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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

Browse Source 
Pull namespace changes from Eric Biederman:
 "This is an assorted mishmash of small cleanups, enhancements and bug
  fixes.

  The major theme is user namespace mount restrictions.  nsown_capable
  is killed as it encourages not thinking about details that need to be
  considered.  A very hard to hit pid namespace exiting bug was finally
  tracked and fixed.  A couple of cleanups to the basic namespace
  infrastructure.

  Finally there is an enhancement that makes per user namespace
  capabilities usable as capabilities, and an enhancement that allows
  the per userns root to nice other processes in the user namespace"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  userns:  Kill nsown_capable it makes the wrong thing easy
  capabilities: allow nice if we are privileged
  pidns: Don't have unshare(CLONE_NEWPID) imply CLONE_THREAD
  userns: Allow PR_CAPBSET_DROP in a user namespace.
  namespaces: Simplify copy_namespaces so it is clear what is going on.
  pidns: Fix hang in zap_pid_ns_processes by sending a potentially extra wakeup
  sysfs: Restrict mounting sysfs
  userns: Better restrictions on when proc and sysfs can be mounted
  vfs: Don't copy mount bind mounts of /proc/<pid>/ns/mnt between namespaces
  kernel/nsproxy.c: Improving a snippet of code.
  proc: Restrict mounting the proc filesystem
  vfs: Lock in place mounts from more privileged users
This commit is contained in:
Linus Torvalds
2013-09-07 14:35:32 -07:00
parent 11c7b03d42 c7b96acf14
commit c7c4591db6
27 changed files with 177 additions and 104 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
kernel/capability.c
View File

@@ -432,18 +432,6 @@ bool capable(int cap)
}
EXPORT_SYMBOL(capable);
/**
* nsown_capable - Check superior capability to one's own user_ns
* @cap: The capability in question
*
* Return true if the current task has the given superior capability
* targeted at its own user namespace.
*/
bool nsown_capable(int cap)
{
return ns_capable(current_user_ns(), cap);
}
/**
* inode_capable - Check superior capability over inode
* @inode: The inode in question

5
kernel/fork.c
View File

@@ -1824,11 +1824,6 @@ SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags)
*/
if (unshare_flags & CLONE_NEWUSER)
unshare_flags |= CLONE_THREAD | CLONE_FS;
/*
* If unsharing a pid namespace must also unshare the thread.
*/
if (unshare_flags & CLONE_NEWPID)
unshare_flags |= CLONE_THREAD;
/*
* If unsharing a thread from a thread group, must also unshare vm.
*/

2
kernel/groups.c
View File

@@ -233,7 +233,7 @@ SYSCALL_DEFINE2(setgroups, int, gidsetsize, gid_t __user *, grouplist)
struct group_info *group_info;
int retval;
if (!nsown_capable(CAP_SETGID))
if (!ns_capable(current_user_ns(), CAP_SETGID))
return -EPERM;
if ((unsigned)gidsetsize > NGROUPS_MAX)
return -EINVAL;

36
kernel/nsproxy.c
View File

@@ -126,22 +126,16 @@ int copy_namespaces(unsigned long flags, struct task_struct *tsk)
struct nsproxy *old_ns = tsk->nsproxy;
struct user_namespace *user_ns = task_cred_xxx(tsk, user_ns);
struct nsproxy *new_ns;
int err = 0;
if (!old_ns)
if (likely(!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
CLONE_NEWPID | CLONE_NEWNET)))) {
get_nsproxy(old_ns);
return 0;
get_nsproxy(old_ns);
if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
CLONE_NEWPID | CLONE_NEWNET)))
return 0;
if (!ns_capable(user_ns, CAP_SYS_ADMIN)) {
err = -EPERM;
goto out;
}
if (!ns_capable(user_ns, CAP_SYS_ADMIN))
return -EPERM;
/*
* CLONE_NEWIPC must detach from the undolist: after switching
* to a new ipc namespace, the semaphore arrays from the old
@@ -149,22 +143,16 @@ int copy_namespaces(unsigned long flags, struct task_struct *tsk)
* means share undolist with parent, so we must forbid using
* it along with CLONE_NEWIPC.
*/
if ((flags & CLONE_NEWIPC) && (flags & CLONE_SYSVSEM)) {
err = -EINVAL;
goto out;
}
if ((flags & (CLONE_NEWIPC | CLONE_SYSVSEM)) ==
(CLONE_NEWIPC | CLONE_SYSVSEM))
return -EINVAL;
new_ns = create_new_namespaces(flags, tsk, user_ns, tsk->fs);
if (IS_ERR(new_ns)) {
err = PTR_ERR(new_ns);
goto out;
}
if (IS_ERR(new_ns))
return PTR_ERR(new_ns);
tsk->nsproxy = new_ns;
out:
put_nsproxy(old_ns);
return err;
return 0;
}
void free_nsproxy(struct nsproxy *ns)

1
kernel/pid.c
View File

@@ -265,6 +265,7 @@ void free_pid(struct pid *pid)
struct pid_namespace *ns = upid->ns;
hlist_del_rcu(&upid->pid_chain);
switch(--ns->nr_hashed) {
case 2:
case 1:
/* When all that is left in the pid namespace
* is the reaper wake up the reaper. The reaper

2
kernel/pid_namespace.c
View File

@@ -329,7 +329,7 @@ static int pidns_install(struct nsproxy *nsproxy, void *ns)
struct pid_namespace *ancestor, *new = ns;
if (!ns_capable(new->user_ns, CAP_SYS_ADMIN) ||
!nsown_capable(CAP_SYS_ADMIN))
!ns_capable(current_user_ns(), CAP_SYS_ADMIN))
return -EPERM;
/*

20
kernel/sys.c
View File

@@ -337,7 +337,7 @@ SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid)
if (rgid != (gid_t) -1) {
if (gid_eq(old->gid, krgid) ||
gid_eq(old->egid, krgid) ||
nsown_capable(CAP_SETGID))
ns_capable(old->user_ns, CAP_SETGID))
new->gid = krgid;
else
goto error;
@@ -346,7 +346,7 @@ SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid)
if (gid_eq(old->gid, kegid) ||
gid_eq(old->egid, kegid) ||
gid_eq(old->sgid, kegid) ||
nsown_capable(CAP_SETGID))
ns_capable(old->user_ns, CAP_SETGID))
new->egid = kegid;
else
goto error;
@@ -387,7 +387,7 @@ SYSCALL_DEFINE1(setgid, gid_t, gid)
old = current_cred();
retval = -EPERM;
if (nsown_capable(CAP_SETGID))
if (ns_capable(old->user_ns, CAP_SETGID))
new->gid = new->egid = new->sgid = new->fsgid = kgid;
else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid))
new->egid = new->fsgid = kgid;
@@ -471,7 +471,7 @@ SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid)
new->uid = kruid;
if (!uid_eq(old->uid, kruid) &&
!uid_eq(old->euid, kruid) &&
!nsown_capable(CAP_SETUID))
!ns_capable(old->user_ns, CAP_SETUID))
goto error;
}
@@ -480,7 +480,7 @@ SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid)
if (!uid_eq(old->uid, keuid) &&
!uid_eq(old->euid, keuid) &&
!uid_eq(old->suid, keuid) &&
!nsown_capable(CAP_SETUID))
!ns_capable(old->user_ns, CAP_SETUID))
goto error;
}
@@ -534,7 +534,7 @@ SYSCALL_DEFINE1(setuid, uid_t, uid)
old = current_cred();
retval = -EPERM;
if (nsown_capable(CAP_SETUID)) {
if (ns_capable(old->user_ns, CAP_SETUID)) {
new->suid = new->uid = kuid;
if (!uid_eq(kuid, old->uid)) {
retval = set_user(new);
@@ -591,7 +591,7 @@ SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
old = current_cred();
retval = -EPERM;
if (!nsown_capable(CAP_SETUID)) {
if (!ns_capable(old->user_ns, CAP_SETUID)) {
if (ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) &&
!uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid))
goto error;
@@ -673,7 +673,7 @@ SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid)
old = current_cred();
retval = -EPERM;
if (!nsown_capable(CAP_SETGID)) {
if (!ns_capable(old->user_ns, CAP_SETGID)) {
if (rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) &&
!gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid))
goto error;
@@ -744,7 +744,7 @@ SYSCALL_DEFINE1(setfsuid, uid_t, uid)
if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) ||
uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) ||
nsown_capable(CAP_SETUID)) {
ns_capable(old->user_ns, CAP_SETUID)) {
if (!uid_eq(kuid, old->fsuid)) {
new->fsuid = kuid;
if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)
@@ -783,7 +783,7 @@ SYSCALL_DEFINE1(setfsgid, gid_t, gid)
if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) ||
gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) ||
nsown_capable(CAP_SETGID)) {
ns_capable(old->user_ns, CAP_SETGID)) {
if (!gid_eq(kgid, old->fsgid)) {
new->fsgid = kgid;
goto change_okay;

2
kernel/uid16.c
View File

@@ -176,7 +176,7 @@ SYSCALL_DEFINE2(setgroups16, int, gidsetsize, old_gid_t __user *, grouplist)
struct group_info *group_info;
int retval;
if (!nsown_capable(CAP_SETGID))
if (!ns_capable(current_user_ns(), CAP_SETGID))
return -EPERM;
if ((unsigned)gidsetsize > NGROUPS_MAX)
return -EINVAL;

2
kernel/user.c
View File

@@ -51,8 +51,6 @@ struct user_namespace init_user_ns = {
.owner = GLOBAL_ROOT_UID,
.group = GLOBAL_ROOT_GID,
.proc_inum = PROC_USER_INIT_INO,
.may_mount_sysfs = true,
.may_mount_proc = true,
};
EXPORT_SYMBOL_GPL(init_user_ns);

2
kernel/user_namespace.c
View File

@@ -101,8 +101,6 @@ int create_user_ns(struct cred *new)
set_cred_user_ns(new, ns);
update_mnt_policy(ns);
return 0;
}

2
kernel/utsname.c
View File

@@ -114,7 +114,7 @@ static int utsns_install(struct nsproxy *nsproxy, void *new)
struct uts_namespace *ns = new;
if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN) ||
!nsown_capable(CAP_SYS_ADMIN))
!ns_capable(current_user_ns(), CAP_SYS_ADMIN))
return -EPERM;
get_uts_ns(ns);