linux-uconsole/kernel
Michal Hocko 29540fc633 futex: futex_find_get_task remove credentails check
commit 7a0ea09ad5 upstream.

futex_find_get_task is currently used (through lookup_pi_state) from two
contexts, futex_requeue and futex_lock_pi_atomic.  None of the paths
looks it needs the credentials check, though.  Different (e)uids
shouldn't matter at all because the only thing that is important for
shared futex is the accessibility of the shared memory.

The credentail check results in glibc assert failure or process hang (if
glibc is compiled without assert support) for shared robust pthread
mutex with priority inheritance if a process tries to lock already held
lock owned by a process with a different euid:

pthread_mutex_lock.c:312: __pthread_mutex_lock_full: Assertion `(-(e)) != 3 || !robust' failed.

The problem is that futex_lock_pi_atomic which is called when we try to
lock already held lock checks the current holder (tid is stored in the
futex value) to get the PI state.  It uses lookup_pi_state which in turn
gets task struct from futex_find_get_task.  ESRCH is returned either
when the task is not found or if credentials check fails.

futex_lock_pi_atomic simply returns if it gets ESRCH.  glibc code,
however, doesn't expect that robust lock returns with ESRCH because it
should get either success or owner died.

Signed-off-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Darren Hart <dvhltc@us.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-02 10:21:24 -07:00
..
gcov microblaze: Enable GCOV_PROFILE_ALL 2009-09-21 14:29:21 +02:00
irq genirq: Deal with desc->set_type() changing desc->chip 2010-08-02 10:20:52 -07:00
power Freezer: Fix buggy resume test for tasks frozen with cgroup freezer 2010-04-26 07:41:17 -07:00
time hrtimer: Tune hrtimer_interrupt hang logic 2010-04-01 15:58:14 -07:00
trace tracing: Fix ftrace_event_call alignment for use with gcc 4.5 2010-05-12 14:57:14 -07:00
.gitignore
acct.c bsdacct: fix uid/gid misreporting 2009-12-18 14:03:52 -08:00
async.c async: Fix lack of boot-time console due to insufficient synchronization 2009-06-08 12:31:53 -07:00
audit.c Audit: send signal info if selinux is disabled 2009-09-24 03:50:26 -04:00
audit.h Fix rule eviction order for AUDIT_DIR 2009-06-24 00:02:38 -04:00
audit_tree.c fix more leaks in audit_tree.c tag_chunk() 2010-01-18 10:19:50 -08:00
audit_watch.c Audit: reorganize struct audit_watch to save 8 bytes 2009-09-24 03:50:25 -04:00
auditfilter.c Audit: clean up all op= output to include string quoting 2009-06-24 00:00:52 -04:00
auditsc.c Audit: rearrange audit_context to save 16 bytes per struct 2009-09-24 03:50:26 -04:00
backtracetest.c
bounds.c
capability.c
cgroup.c cgroups: fix 2.6.32 regression causing BUG_ON() in cgroup_diput() 2010-01-18 10:19:32 -08:00
cgroup_freezer.c Freezer: Fix buggy resume test for tasks frozen with cgroup freezer 2010-04-26 07:41:17 -07:00
compat.c cpumask: fix compat getaffinity 2010-07-05 11:10:27 -07:00
configs.c
cpu.c timers, init: Limit the number of per cpu calibration bootup messages 2010-01-28 15:01:14 -08:00
cpuset.c cpuset: fix the problem that cpuset_mem_spread_node() returns an offline node 2010-04-01 15:58:46 -07:00
cred-internals.h
cred.c CRED: Fix a race in creds_are_invalid() in credentials debugging 2010-05-12 14:57:10 -07:00
delayacct.c headers: taskstats_kern.h trim 2009-09-18 09:48:52 -07:00
dma.c
exec_domain.c
exit.c connector: fix regression introduced by sid connector 2009-10-29 07:39:25 -07:00
extable.c
fork.c revert "procfs: provide stack information for threads" and its fixup commits 2010-05-26 14:29:19 -07:00
freezer.c sched: fix nr_uninterruptible accounting of frozen tasks really 2009-07-18 14:19:53 +02:00
futex.c futex: futex_find_get_task remove credentails check 2010-08-02 10:21:24 -07:00
futex_compat.c futex: Fix compat_futex to be same as futex for REQUEUE_PI 2009-08-10 15:41:12 +02:00
groups.c groups: move code to kernel/groups.c 2009-06-16 19:47:48 -07:00
hrtimer.c hrtimer: Tune hrtimer_interrupt hang logic 2010-04-01 15:58:14 -07:00
hung_task.c sysctl: remove "struct file *" argument of ->proc_handler 2009-09-24 07:21:04 -07:00
itimer.c itimers: Add tracepoints for itimer 2009-08-29 14:10:07 +02:00
kallsyms.c kallsyms: use new arch_is_kernel_text() 2009-09-23 07:39:30 -07:00
Kconfig.freezer
Kconfig.hz
Kconfig.preempt
kexec.c kexec: fix omitting offset in extended crashkernel syntax 2009-07-29 19:10:34 -07:00
kfifo.c kfifo: Use "const" definitions 2009-09-19 13:13:17 -07:00
kgdb.c sysrq, intel_fb: fix sysrq g collision 2009-05-15 07:56:24 -05:00
kmod.c Revert "kmod: fix race in usermodehelper code" 2009-09-23 18:12:10 -07:00
kprobes.c const: constify remaining file_operations 2009-10-01 16:11:11 -07:00
ksysfs.c
kthread.c cpuset: fix the problem that cpuset_mem_spread_node() returns an offline node 2010-04-01 15:58:46 -07:00
latencytop.c
lockdep.c Revert "lockdep: fix incorrect percpu usage" 2010-06-01 09:45:46 -07:00
lockdep_internals.h lockdep: BFS cleanup 2009-07-24 10:53:29 +02:00
lockdep_proc.c seq_file: constify seq_operations 2009-09-23 07:39:29 -07:00
lockdep_states.h
Makefile SLOW_WORK: Move slow_work's proc file to debugfs 2009-12-01 08:20:31 -08:00
module.c dynamic debug: move ddebug_remove_module() down into free_module() 2010-08-02 10:20:47 -07:00
mutex-debug.c headers: remove sched.h from interrupt.h 2009-10-11 11:20:58 -07:00
mutex-debug.h
mutex.c mutex: Fix optimistic spinning vs. BKL 2010-07-05 11:10:31 -07:00
mutex.h
notifier.c
ns_cgroup.c cgroups: let ss->can_attach and ss->attach do whole threadgroups at a time 2009-09-24 07:20:58 -07:00
nsproxy.c nsproxy: extract create_nsproxy() 2009-06-18 13:03:56 -07:00
panic.c Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-10-08 12:16:35 -07:00
params.c param: fix setting arrays of bool 2009-10-29 08:56:20 +10:30
perf_event.c Fix racy use of anon_inode_getfd() in perf_event.c 2010-07-05 11:10:30 -07:00
pid.c mm: also use alloc_large_system_hash() for the PID hash table 2009-09-22 07:17:38 -07:00
pid_namespace.c pidns: deny CLONE_PARENT|CLONE_NEWPID combination 2009-09-24 07:21:04 -07:00
pm_qos_params.c
posix-cpu-timers.c itimers: Add tracepoints for itimer 2009-08-29 14:10:07 +02:00
posix-timers.c posix_timer: Fix error path in timer_create 2010-07-05 11:10:30 -07:00
printk.c printk: add printk_delay to make messages readable for some scenarios 2009-09-23 07:39:28 -07:00
profile.c profile: fix stats and data leakage 2010-05-26 14:29:18 -07:00
ptrace.c ptrace: __ptrace_detach: do __wake_up_parent() if we reap the tracee 2009-09-24 07:20:59 -07:00
rcupdate.c rcu: Move rcu_barrier() to rcutree 2009-10-07 08:11:20 +02:00
rcutorture.c rcu: Clean up code to address Ingo's checkpatch feedback 2009-09-23 19:46:30 +02:00
rcutree.c rcu: Fix note_new_gpnum() uses of ->gpnum 2009-12-18 14:03:01 -08:00
rcutree.h rcu: Remove inline from forward-referenced functions 2009-12-18 14:03:04 -08:00
rcutree_plugin.h rcu: Remove inline from forward-referenced functions 2009-12-18 14:03:04 -08:00
rcutree_trace.c rcu: Make hot-unplugged CPU relinquish its own RCU callbacks 2009-10-07 08:11:20 +02:00
relay.c const: mark struct vm_struct_operations 2009-09-27 11:39:25 -07:00
res_counter.c memcg: some modification to softlimit under hierarchical memory reclaim. 2009-10-01 16:11:13 -07:00
resource.c walk system ram range 2009-09-23 07:39:41 -07:00
rtmutex-debug.c
rtmutex-debug.h
rtmutex-tester.c
rtmutex.c rtmutex: Avoid deadlock in rt_mutex_start_proxy_lock() 2009-08-06 05:50:21 +02:00
rtmutex.h
rtmutex_common.h
rwsem.c
sched.c sched: Fix over-scheduling bug 2010-08-02 10:20:52 -07:00
sched_clock.c sched: Fix cpu_clock() in NMIs, on !CONFIG_HAVE_UNSTABLE_SCHED_CLOCK 2010-01-22 15:18:30 -08:00
sched_cpupri.c sched: Add new prio to cpupri before removing old prio 2009-08-02 14:26:09 +02:00
sched_cpupri.h
sched_debug.c sched: Rate-limit newidle 2009-12-18 14:03:13 -08:00
sched_fair.c sched: Fix missing sched tunable recalculation on cpu add/remove 2010-01-28 15:01:11 -08:00
sched_features.h sched: Add new wakeup preemption mode: WAKEUP_RUNNING 2009-09-17 10:17:25 +02:00
sched_idletask.c sched: Simplify sys_sched_rr_get_interval() system call 2009-09-21 09:53:55 +02:00
sched_rt.c sched: Simplify sys_sched_rr_get_interval() system call 2009-09-21 09:53:55 +02:00
sched_stats.h
seccomp.c
semaphore.c
signal.c signals: check_kill_permission(): don't check creds if same_thread_group() 2010-07-05 11:10:56 -07:00
slow-work-debugfs.c SLOW_WORK: Move slow_work's proc file to debugfs 2009-12-01 08:20:31 -08:00
slow-work.c SLOW_WORK: Move slow_work's proc file to debugfs 2009-12-01 08:20:31 -08:00
slow-work.h SLOW_WORK: Move slow_work's proc file to debugfs 2009-12-01 08:20:31 -08:00
smp.c cpumask: remove arch_send_call_function_ipi 2009-09-24 09:34:47 +09:30
softirq.c softirq: add BLOCK_IOPOLL to softirq_to_name 2009-09-17 15:53:44 -04:00
softlockup.c softlockup: Stop spurious softlockup messages due to overflow 2010-04-01 15:58:47 -07:00
spinlock.c locking: Allow arch-inlined spinlocks 2009-08-31 18:08:50 +02:00
srcu.c
stacktrace.c
stop_machine.c
sys.c Merge branch 'hwpoison-2.6.32' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6 2009-10-29 08:20:00 -07:00
sys_ni.c Merge branch 'master' of /home/davem/src/GIT/linux-2.6/ 2009-09-24 15:13:11 -07:00
sysctl.c kernel/sysctl.c: fix stable merge error in NOMMU mmap_min_addr 2010-01-18 10:19:49 -08:00
sysctl_check.c NET: fix oops at bootime in sysctl code 2010-02-09 04:51:02 -08:00
taskstats.c genetlink: make netns aware 2009-07-12 14:03:27 -07:00
test_kprobes.c
time.c time: Prevent 32 bit overflow with set_normalized_timespec() 2009-09-15 10:17:30 +02:00
timeconst.pl
timer.c Merge branch 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-23 09:46:15 -07:00
tracepoint.c trivial: fix typo "to to" in multiple files 2009-09-21 15:14:55 +02:00
tsacct.c
uid16.c headers: utsname.h redux 2009-09-23 18:13:10 -07:00
up.c
user.c uids: Prevent tear down race 2009-11-02 16:02:39 +01:00
user_namespace.c
utsname.c utsns: extract creeate_uts_ns() 2009-06-18 13:03:55 -07:00
utsname_sysctl.c sysctl: remove "struct file *" argument of ->proc_handler 2009-09-24 07:21:04 -07:00
wait.c locking, sched: Give waitqueue spinlocks their own lockdep classes 2009-08-10 14:43:09 +02:00
workqueue.c workqueue: fix race condition in schedule_on_each_cpu() 2009-11-17 17:40:33 -08:00