linux/kernel
Serge Hallyn 18b6e0414e User namespaces: set of cleanups (v2)
The user_ns is moved from nsproxy to user_struct, so that a struct
cred by itself is sufficient to determine access (which it otherwise
would not be).  Corresponding ecryptfs fixes (by David Howells) are
here as well.

Fix refcounting.  The following rules now apply:
        1. The task pins the user struct.
        2. The user struct pins its user namespace.
        3. The user namespace pins the struct user which created it.

User namespaces are cloned during copy_creds().  Unsharing a new user_ns
is no longer possible.  (We could re-add that, but it'll cause code
duplication and doesn't seem useful if PAM doesn't need to clone user
namespaces).

When a user namespace is created, its first user (uid 0) gets empty
keyrings and a clean group_info.

This incorporates a previous patch by David Howells.  Here
is his original patch description:

>I suggest adding the attached incremental patch.  It makes the following
>changes:
>
> (1) Provides a current_user_ns() macro to wrap accesses to current's user
>     namespace.
>
> (2) Fixes eCryptFS.
>
> (3) Renames create_new_userns() to create_user_ns() to be more consistent
>     with the other associated functions and because the 'new' in the name is
>     superfluous.
>
> (4) Moves the argument and permission checks made for CLONE_NEWUSER to the
>     beginning of do_fork() so that they're done prior to making any attempts
>     at allocation.
>
> (5) Calls create_user_ns() after prepare_creds(), and gives it the new creds
>     to fill in rather than have it return the new root user.  I don't imagine
>     the new root user being used for anything other than filling in a cred
>     struct.
>
>     This also permits me to get rid of a get_uid() and a free_uid(), as the
>     reference the creds were holding on the old user_struct can just be
>     transferred to the new namespace's creator pointer.
>
> (6) Makes create_user_ns() reset the UIDs and GIDs of the creds under
>     preparation rather than doing it in copy_creds().
>
>David

>Signed-off-by: David Howells <dhowells@redhat.com>

Changelog:
	Oct 20: integrate dhowells comments
		1. leave thread_keyring alone
		2. use current_user_ns() in set_user()

Signed-off-by: Serge Hallyn <serue@us.ibm.com>
2008-11-24 18:57:41 -05:00
..
irq irq: make variable static 2008-10-22 07:37:17 +02:00
power PM_TEST_SUSPEND should depend on RTC_CLASS, not RTC_LIB 2008-11-01 12:40:38 -07:00
time nohz: disable tick_nohz_kick_tick() for now 2008-11-10 22:39:27 +01:00
trace Merge branch 'master' into next 2008-11-14 11:29:12 +11:00
.gitignore
acct.c CRED: Wrap task credential accesses in the core kernel 2008-11-14 10:39:12 +11:00
audit_tree.c Fix inotify watch removal/umount races 2008-11-15 12:26:44 -08:00
audit.c [PATCH] Fix the bug of using AUDIT_STATUS_RATE_LIMIT when set fail, no error output. 2008-08-01 12:15:16 -04:00
audit.h
auditfilter.c Fix inotify watch removal/umount races 2008-11-15 12:26:44 -08:00
auditsc.c CRED: Inaugurate COW credentials 2008-11-14 10:39:23 +11:00
backtracetest.c backtrace: replace timer with tasklet + completions 2008-06-27 18:09:16 +02:00
bounds.c
capability.c CRED: Inaugurate COW credentials 2008-11-14 10:39:23 +11:00
cgroup_debug.c cgroups: fix probable race with put_css_set[_taskexit] and find_css_set 2008-10-20 08:52:38 -07:00
cgroup_freezer.c freezer_cg: disable writing freezer.state of root cgroup 2008-11-12 17:17:16 -08:00
cgroup.c Merge branch 'master' into next 2008-11-14 11:29:12 +11:00
compat.c Merge branches 'timers/clocksource', 'timers/hrtimers', 'timers/nohz', 'timers/ntp', 'timers/posixtimers' and 'timers/debug' into v28-timers-for-linus 2008-10-20 13:14:06 +02:00
configs.c kernel/configs.c: remove useless comments 2008-10-20 08:52:34 -07:00
cpu.c cpumask: introduce new API, without changing anything 2008-11-06 09:05:33 +01:00
cpuset.c cpuset: use seq_*mask_* to print masks 2008-10-20 08:52:39 -07:00
cred-internals.h CRED: Inaugurate COW credentials 2008-11-14 10:39:23 +11:00
cred.c User namespaces: set of cleanups (v2) 2008-11-24 18:57:41 -05:00
delayacct.c per-task-delay-accounting: update taskstats for memory reclaim delay 2008-07-25 10:53:47 -07:00
dma-coherent.c dma-coherent: export dma_[alloc|release]_from_coherent methods 2008-08-22 08:34:53 +02:00
dma.c kernel/dma.c: remove a CVS keyword 2008-10-16 11:21:30 -07:00
exec_domain.c proc: move /proc/execdomains to kernel/exec_domain.c 2008-10-23 14:30:41 +04:00
exit.c Merge branch 'master' into next 2008-11-18 18:52:37 +11:00
extable.c
fork.c User namespaces: set of cleanups (v2) 2008-11-24 18:57:41 -05:00
freezer.c freezer_cg: use thaw_process() in unfreeze_cgroup() 2008-10-30 11:38:45 -07:00
futex_compat.c CRED: Use RCU to access another task's creds and to release a task's own creds 2008-11-14 10:39:19 +11:00
futex.c CRED: Use RCU to access another task's creds and to release a task's own creds 2008-11-14 10:39:19 +11:00
hrtimer.c hrtimer: clean up unused callback modes 2008-11-12 09:54:40 +01:00
itimer.c timers: fix itimer/many thread hang 2008-09-14 16:25:35 +02:00
kallsyms.c kernel/kallsyms.c: fix double return 2008-10-16 11:21:32 -07:00
Kconfig.freezer container freezer: implement freezer cgroup subsystem 2008-10-20 08:52:34 -07:00
Kconfig.hz sched: fix SCHED_HRTICK dependency 2008-07-28 14:37:38 +02:00
Kconfig.preempt
kexec.c kexec: fix crash_save_vmcoreinfo_init build problem 2008-10-20 15:28:50 -07:00
kfifo.c
kgdb.c kgdb: call touch_softlockup_watchdog on resume 2008-10-06 13:50:59 -05:00
kmod.c CRED: Inaugurate COW credentials 2008-11-14 10:39:23 +11:00
kprobes.c kernel/kprobes.c: don't pad kretprobe_table_locks[] on uniprocessor builds 2008-11-12 17:17:17 -08:00
ksysfs.c profiling: dynamically enable readprofile at runtime 2008-10-16 11:21:31 -07:00
kthread.c Merge branch 'tracing-v28-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2008-10-20 13:35:07 -07:00
latencytop.c
lockdep_internals.h lockdep: build fix 2008-08-13 12:55:10 +02:00
lockdep_proc.c lockstat: fix numerical output rounding error 2008-08-26 10:37:46 +02:00
lockdep.c lockdep: fix irqs on/off ip tracing 2008-10-28 11:19:07 +01:00
Makefile Merge branch 'master' into next 2008-11-18 18:52:37 +11:00
marker.c markers: bit-field is not thread-safe nor smp-safe 2008-10-14 10:38:45 +02:00
module.c Merge branch 'proc' of git://git.kernel.org/pub/scm/linux/kernel/git/adobriyan/proc 2008-10-23 12:04:37 -07:00
mutex-debug.c
mutex-debug.h
mutex.c locking: fix mutex @key parameter kernel-doc notation 2008-07-28 18:12:36 +02:00
mutex.h
notifier.c ftrace: ignore functions that cannot be kprobe-ed 2008-10-14 10:34:22 +02:00
ns_cgroup.c cgroup_clone: use pid of newly created task for new cgroup 2008-07-25 10:53:37 -07:00
nsproxy.c User namespaces: set of cleanups (v2) 2008-11-24 18:57:41 -05:00
panic.c Make panic= and panic_on_oops into core_params 2008-10-22 10:00:25 +11:00
params.c Fix compile warning in kernel/params.c 2008-10-23 12:09:00 -07:00
pid_namespace.c pid_ns: (BUG 11391) change ->child_reaper when init->group_leader exits 2008-09-02 19:21:38 -07:00
pid.c pidns: remove now unused find_pid function. 2008-07-25 10:53:45 -07:00
pm_qos_params.c pm_qos_requirement might sleep 2008-09-02 19:21:40 -07:00
posix-cpu-timers.c timers: fix itimer/many thread hang, v2 2008-09-23 13:38:44 +02:00
posix-timers.c Merge branch 'timers/range-hrtimers' into v28-range-hrtimers-for-linus-v2 2008-10-22 09:48:06 +02:00
printk.c printk: remove unused code from kernel/printk.c 2008-10-23 21:54:29 +02:00
profile.c kernel/profile: fix profile_init() section mismatch 2008-10-30 11:38:46 -07:00
ptrace.c CRED: Inaugurate COW credentials 2008-11-14 10:39:23 +11:00
rcuclassic.c rcu: RCU-based detection of stalled CPUs for Classic RCU, fix 2008-10-03 10:41:00 +02:00
rcupdate.c rcupdate: fix bug of rcu_barrier*() 2008-10-21 15:59:53 +02:00
rcupreempt_trace.c rcu: trace fix possible mem-leak 2008-08-15 17:54:40 +02:00
rcupreempt.c byteorder: remove direct includes of linux/byteorder/swab[b].h 2008-10-20 08:52:40 -07:00
rcutorture.c byteorder: remove direct includes of linux/byteorder/swab[b].h 2008-10-20 12:51:53 -07:00
relay.c relay: fix "full buffer with exactly full last subbuffer" accounting problem 2008-08-05 14:33:46 -07:00
res_counter.c cgroup files: convert res_counter_write() to be a cgroups write_string() handler 2008-07-25 10:53:36 -07:00
resource.c reserve_region_with_split: Fix GFP_KERNEL usage under spinlock 2008-11-01 09:53:58 -07:00
rtmutex_common.h
rtmutex-debug.c
rtmutex-debug.h
rtmutex-tester.c sysdev: Pass the attribute to the low level sysdev show/store function 2008-07-21 21:55:02 -07:00
rtmutex.c hrtimer: convert kernel/* to the new hrtimer apis 2008-09-05 21:35:13 -07:00
rtmutex.h
rwsem.c
sched_clock.c sched_clock: prevent scd->clock from moving backwards 2008-10-10 11:17:04 +02:00
sched_cpupri.c sched: use a 2-d bitmap for searching lowest-pri CPU 2008-06-06 15:19:28 +02:00
sched_cpupri.h sched: fix the cpuprio count really 2008-06-06 15:19:44 +02:00
sched_debug.c sched: clean up debug info 2008-11-10 10:51:51 +01:00
sched_fair.c sched: release buddies on yield 2008-11-11 11:57:22 +01:00
sched_features.h sched: backward looking buddy 2008-11-05 10:30:14 +01:00
sched_idletask.c sched: add CONFIG_SMP consistency 2008-10-22 10:01:52 +02:00
sched_rt.c Merge commit 'v2.6.28-rc1' into sched/urgent 2008-10-24 12:48:46 +02:00
sched_stats.h Merge branch 'proc' of git://git.kernel.org/pub/scm/linux/kernel/git/adobriyan/proc 2008-10-23 12:04:37 -07:00
sched.c Merge branch 'master' into next 2008-11-14 11:29:12 +11:00
seccomp.c
semaphore.c semaphore: __down_common: use signal_pending_state() 2008-08-05 14:33:47 -07:00
signal.c CRED: Inaugurate COW credentials 2008-11-14 10:39:23 +11:00
smp.c generic-ipi: fix the smp_mb() placement 2008-11-06 08:41:56 +01:00
softirq.c irq: call __irq_enter() before calling the tick_idle_check 2008-11-10 22:36:39 +01:00
softlockup.c Make the taint flags reliable 2008-10-16 11:21:31 -07:00
spinlock.c lockdep: spin_lock_nest_lock(), checkpatch fixes 2008-08-13 13:56:51 +02:00
srcu.c
stacktrace.c stacktrace: fix modular build, export print_stack_trace and save_stack_trace 2008-06-30 09:20:55 +02:00
stop_machine.c stop_machine: fix race with return value (fixes Bug #11989) 2008-11-16 15:09:52 -08:00
sys_ni.c Configure out AIO support 2008-10-16 11:21:51 -07:00
sys.c User namespaces: set of cleanups (v2) 2008-11-24 18:57:41 -05:00
sysctl_check.c sysctl: check for bogus modes 2008-07-25 10:53:45 -07:00
sysctl.c CRED: Wrap task credential accesses in the core kernel 2008-11-14 10:39:12 +11:00
taskstats.c taskstats: remove initialization of static per-cpu variable 2008-07-25 10:53:47 -07:00
test_kprobes.c
time.c select: add a timespec_add_safe() function 2008-09-05 21:34:57 -07:00
timeconst.pl
timer.c Merge branch 'master' into next 2008-11-14 11:29:12 +11:00
tracepoint.c tracepoint: check if the probe has been registered 2008-10-27 16:45:46 +01:00
tsacct.c CRED: Use RCU to access another task's creds and to release a task's own creds 2008-11-14 10:39:19 +11:00
uid16.c CRED: Wrap current->cred and a few other accessors 2008-11-14 10:39:18 +11:00
user_namespace.c User namespaces: set of cleanups (v2) 2008-11-24 18:57:41 -05:00
user.c User namespaces: set of cleanups (v2) 2008-11-24 18:57:41 -05:00
utsname_sysctl.c sysctl: simplify ->strategy 2008-10-16 11:21:47 -07:00
utsname.c removed unused #include <linux/version.h>'s 2008-08-23 12:14:12 -07:00
wait.c wait: kill is_sync_wait() 2008-10-16 11:21:31 -07:00
workqueue.c Merge branch 'master' into next 2008-11-14 11:29:12 +11:00