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153fbd1226
linux/kernel
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Peter Zijlstra 153fbd1226 futex: Fix more put_pi_state() vs. exit_pi_state_list() races 
Dmitry (through syzbot) reported being able to trigger the WARN in
get_pi_state() and a use-after-free on:

	raw_spin_lock_irq(&pi_state->pi_mutex.wait_lock);

Both are due to this race:

  exit_pi_state_list()				put_pi_state()

  lock(&curr->pi_lock)
  while() {
	pi_state = list_first_entry(head);
	hb = hash_futex(&pi_state->key);
	unlock(&curr->pi_lock);

						dec_and_test(&pi_state->refcount);

	lock(&hb->lock)
	lock(&pi_state->pi_mutex.wait_lock)	// uaf if pi_state free'd
	lock(&curr->pi_lock);

	....

	unlock(&curr->pi_lock);
	get_pi_state();				// WARN; refcount==0

The problem is we take the reference count too late, and don't allow it
being 0. Fix it by using inc_not_zero() and simply retrying the loop
when we fail to get a refcount. In that case put_pi_state() should
remove the entry from the list.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Gratian Crisan <gratian.crisan@ni.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: dvhart@infradead.org
Cc: syzbot <bot+2af19c9e1ffe4d4ee1d16c56ae7580feaee75765@syzkaller.appspotmail.com>
Cc: syzkaller-bugs@googlegroups.com
Cc: <stable@vger.kernel.org>
Fixes: c74aef2d06 ("futex: Fix pi_state->owner serialization")
Link: http://lkml.kernel.org/r/20171031101853.xpfh72y643kdfhjs@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-01 09:05:00 +01:00
..
bpf bpf: rename sk_actions to align with bpf infrastructure 2017-10-29 11:18:48 +09:00
cgroup Revert "net: defer call to cgroup_sk_alloc()" 2017-10-10 20:24:29 -07:00
configs ANDROID: binder: add hwbinder,vndbinder to BINDER_DEVICES. 2017-08-22 18:43:23 -07:00
debug sched/headers: Prepare for new header dependencies before moving code to <linux/sched/debug.h> 2017-03-02 08:42:34 +01:00
events perf/core: Fix cgroup time when scheduling descendants 2017-10-10 10:06:55 +02:00
gcov gcov: support GCC 7.1 2017-05-12 15:57:15 -07:00
irq irqchip updates for 4.14-rc5 2017-10-16 10:26:46 +02:00
livepatch livepatch: unpatch all klp_objects if klp_module_coming fails 2017-10-11 15:38:46 +02:00
locking locking/lockdep: Fix stacktrace mess 2017-10-10 10:04:28 +02:00
power PM / s2idle: Invoke the ->wake() platform callback earlier 2017-09-29 01:26:13 +02:00
printk Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk 2017-09-07 21:00:52 -07:00
rcu doc: Fix various RCU docbook comment-header problems 2017-10-19 22:26:11 -04:00
sched membarrier: Provide register expedited private command 2017-10-19 22:13:40 -04:00
time drivers/pps: aesthetic tweaks to PPS-related content 2017-09-08 18:26:51 -07:00
trace Two updates. 2017-10-04 08:34:01 -07:00
.gitignore
acct.c fs: make the buf argument to __kernel_write a void pointer 2017-09-04 19:05:15 -04:00
async.c async: Adjust system_state checks 2017-05-23 10:01:37 +02:00
audit_fsnotify.c Merge branch 'fsnotify' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2017-05-03 11:05:15 -07:00
audit_tree.c Merge branch 'fsnotify' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2017-05-03 11:05:15 -07:00
audit_watch.c audit/stable-4.13 PR 20170816 2017-08-16 16:48:34 -07:00
audit.c audit: update the function comments 2017-09-05 09:46:59 -04:00
audit.h ipc: mqueue: Replace timespec with timespec64 2017-09-03 20:21:24 -04:00
auditfilter.c audit: kernel generated netlink traffic should have a portid of 0 2017-05-02 10:16:05 -04:00
auditsc.c Merge branch 'work.ipc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-09-14 17:37:26 -07:00
backtracetest.c
bounds.c
capability.c
compat.c semtimedop(): move compat to native 2017-07-15 20:46:47 -04:00
configs.c
context_tracking.c
cpu_pm.c PM / CPU: replace raw_notifier with atomic_notifier 2017-07-31 13:09:49 +02:00
cpu.c cpu/hotplug: Reset node state after operation 2017-10-21 16:11:30 +02:00
crash_core.c kdump: protect vmcoreinfo data under the crash memory 2017-07-12 16:26:00 -07:00
crash_dump.c
cred.c doc: ReSTify credentials.txt 2017-05-18 10:30:19 -06:00
delayacct.c sched/headers: Prepare to move cputime functionality from <linux/sched.h> into <linux/sched/cputime.h> 2017-03-02 08:42:39 +01:00
dma.c
elfcore.c
exec_domain.c
exit.c waitid(): Avoid unbalanced user_access_end() on access_ok() error 2017-10-20 15:32:54 -04:00
extable.c extable: Enable RCU if it is not watching in kernel_text_address() 2017-09-23 16:50:20 -04:00
fork.c kmemleak: clear stale pointers from task stacks 2017-10-13 16:18:33 -07:00
freezer.c
futex_compat.c
futex.c futex: Fix more put_pi_state() vs. exit_pi_state_list() races 2017-11-01 09:05:00 +01:00
groups.c kernel/groups.c: use sort library function 2017-07-10 16:32:34 -07:00
hung_task.c kernel/hung_task.c: defer showing held locks 2017-05-08 17:15:10 -07:00
irq_work.c
jump_label.c jump_label: Provide hotplug context variants 2017-08-10 12:28:59 +02:00
kallsyms.c kernel/kallsyms.c: replace all_var with IS_ENABLED(CONFIG_KALLSYMS_ALL) 2017-07-10 16:32:34 -07:00
kcmp.c kernel/kcmp.c: drop branch leftover typo 2017-10-03 17:54:25 -07:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c kcov: support compat processes 2017-09-08 18:26:51 -07:00
kexec_core.c x86/mm, kexec: Allow kexec to be used with SME 2017-07-18 11:38:04 +02:00
kexec_file.c kexec_file: adjust declaration of kexec_purgatory 2017-07-12 16:26:02 -07:00
kexec_internal.h kexec_file: adjust declaration of kexec_purgatory 2017-07-12 16:26:02 -07:00
kexec.c kdump: protect vmcoreinfo data under the crash memory 2017-07-12 16:26:00 -07:00
kmod.c kmod: move #ifdef CONFIG_MODULES wrapper to Makefile 2017-09-08 18:26:51 -07:00
kprobes.c kprobes: Ensure that jprobe probepoints are at function entry 2017-07-08 11:05:35 +02:00
ksysfs.c kexec: move vmcoreinfo out of the kernel's .bss section 2017-07-12 16:25:59 -07:00
kthread.c kernel/kthread.c: kthread_worker: don't hog the cpu 2017-08-31 16:33:15 -07:00
latencytop.c sched/headers: Prepare to move sched_info_on() and force_schedstat_enabled() from <linux/sched.h> to <linux/sched/stat.h> 2017-03-02 08:42:39 +01:00
Makefile kmod: move #ifdef CONFIG_MODULES wrapper to Makefile 2017-09-08 18:26:51 -07:00
memremap.c memremap: add scheduling point to devm_memremap_pages 2017-10-03 17:54:25 -07:00
module_signing.c
module-internal.h
module.c module: fix ddebug_remove_module() 2017-07-25 15:08:32 +02:00
notifier.c kernel/notifier.c: simplify expression 2017-02-24 17:46:56 -08:00
nsproxy.c perf: Add PERF_RECORD_NAMESPACES to include namespaces related info 2017-03-13 15:57:41 -03:00
padata.c padata: Avoid nested calls to cpus_read_lock() in pcrypt_init_padata() 2017-05-26 10:10:37 +02:00
panic.c locking/refcounts, x86/asm: Implement fast refcount overflow protection 2017-08-17 10:40:26 +02:00
params.c kernel/params.c: improve STANDARD_PARAM_DEF readability 2017-10-03 17:54:26 -07:00
pid_namespace.c userns,pidns: Verify the userns for new pid namespaces 2017-07-20 07:43:58 -05:00
pid.c pids: make task_tgid_nr_ns() safe 2017-08-21 12:47:31 -07:00
profile.c sched/headers: Prepare to move sched_info_on() and force_schedstat_enabled() from <linux/sched.h> to <linux/sched/stat.h> 2017-03-02 08:42:39 +01:00
ptrace.c signal: Remove kernel interal si_code magic 2017-07-24 14:30:28 -05:00
range.c
reboot.c
relay.c Merge branch 'work.splice' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-05-02 11:38:06 -07:00
resource.c
seccomp.c seccomp: make function __get_seccomp_filter static 2017-10-10 11:45:29 -07:00
signal.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2017-09-11 18:34:47 -07:00
smp.c treewide: make "nr_cpu_ids" unsigned 2017-09-08 18:26:48 -07:00
smpboot.c watchdog/core, powerpc: Lock cpus across reconfiguration 2017-10-04 10:53:54 +02:00
smpboot.h
softirq.c sched/core: Remove 'task' parameter and rename tsk_restore_flags() to current_restore_flags() 2017-04-11 09:06:32 +02:00
stacktrace.c stacktrace/x86: add function for detecting reliable stack traces 2017-03-08 09:18:02 +01:00
stop_machine.c stop_machine: Provide stop_machine_cpuslocked() 2017-05-26 10:10:36 +02:00
sys_ni.c
sys.c prctl: Allow local CAP_SYS_ADMIN changing exe_file 2017-07-20 07:46:07 -05:00
sysctl_binary.c fs: fix kernel_write prototype 2017-09-04 19:05:15 -04:00
sysctl.c Merge branch 'core-watchdog-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-10-06 08:36:41 -07:00
task_work.c task_work: Replace spin_unlock_wait() with lock/unlock pair 2017-07-25 10:08:58 -07:00
taskstats.c taskstats: add e/u/stime for TGID command 2017-05-08 17:15:12 -07:00
test_kprobes.c
torture.c torture: Fix typo suppressing CPU-hotplug statistics 2017-07-25 13:04:45 -07:00
tracepoint.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task.h> 2017-03-02 08:42:35 +01:00
tsacct.c sched/headers: Prepare to move cputime functionality from <linux/sched.h> into <linux/sched/cputime.h> 2017-03-02 08:42:39 +01:00
ucount.c ucount: Remove the atomicity from ucount->count 2017-03-06 15:26:37 -06:00
uid16.c sched/headers: Prepare to remove <linux/cred.h> inclusion from <linux/sched.h> 2017-03-02 08:42:31 +01:00
umh.c kmod: split out umh code into its own file 2017-09-08 18:26:50 -07:00
up.c smp: Avoid using two cache lines for struct call_single_data 2017-08-29 15:14:38 +02:00
user_namespace.c userns,pidns: Verify the userns for new pid namespaces 2017-07-20 07:43:58 -05:00
user-return-notifier.c
user.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/user.h> 2017-03-02 08:42:29 +01:00
utsname_sysctl.c sched/headers: Remove <linux/rwsem.h> from <linux/sched.h> 2017-03-03 01:45:36 +01:00
utsname.c sched/headers: Prepare to move the task_lock()/unlock() APIs to <linux/sched/task.h> 2017-03-02 08:42:38 +01:00
watchdog_hld.c watchdog/hardlockup/perf: Fix spelling mistake: "permanetely" -> "permanently" 2017-09-28 12:24:54 +02:00
watchdog.c watchdog/core: Put softlockup_threads_initialized under ifdef guard 2017-10-04 11:30:50 +02:00
workqueue_internal.h
workqueue.c workqueue: replace pool->manager_arb mutex with a flag 2017-10-10 07:13:57 -07:00