fix create_new_namespaces() return value
Cedric Le Goater [Mon, 16 Jul 2007 06:41:06 +0000 (23:41 -0700)]
dup_mnt_ns() and clone_uts_ns() return NULL on failure.  This is wrong,
create_new_namespaces() uses ERR_PTR() to catch an error.  This means that the
subsequent create_new_namespaces() will hit BUG_ON() in copy_mnt_ns() or
copy_utsname().

Modify create_new_namespaces() to also use the errors returned by the
copy_*_ns routines and not to systematically return ENOMEM.

[oleg@tv-sign.ru: better changelog]
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Cc: Serge E. Hallyn <serue@us.ibm.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/namespace.c
kernel/nsproxy.c
kernel/user_namespace.c
kernel/utsname.c

index c811a94..5585623 100644 (file)
@@ -1451,7 +1451,7 @@ static struct mnt_namespace *dup_mnt_ns(struct mnt_namespace *mnt_ns,
 
        new_ns = kmalloc(sizeof(struct mnt_namespace), GFP_KERNEL);
        if (!new_ns)
-               return NULL;
+               return ERR_PTR(-ENOMEM);
 
        atomic_set(&new_ns->count, 1);
        INIT_LIST_HEAD(&new_ns->list);
@@ -1465,7 +1465,7 @@ static struct mnt_namespace *dup_mnt_ns(struct mnt_namespace *mnt_ns,
        if (!new_ns->root) {
                up_write(&namespace_sem);
                kfree(new_ns);
-               return NULL;
+               return ERR_PTR(-ENOMEM);;
        }
        spin_lock(&vfsmount_lock);
        list_add_tail(&new_ns->list, &new_ns->root->mnt_list);
index 5aa28e2..15a6015 100644 (file)
@@ -58,30 +58,41 @@ static struct nsproxy *create_new_namespaces(int flags, struct task_struct *tsk,
                        struct fs_struct *new_fs)
 {
        struct nsproxy *new_nsp;
+       int err;
 
        new_nsp = clone_nsproxy(tsk->nsproxy);
        if (!new_nsp)
                return ERR_PTR(-ENOMEM);
 
        new_nsp->mnt_ns = copy_mnt_ns(flags, tsk->nsproxy->mnt_ns, new_fs);
-       if (IS_ERR(new_nsp->mnt_ns))
+       if (IS_ERR(new_nsp->mnt_ns)) {
+               err = PTR_ERR(new_nsp->mnt_ns);
                goto out_ns;
+       }
 
        new_nsp->uts_ns = copy_utsname(flags, tsk->nsproxy->uts_ns);
-       if (IS_ERR(new_nsp->uts_ns))
+       if (IS_ERR(new_nsp->uts_ns)) {
+               err = PTR_ERR(new_nsp->uts_ns);
                goto out_uts;
+       }
 
        new_nsp->ipc_ns = copy_ipcs(flags, tsk->nsproxy->ipc_ns);
-       if (IS_ERR(new_nsp->ipc_ns))
+       if (IS_ERR(new_nsp->ipc_ns)) {
+               err = PTR_ERR(new_nsp->ipc_ns);
                goto out_ipc;
+       }
 
        new_nsp->pid_ns = copy_pid_ns(flags, tsk->nsproxy->pid_ns);
-       if (IS_ERR(new_nsp->pid_ns))
+       if (IS_ERR(new_nsp->pid_ns)) {
+               err = PTR_ERR(new_nsp->pid_ns);
                goto out_pid;
+       }
 
        new_nsp->user_ns = copy_user_ns(flags, tsk->nsproxy->user_ns);
-       if (IS_ERR(new_nsp->user_ns))
+       if (IS_ERR(new_nsp->user_ns)) {
+               err = PTR_ERR(new_nsp->user_ns);
                goto out_user;
+       }
 
        return new_nsp;
 
@@ -99,7 +110,7 @@ out_uts:
                put_mnt_ns(new_nsp->mnt_ns);
 out_ns:
        kfree(new_nsp);
-       return ERR_PTR(-ENOMEM);
+       return ERR_PTR(err);
 }
 
 /*
index 89a27e8..d055d98 100644 (file)
@@ -34,7 +34,7 @@ static struct user_namespace *clone_user_ns(struct user_namespace *old_ns)
 
        ns = kmalloc(sizeof(struct user_namespace), GFP_KERNEL);
        if (!ns)
-               return NULL;
+               return ERR_PTR(-ENOMEM);
 
        kref_init(&ns->kref);
 
@@ -45,7 +45,7 @@ static struct user_namespace *clone_user_ns(struct user_namespace *old_ns)
        ns->root_user = alloc_uid(ns, 0);
        if (!ns->root_user) {
                kfree(ns);
-               return NULL;
+               return ERR_PTR(-ENOMEM);
        }
 
        /* Reset current->user with a new one */
@@ -53,7 +53,7 @@ static struct user_namespace *clone_user_ns(struct user_namespace *old_ns)
        if (!new_user) {
                free_uid(ns->root_user);
                kfree(ns);
-               return NULL;
+               return ERR_PTR(-ENOMEM);
        }
 
        switch_uid(new_user);
index 160c8c5..3ae4393 100644 (file)
@@ -13,6 +13,7 @@
 #include <linux/uts.h>
 #include <linux/utsname.h>
 #include <linux/version.h>
+#include <linux/err.h>
 
 /*
  * Clone a new ns copying an original utsname, setting refcount to 1
@@ -24,10 +25,11 @@ static struct uts_namespace *clone_uts_ns(struct uts_namespace *old_ns)
        struct uts_namespace *ns;
 
        ns = kmalloc(sizeof(struct uts_namespace), GFP_KERNEL);
-       if (ns) {
-               memcpy(&ns->name, &old_ns->name, sizeof(ns->name));
-               kref_init(&ns->kref);
-       }
+       if (!ns)
+               return ERR_PTR(-ENOMEM);
+
+       memcpy(&ns->name, &old_ns->name, sizeof(ns->name));
+       kref_init(&ns->kref);
        return ns;
 }