns;
+
+ uid = make_kuid(user_ns, 0);
+ if (!uid_valid(uid))
+ uid = GLOBAL_ROOT_UID;
+
+ gid = make_kgid(user_ns, 0);
+ if (!gid_valid(gid))
+ gid = GLOBAL_ROOT_GID;
+ }
+ } else {
+ uid = GLOBAL_ROOT_UID;
+ gid = GLOBAL_ROOT_GID;
+ }
+ task_unlock(task);
+ }
+ *ruid = uid;
+ *rgid = gid;
+}
+
struct inode *proc_pid_make_inode(struct super_block * sb,
struct task_struct *task, umode_t mode)
{
struct inode * inode;
struct proc_inode *ei;
- const struct cred *cred;
/* We need a new inode */
@@ -1694,13 +1745,7 @@ struct inode *proc_pid_make_inode(struct super_block * sb,
if (!ei->pid)
goto out_unlock;
- if (task_dumpable(task)) {
- rcu_read_lock();
- cred = __task_cred(task);
- inode->i_uid = cred->euid;
- inode->i_gid = cred->egid;
- rcu_read_unlock();
- }
+ task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
security_task_to_inode(task, inode);
out:
@@ -1715,7 +1760,6 @@ int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
{
struct inode *inode = d_inode(dentry);
struct task_struct *task;
- const struct cred *cred;
struct pid_namespace *pid = dentry->d_sb->s_fs_info;
generic_fillattr(inode, stat);
@@ -1733,12 +1777,7 @@ int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
*/
return -ENOENT;
}
- if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
- task_dumpable(task)) {
- cred = __task_cred(task);
- stat->uid = cred->euid;
- stat->gid = cred->egid;
- }
+ task_dump_owner(task, inode->i_mode, &stat->uid, &stat->gid);
}
rcu_read_unlock();
return 0;
@@ -1754,18 +1793,11 @@ int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
* Rewrite the inode's ownerships here because the owning task may have
* performed a setuid(), etc.
*
- * Before the /proc/pid/status file was created the only way to read
- * the effective uid of a /process was to stat /proc/pid. Reading
- * /proc/pid/status is slow enough that procps and other packages
- * kept stating /proc/pid. To keep the rules in /proc simple I have
- * made this apply to all per process world readable and executable
- * directories.
*/
int pid_revalidate(struct dentry *dentry, unsigned int flags)
{
struct inode *inode;
struct task_struct *task;
- const struct cred *cred;
if (flags & LOOKUP_RCU)
return -ECHILD;
@@ -1774,17 +1806,8 @@ int pid_revalidate(struct dentry *dentry, unsigned int flags)
task = get_proc_task(inode);
if (task) {
- if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
- task_dumpable(task)) {
- rcu_read_lock();
- cred = __task_cred(task);
- inode->i_uid = cred->euid;
- inode->i_gid = cred->egid;
- rcu_read_unlock();
- } else {
- inode->i_uid = GLOBAL_ROOT_UID;
- inode->i_gid = GLOBAL_ROOT_GID;
- }
+ task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid);
+
inode->i_mode &= ~(S_ISUID | S_ISGID);
security_task_to_inode(task, inode);
put_task_struct(task);
@@ -1881,7 +1904,6 @@ static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
bool exact_vma_exists = false;
struct mm_struct *mm = NULL;
struct task_struct *task;
- const struct cred *cred;
struct inode *inode;
int status = 0;
@@ -1906,16 +1928,8 @@ static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
mmput(mm);
if (exact_vma_exists) {
- if (task_dumpable(task)) {
- rcu_read_lock();
- cred = __task_cred(task);
- inode->i_uid = cred->euid;
- inode->i_gid = cred->egid;
- rcu_read_unlock();
- } else {
- inode->i_uid = GLOBAL_ROOT_UID;
- inode->i_gid = GLOBAL_ROOT_GID;
- }
+ task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
+
security_task_to_inode(task, inode);
status = 1;
}
diff --git a/fs/proc/fd.c b/fs/proc/fd.c
index 4274f83..00ce153 100644
--- a/fs/proc/fd.c
+++ b/fs/proc/fd.c
@@ -84,7 +84,6 @@ static int tid_fd_revalidate(struct dentry *dentry, unsigned int flags)
{
struct files_struct *files;
struct task_struct *task;
- const struct cred *cred;
struct inode *inode;
unsigned int fd;
@@ -108,16 +107,7 @@ static int tid_fd_revalidate(struct dentry *dentry, unsigned int flags)
rcu_read_unlock();
put_files_struct(files);
- if (task_dumpable(task)) {
- rcu_read_lock();
- cred = __task_cred(task);
- inode->i_uid = cred->euid;
- inode->i_gid = cred->egid;
- rcu_read_unlock();
- } else {
- inode->i_uid = GLOBAL_ROOT_UID;
- inode->i_gid = GLOBAL_ROOT_GID;
- }
+ task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
if (S_ISLNK(inode->i_mode)) {
unsigned i_mode = S_IFLNK;
diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index 842a5ff..7ad9ed7 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -43,10 +43,11 @@ static void proc_evict_inode(struct inode *inode)
de = PDE(inode);
if (de)
pde_put(de);
+
head = PROC_I(inode)->sysctl;
if (head) {
RCU_INIT_POINTER(PROC_I(inode)->sysctl, NULL);
- sysctl_head_put(head);
+ proc_sys_evict_inode(inode, head);
}
}
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index 2de5194..5d6960f 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -65,6 +65,7 @@ struct proc_inode {
struct proc_dir_entry *pde;
struct ctl_table_header *sysctl;
struct ctl_table *sysctl_entry;
+ struct list_head sysctl_inodes;
const struct proc_ns_operations *ns_ops;
struct inode vfs_inode;
};
@@ -97,20 +98,8 @@ static inline struct task_struct *get_proc_task(struct inode *inode)
return get_pid_task(proc_pid(inode), PIDTYPE_PID);
}
-static inline int task_dumpable(struct task_struct *task)
-{
- int dumpable = 0;
- struct mm_struct *mm;
-
- task_lock(task);
- mm = task->mm;
- if (mm)
- dumpable = get_dumpable(mm);
- task_unlock(task);
- if (dumpable == SUID_DUMP_USER)
- return 1;
- return 0;
-}
+void task_dump_owner(struct task_struct *task, mode_t mode,
+ kuid_t *ruid, kgid_t *rgid);
static inline unsigned name_to_int(const struct qstr *qstr)
{
@@ -249,10 +238,12 @@ extern void proc_thread_self_init(void);
*/
#ifdef CONFIG_PROC_SYSCTL
extern int proc_sys_init(void);
-extern void sysctl_head_put(struct ctl_table_header *);
+extern void proc_sys_evict_inode(struct inode *inode,
+ struct ctl_table_header *head);
#else
static inline void proc_sys_init(void) { }
-static inline void sysctl_head_put(struct ctl_table_header *head) { }
+static inline void proc_sys_evict_inode(struct inode *inode,
+ struct ctl_table_header *head) { }
#endif
/*
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index d4e37ac..3e64c65 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -190,6 +190,7 @@ static void init_header(struct ctl_table_header *head,
head->set = set;
head->parent = NULL;
head->node = node;
+ INIT_LIST_HEAD(&head->inodes);
if (node) {
struct ctl_table *entry;
for (entry = table; entry->procname; entry++, node++)
@@ -259,6 +260,27 @@ static void unuse_table(struct ctl_table_header *p)
complete(p->unregistering);
}
+/* called under sysctl_lock */
+static void proc_sys_prune_dcache(struct ctl_table_header *head)
+{
+ struct inode *inode, *prev = NULL;
+ struct proc_inode *ei;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(ei, &head->inodes, sysctl_inodes) {
+ inode = igrab(&ei->vfs_inode);
+ if (inode) {
+ rcu_read_unlock();
+ iput(prev);
+ prev = inode;
+ d_prune_aliases(inode);
+ rcu_read_lock();
+ }
+ }
+ rcu_read_unlock();
+ iput(prev);
+}
+
/* called under sysctl_lock, will reacquire if has to wait */
static void start_unregistering(struct ctl_table_header *p)
{
@@ -272,31 +294,22 @@ static void start_unregistering(struct ctl_table_header *p)
p->unregistering = &wait;
spin_unlock(&sysctl_lock);
wait_for_completion(&wait);
- spin_lock(&sysctl_lock);
} else {
/* anything non-NULL; we'll never dereference it */
p->unregistering = ERR_PTR(-EINVAL);
+ spin_unlock(&sysctl_lock);
}
/*
+ * Prune dentries for unregistered sysctls: namespaced sysctls
+ * can have duplicate names and contaminate dcache very badly.
+ */
+ proc_sys_prune_dcache(p);
+ /*
* do not remove from the list until nobody holds it; walking the
* list in do_sysctl() relies on that.
*/
- erase_header(p);
-}
-
-static void sysctl_head_get(struct ctl_table_header *head)
-{
spin_lock(&sysctl_lock);
- head->count++;
- spin_unlock(&sysctl_lock);
-}
-
-void sysctl_head_put(struct ctl_table_header *head)
-{
- spin_lock(&sysctl_lock);
- if (!--head->count)
- kfree_rcu(head, rcu);
- spin_unlock(&sysctl_lock);
+ erase_header(p);
}
static struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
@@ -440,10 +453,20 @@ static struct inode *proc_sys_make_inode(struct super_block *sb,
inode->i_ino = get_next_ino();
- sysctl_head_get(head);
ei = PROC_I(inode);
+
+ spin_lock(&sysctl_lock);
+ if (unlikely(head->unregistering)) {
+ spin_unlock(&sysctl_lock);
+ iput(inode);
+ inode = NULL;
+ goto out;
+ }
ei->sysctl = head;
ei->sysctl_entry = table;
+ list_add_rcu(&ei->sysctl_inodes, &head->inodes);
+ head->count++;
+ spin_unlock(&sysctl_lock);
inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
inode->i_mode = table->mode;
@@ -466,6 +489,15 @@ out:
return inode;
}
+void proc_sys_evict_inode(struct inode *inode, struct ctl_table_header *head)
+{
+ spin_lock(&sysctl_lock);
+ list_del_rcu(&PROC_I(inode)->sysctl_inodes);
+ if (!--head->count)
+ kfree_rcu(head, rcu);
+ spin_unlock(&sysctl_lock);
+}
+
static struct ctl_table_header *grab_header(struct inode *inode)
{
struct ctl_table_header *head = PROC_I(inode)->sysctl;
diff --git a/fs/super.c b/fs/super.c
index ea662b0..b8b6a08 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -469,7 +469,7 @@ struct super_block *sget_userns(struct file_system_type *type,
struct super_block *old;
int err;
- if (!(flags & MS_KERNMOUNT) &&
+ if (!(flags & (MS_KERNMOUNT|MS_SUBMOUNT)) &&
!(type->fs_flags & FS_USERNS_MOUNT) &&
!capable(CAP_SYS_ADMIN))
return ERR_PTR(-EPERM);
@@ -499,7 +499,7 @@ retry:
}
if (!s) {
spin_unlock(&sb_lock);
- s = alloc_super(type, flags, user_ns);
+ s = alloc_super(type, (flags & ~MS_SUBMOUNT), user_ns);
if (!s)
return ERR_PTR(-ENOMEM);
goto retry;
@@ -540,8 +540,15 @@ struct super_block *sget(struct file_system_type *type,
{
struct user_namespace *user_ns = current_user_ns();
+ /* We don't yet pass the user namespace of the parent
+ * mount through to here so always use &init_user_ns
+ * until that changes.
+ */
+ if (flags & MS_SUBMOUNT)
+ user_ns = &init_user_ns;
+
/* Ensure the requestor has permissions over the target filesystem */
- if (!(flags & MS_KERNMOUNT) && !ns_capable(user_ns, CAP_SYS_ADMIN))
+ if (!(flags & (MS_KERNMOUNT|MS_SUBMOUNT)) && !ns_capable(user_ns, CAP_SYS_ADMIN))
return ERR_PTR(-EPERM);
return sget_userns(type, test, set, flags, user_ns, data);
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