The patch titled
user ns: prepare copy_tree, copy_mnt, and their callers to handle errs
has been removed from the -mm tree. Its filename was
user-ns-prepare-copy_tree-copy_mnt-and-their-callers-to-handle-errs.patch
This patch was dropped because an updated version will be merged
------------------------------------------------------
Subject: user ns: prepare copy_tree, copy_mnt, and their callers to handle errs
With shareduserns and non-shareduserns mounts, it will be possible for
clone_mnt to return -EPERM if a namespace tries to bind mount a
non-shareduserns vfsmnt from another user namespace. But currently they only
return NULL, which is interpreted as -ENOMEM. Update the callers to handle
other errors.
Signed-off-by: Serge E. Hallyn <serue@xxxxxxxxxx>
Cc: Herbert Poetzl <herbert@xxxxxxxxxxxx>
Cc: Kirill Korotaev <dev@xxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
fs/namespace.c | 92 ++++++++++++++++++++++++-----------------------
fs/pnode.c | 5 +-
2 files changed, 51 insertions(+), 46 deletions(-)
diff -puN fs/namespace.c~user-ns-prepare-copy_tree-copy_mnt-and-their-callers-to-handle-errs fs/namespace.c
--- a/fs/namespace.c~user-ns-prepare-copy_tree-copy_mnt-and-their-callers-to-handle-errs
+++ a/fs/namespace.c
@@ -236,37 +236,39 @@ static struct vfsmount *clone_mnt(struct
struct super_block *sb = old->mnt_sb;
struct vfsmount *mnt = alloc_vfsmnt(old->mnt_devname);
- if (mnt) {
- mnt->mnt_flags = old->mnt_flags;
- atomic_inc(&sb->s_active);
- mnt->mnt_sb = sb;
- mnt->mnt_root = dget(root);
- mnt->mnt_mountpoint = mnt->mnt_root;
- mnt->mnt_parent = mnt;
-
- if (flag & CL_SLAVE) {
- list_add(&mnt->mnt_slave, &old->mnt_slave_list);
- mnt->mnt_master = old;
- CLEAR_MNT_SHARED(mnt);
- } else {
- if ((flag & CL_PROPAGATION) || IS_MNT_SHARED(old))
- list_add(&mnt->mnt_share, &old->mnt_share);
- if (IS_MNT_SLAVE(old))
- list_add(&mnt->mnt_slave, &old->mnt_slave);
- mnt->mnt_master = old->mnt_master;
- }
- if (flag & CL_MAKE_SHARED)
- set_mnt_shared(mnt);
+ if (!mnt)
+ return ERR_PTR(-ENOMEM);
- /* stick the duplicate mount on the same expiry list
- * as the original if that was on one */
- if (flag & CL_EXPIRE) {
- spin_lock(&vfsmount_lock);
- if (!list_empty(&old->mnt_expire))
- list_add(&mnt->mnt_expire, &old->mnt_expire);
- spin_unlock(&vfsmount_lock);
- }
+ mnt->mnt_flags = old->mnt_flags;
+ atomic_inc(&sb->s_active);
+ mnt->mnt_sb = sb;
+ mnt->mnt_root = dget(root);
+ mnt->mnt_mountpoint = mnt->mnt_root;
+ mnt->mnt_parent = mnt;
+
+ if (flag & CL_SLAVE) {
+ list_add(&mnt->mnt_slave, &old->mnt_slave_list);
+ mnt->mnt_master = old;
+ CLEAR_MNT_SHARED(mnt);
+ } else {
+ if ((flag & CL_PROPAGATION) || IS_MNT_SHARED(old))
+ list_add(&mnt->mnt_share, &old->mnt_share);
+ if (IS_MNT_SLAVE(old))
+ list_add(&mnt->mnt_slave, &old->mnt_slave);
+ mnt->mnt_master = old->mnt_master;
+ }
+ if (flag & CL_MAKE_SHARED)
+ set_mnt_shared(mnt);
+
+ /* stick the duplicate mount on the same expiry list
+ * as the original if that was on one */
+ if (flag & CL_EXPIRE) {
+ spin_lock(&vfsmount_lock);
+ if (!list_empty(&old->mnt_expire))
+ list_add(&mnt->mnt_expire, &old->mnt_expire);
+ spin_unlock(&vfsmount_lock);
}
+
return mnt;
}
@@ -703,13 +705,15 @@ struct vfsmount *copy_tree(struct vfsmou
{
struct vfsmount *res, *p, *q, *r, *s;
struct nameidata nd;
+ LIST_HEAD(umount_list);
if (!(flag & CL_COPY_ALL) && IS_MNT_UNBINDABLE(mnt))
return NULL;
res = q = clone_mnt(mnt, dentry, flag);
- if (!q)
- goto Enomem;
+ if (IS_ERR(q))
+ return q;
+
q->mnt_mountpoint = mnt->mnt_mountpoint;
p = mnt;
@@ -730,8 +734,8 @@ struct vfsmount *copy_tree(struct vfsmou
nd.mnt = q;
nd.dentry = p->mnt_mountpoint;
q = clone_mnt(p, p->mnt_root, flag);
- if (!q)
- goto Enomem;
+ if (IS_ERR(q))
+ goto Error;
spin_lock(&vfsmount_lock);
list_add_tail(&q->mnt_list, &res->mnt_list);
attach_mnt(q, &nd);
@@ -739,15 +743,13 @@ struct vfsmount *copy_tree(struct vfsmou
}
}
return res;
-Enomem:
- if (res) {
- LIST_HEAD(umount_list);
- spin_lock(&vfsmount_lock);
- umount_tree(res, 0, &umount_list);
- spin_unlock(&vfsmount_lock);
- release_mounts(&umount_list);
- }
- return NULL;
+Error:
+ spin_lock(&vfsmount_lock);
+ umount_tree(res, 0, &umount_list);
+ spin_unlock(&vfsmount_lock);
+ release_mounts(&umount_list);
+
+ return q;
}
/*
@@ -927,8 +929,10 @@ static int do_loopback(struct nameidata
else
mnt = clone_mnt(old_nd.mnt, old_nd.dentry, 0);
- if (!mnt)
+ if (!mnt || IS_ERR(mnt)) {
+ err = mnt ? PTR_ERR(mnt) : -ENOMEM;
goto out;
+ }
err = graft_tree(mnt, nd);
if (err) {
@@ -1465,7 +1469,7 @@ struct mnt_namespace *dup_mnt_ns(struct
/* First pass: copy the tree topology */
new_ns->root = copy_tree(mnt_ns->root, mnt_ns->root->mnt_root,
CL_COPY_ALL | CL_EXPIRE);
- if (!new_ns->root) {
+ if (!new_ns->root || IS_ERR(new_ns->root)) {
up_write(&namespace_sem);
kfree(new_ns);
return NULL;
diff -puN fs/pnode.c~user-ns-prepare-copy_tree-copy_mnt-and-their-callers-to-handle-errs fs/pnode.c
--- a/fs/pnode.c~user-ns-prepare-copy_tree-copy_mnt-and-their-callers-to-handle-errs
+++ a/fs/pnode.c
@@ -187,8 +187,9 @@ int propagate_mnt(struct vfsmount *dest_
source = get_source(m, prev_dest_mnt, prev_src_mnt, &type);
- if (!(child = copy_tree(source, source->mnt_root, type))) {
- ret = -ENOMEM;
+ child = copy_tree(source, source->mnt_root, type);
+ if (!child || IS_ERR(child)) {
+ ret = child ? PTR_ERR(child) : -ENOMEM;
list_splice(tree_list, tmp_list.prev);
goto out;
}
_
Patches currently in -mm which might be from serue@xxxxxxxxxx are
implement-file-posix-capabilities.patch
file-capabilities-dont-do-file-caps-if-mnt_nosuid.patch
file-capabilities-honor-secure_noroot.patch
user-ns-prepare-copy_tree-copy_mnt-and-their-callers-to-handle-errs.patch
user-ns-implement-shared-mounts.patch
user_ns-handle-file-sigio.patch
user-ns-implement-user-ns-unshare.patch
rename-attach_pid-to-find_attach_pid.patch
attach_pid-with-struct-pid-parameter.patch
remove-find_attach_pid.patch
statically-initialize-struct-pid-for-swapper.patch
explicitly-set-pgid-sid-of-init.patch
uts-namespace-remove-config_uts_ns.patch
integrity-service-api-and-dummy-provider-fix.patch
sysctl-move-utsname-sysctls-to-their-own-file.patch
sysctl-move-sysv-ipc-sysctls-to-their-own-file.patch
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