linux/kernel
Mikulas Patocka e79323bd87 user namespace: fix incorrect memory barriers
smp_read_barrier_depends() can be used if there is data dependency between
the readers - i.e. if the read operation after the barrier uses address
that was obtained from the read operation before the barrier.

In this file, there is only control dependency, no data dependecy, so the
use of smp_read_barrier_depends() is incorrect. The code could fail in the
following way:
* the cpu predicts that idx < entries is true and starts executing the
  body of the for loop
* the cpu fetches map->extent[0].first and map->extent[0].count
* the cpu fetches map->nr_extents
* the cpu verifies that idx < extents is true, so it commits the
  instructions in the body of the for loop

The problem is that in this scenario, the cpu read map->extent[0].first
and map->nr_extents in the wrong order. We need a full read memory barrier
to prevent it.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-14 16:03:02 -07:00
..
debug mm: per-thread vma caching 2014-04-07 16:35:53 -07:00
events Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm 2014-04-05 13:20:43 -07:00
gcov gcov: reuse kbasename helper 2013-11-13 12:09:34 +09:00
irq genirq: Export symbol no_action() 2014-03-22 11:33:09 +01:00
locking lglock: map to spinlock when !CONFIG_SMP 2014-04-07 16:36:14 -07:00
power kernel: use macros from compiler.h instead of __attribute__((...)) 2014-04-07 16:36:11 -07:00
printk printk: fix one circular lockdep warning about console_lock 2014-04-03 16:21:08 -07:00
rcu Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-03-31 11:21:19 -07:00
sched Merge branch 'akpm' (incoming from Andrew) 2014-04-07 16:38:06 -07:00
time kernel: use macros from compiler.h instead of __attribute__((...)) 2014-04-07 16:36:11 -07:00
trace Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-04-12 14:49:50 -07:00
.gitignore Ignore generated file kernel/x509_certificate_list 2013-12-10 18:21:34 +00:00
acct.c
async.c
audit_tree.c inotify: Fix reporting of cookies for inotify events 2014-02-18 11:17:17 +01:00
audit_watch.c inotify: Fix reporting of cookies for inotify events 2014-02-18 11:17:17 +01:00
audit.c Merge git://git.infradead.org/users/eparis/audit 2014-04-12 12:38:53 -07:00
audit.h audit: Use struct net not pid_t to remember the network namespce to reply in 2014-03-20 10:10:53 -04:00
auditfilter.c Merge git://git.infradead.org/users/eparis/audit 2014-04-12 12:38:53 -07:00
auditsc.c Merge git://git.infradead.org/users/eparis/audit 2014-04-12 12:38:53 -07:00
backtracetest.c
bounds.c mm: do not allocate page->ptl dynamically, if spinlock_t fits to long 2013-12-20 12:25:45 -08:00
capability.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2014-04-03 09:26:18 -07:00
cgroup_freezer.c cgroup: drop const from @buffer of cftype->write_string() 2014-03-19 10:23:54 -04:00
cgroup.c cgroup: newly created dirs and files should be owned by the creator 2014-04-07 16:44:47 -04:00
compat.c Merge branch 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-04-02 12:51:41 -07:00
configs.c
context_tracking.c context_tracking: Wrap static key check into more intuitive function name 2013-12-02 20:43:14 +01:00
cpu_pm.c
cpu.c CPU hotplug: Provide lockless versions of callback registration functions 2014-03-20 13:43:40 +01:00
cpuset.c Merge branch 'akpm' (incoming from Andrew) 2014-04-03 16:22:16 -07:00
crash_dump.c
cred.c
delayacct.c kernel/delayacct.c: remove redundant checking in __delayacct_add_tsk() 2013-11-13 12:09:12 +09:00
dma.c
elfcore.c switch elf_core_write_extra_phdrs() to dump_emit() 2013-11-09 00:16:23 -05:00
exec_domain.c
exit.c wait: WSTOPPED|WCONTINUED doesn't work if a zombie leader is traced by another process 2014-04-07 16:36:06 -07:00
extable.c asmlinkage: Make main_extable_sort_needed visible 2014-02-13 18:13:22 -08:00
fork.c kernel: use macros from compiler.h instead of __attribute__((...)) 2014-04-07 16:36:11 -07:00
freezer.c libata, freezer: avoid block device removal while system is frozen 2013-12-19 13:50:32 -05:00
futex_compat.c compat: Get rid of (get|put)_compat_time(val|spec) 2014-02-02 14:09:12 -08:00
futex.c futex: update documentation for ordering guarantees 2014-04-12 17:57:51 -07:00
groups.c kernel/groups.c: remove return value of set_groups 2014-04-03 16:21:05 -07:00
hrtimer.c timer: Remove code redundancy while calling get_nohz_timer_target() 2014-03-20 12:35:46 +01:00
hung_task.c kernel: audit/fix non-modular users of module_init in core code 2014-04-03 16:21:07 -07:00
irq_work.c perf/x86: Warn to early_printk() in case irq_work is too slow 2014-02-21 21:49:07 +01:00
itimer.c
jump_label.c static_key: WARN on usage before jump_label_init was called 2013-10-19 19:45:35 -04:00
kallsyms.c kernel: use macros from compiler.h instead of __attribute__((...)) 2014-04-07 16:36:11 -07:00
kcmp.c
Kconfig.freezer
Kconfig.hz kernel: remove CONFIG_USE_GENERIC_SMP_HELPERS 2013-11-15 09:32:22 +09:00
Kconfig.locks
Kconfig.preempt
kexec.c kernel: use macros from compiler.h instead of __attribute__((...)) 2014-04-07 16:36:11 -07:00
kmod.c execve: use 'struct filename *' for executable name passing 2014-02-05 12:54:53 -08:00
kprobes.c kprobes: use KSYM_NAME_LEN to size identifier buffers 2013-11-13 12:09:26 +09:00
ksysfs.c kernel: use macros from compiler.h instead of __attribute__((...)) 2014-04-07 16:36:11 -07:00
kthread.c kthread: ensure locality of task_struct allocations 2014-04-03 16:20:49 -07:00
latencytop.c
Makefile Merge branch 'x86-asmlinkage-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-03-31 14:13:25 -07:00
module_signing.c keys: change asymmetric keys to use common hash definitions 2013-10-25 17:15:18 -04:00
module-internal.h KEYS: Separate the kernel signature checking keyring from module signing 2013-09-25 17:17:01 +01:00
module.c modules: use raw_cpu_write for initialization of per cpu refcount. 2014-04-07 16:36:14 -07:00
notifier.c notifier: Substitute rcu_access_pointer() for rcu_dereference_raw() 2014-02-26 06:35:13 -08:00
nsproxy.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2013-09-07 14:35:32 -07:00
padata.c padata: Fix wrong usage of rcu_dereference() 2013-12-05 21:28:42 +08:00
panic.c kernel/panic.c: display reason at end + pr_emerg 2014-04-07 16:36:08 -07:00
params.c params: improve standard definitions 2013-12-04 14:09:46 +10:30
pid_namespace.c pid_namespace: pidns_get() should check task_active_pid_ns() != NULL 2014-04-02 16:20:21 -07:00
pid.c pidns: fix free_pid() to handle the first fork failure 2013-09-30 14:31:03 -07:00
posix-cpu-timers.c posix-timers: Convert abuses of BUG_ON to WARN_ON 2013-12-09 16:56:29 +01:00
posix-timers.c
profile.c CPU hotplug notifiers registration fixes for 3.15-rc1 2014-04-07 14:55:46 -07:00
ptrace.c kernel/compat: convert to COMPAT_SYSCALL_DEFINE 2014-03-06 15:35:10 +01:00
range.c
reboot.c kexec: migrate to reboot cpu 2013-12-18 19:04:50 -08:00
relay.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-04-12 14:49:50 -07:00
res_counter.c res_counter: remove interface for locked charging and uncharging 2014-04-07 16:35:54 -07:00
resource.c kernel/resource.c: make reallocate_resource() static 2014-04-03 16:21:07 -07:00
seccomp.c Merge git://git.infradead.org/users/eparis/audit 2014-04-12 12:38:53 -07:00
signal.c kernel: use macros from compiler.h instead of __attribute__((...)) 2014-04-07 16:36:11 -07:00
smp.c smp: Rename __smp_call_function_single() to smp_call_function_single_async() 2014-02-24 14:47:15 -08:00
smpboot.c kernel: delete __cpuinit usage from all core kernel files 2013-07-14 19:36:59 -04:00
smpboot.h
softirq.c softirq: Add linux/irq.h to make it compile again 2014-03-19 11:28:14 +01:00
stacktrace.c
stop_machine.c stop_machine: Fix^2 race between stop_two_cpus() and stop_cpus() 2014-03-11 11:33:47 +01:00
sys_ni.c fs, kernel: permit disabling the uselib syscall 2014-04-03 16:21:05 -07:00
sys.c mm, thp: add VM_INIT_DEF_MASK and PRCTL_THP_DISABLE 2014-04-07 16:35:52 -07:00
sysctl_binary.c kernel/sysctl_binary.c: use scnprintf() instead of snprintf() 2013-11-13 12:09:33 +09:00
sysctl.c hung_task: check the value of "sysctl_hung_task_timeout_sec" 2014-04-07 16:36:07 -07:00
system_certificates.S KEYS: correct alignment of system_certificate_list content in assembly file 2013-12-10 18:25:28 +00:00
system_keyring.c KEYS: correct alignment of system_certificate_list content in assembly file 2013-12-10 18:25:28 +00:00
task_work.c task_work: documentation 2013-09-11 15:58:27 -07:00
taskstats.c genetlink: only pass array to genl_register_family_with_ops() 2013-11-19 16:39:05 -05:00
test_kprobes.c
time.c
timeconst.bc
timer.c Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-04-01 11:00:07 -07:00
torture.c rcutorture: Gracefully handle NULL cleanup hooks 2014-02-23 09:04:39 -08:00
tracepoint.c This includes the final patch to clean up and fix the issue with the 2014-04-12 13:06:10 -07:00
tsacct.c
uid16.c userns: Kill nsown_capable it makes the wrong thing easy 2013-08-30 23:44:11 -07:00
up.c smp: Rename __smp_call_function_single() to smp_call_function_single_async() 2014-02-24 14:47:15 -08:00
user_namespace.c user namespace: fix incorrect memory barriers 2014-04-14 16:03:02 -07:00
user-return-notifier.c
user.c kernel: audit/fix non-modular users of module_init in core code 2014-04-03 16:21:07 -07:00
utsname_sysctl.c
utsname.c userns: Kill nsown_capable it makes the wrong thing easy 2013-08-30 23:44:11 -07:00
watchdog.c kernel/watchdog.c: touch_nmi_watchdog should only touch local cpu not every one 2014-04-03 16:20:58 -07:00
workqueue_internal.h
workqueue.c Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-04-01 11:00:07 -07:00