linux/kernel
John Stultz a4f8f6667f timekeeping: Cap array access in timekeeping_debug
It was reported that hibernation could fail on the 2nd attempt, where the
system hangs at hibernate() -> syscore_resume() -> i8237A_resume() ->
claim_dma_lock(), because the lock has already been taken.

However there is actually no other process would like to grab this lock on
that problematic platform.

Further investigation showed that the problem is triggered by setting
/sys/power/pm_trace to 1 before the 1st hibernation.

Since once pm_trace is enabled, the rtc becomes unmeaningful after suspend,
and meanwhile some BIOSes would like to adjust the 'invalid' RTC (e.g, smaller
than 1970) to the release date of that motherboard during POST stage, thus
after resumed, it may seem that the system had a significant long sleep time
which is a completely meaningless value.

Then in timekeeping_resume -> tk_debug_account_sleep_time, if the bit31 of the
sleep time happened to be set to 1, fls() returns 32 and we add 1 to
sleep_time_bin[32], which causes an out of bounds array access and therefor
memory being overwritten.

As depicted by System.map:
0xffffffff81c9d080 b sleep_time_bin
0xffffffff81c9d100 B dma_spin_lock
the dma_spin_lock.val is set to 1, which caused this problem.

This patch adds a sanity check in tk_debug_account_sleep_time()
to ensure we don't index past the sleep_time_bin array.

[jstultz: Problem diagnosed and original patch by Chen Yu, I've solved the
 issue slightly differently, but borrowed his excelent explanation of the
 issue here.]

Fixes: 5c83545f24 "power: Add option to log time spent in suspend"
Reported-by: Janek Kozicki <cosurgi@gmail.com>
Reported-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: linux-pm@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Xunlei Pang <xpang@redhat.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: stable <stable@vger.kernel.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Link: http://lkml.kernel.org/r/1471993702-29148-3-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-08-24 09:34:32 +02:00
..
bpf bpf: fix bpf_skb_in_cgroup helper naming 2016-08-12 21:53:33 -07:00
configs config: add android config fragments 2016-08-02 19:35:42 -04:00
debug
events perf/core: Check return value of the perf_event_read() IPI 2016-08-18 10:35:52 +02:00
gcov gcov: add support for gcc version >= 6 2016-07-15 14:54:27 +09:00
irq genirq/msi: Make sure PCI MSIs are activated early 2016-08-09 09:19:32 +02:00
livepatch modules: add ro_after_init support 2016-08-04 10:16:55 +09:30
locking locking/pvqspinlock: Fix a bug in qstat_read() 2016-08-10 14:13:29 +02:00
power Merge branch 'pm-sleep' 2016-08-18 03:27:08 +02:00
printk Revert "printk: create pr_<level> functions" 2016-08-09 10:48:18 -07:00
rcu Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-07-29 13:55:30 -07:00
sched sched/cputime: Resync steal time when guest & host lose sync 2016-08-18 11:19:48 +02:00
time timekeeping: Cap array access in timekeeping_debug 2016-08-24 09:34:32 +02:00
trace block: rename bio bi_rw to bi_opf 2016-08-07 14:41:02 -06:00
.gitignore
acct.c
async.c
audit_fsnotify.c
audit_tree.c audit: cleanup prune_tree_thread 2016-04-04 09:46:47 -04:00
audit_watch.c don't bother with ->d_inode->i_sb - it's always equal to ->d_sb 2016-04-10 17:11:51 -04:00
audit.c Merge branch 'stable-4.8' of git://git.infradead.org/users/pcmoore/audit 2016-07-29 17:54:17 -07:00
audit.h Merge branch 'stable-4.8' of git://git.infradead.org/users/pcmoore/audit 2016-07-29 17:54:17 -07:00
auditfilter.c audit: add fields to exclude filter by reusing user filter 2016-06-27 11:01:00 -04:00
auditsc.c Merge branch 'stable-4.8' of git://git.infradead.org/users/pcmoore/audit 2016-07-29 17:54:17 -07:00
backtracetest.c
bounds.c
capability.c kernel: Add noaudit variant of ns_capable() 2016-06-06 20:16:18 +10:00
cgroup_freezer.c
cgroup_pids.c cgroup: Use lld instead of ld when printing pids controller events_limit 2016-06-21 15:03:36 -04:00
cgroup.c Merge branch 'for-4.7-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2016-07-29 14:29:04 -07:00
compat.c
configs.c
context_tracking.c
cpu_pm.c
cpu.c timers/core: Correct callback order during CPU hot plug 2016-07-28 18:56:22 +02:00
cpuset.c cpuset, mm: fix TIF_MEMDIE check in cpuset_change_task_nodemask 2016-07-28 16:07:41 -07:00
crash_dump.c
cred.c cred: Reject inodes with invalid ids in set_create_file_as() 2016-06-30 18:05:09 -05:00
delayacct.c
dma.c
elfcore.c
exec_domain.c
exit.c kernel/exit.c: quieten greatest stack depth printk 2016-08-02 19:35:23 -04:00
extable.c
fork.c mm: fix memcg stack accounting for sub-page stacks 2016-07-28 16:07:41 -07:00
freezer.c freezer, oom: check TIF_MEMDIE on the correct task 2016-07-28 16:07:41 -07:00
futex_compat.c
futex.c futex: Assume all mappings are private on !MMU systems 2016-07-29 18:44:14 +02:00
groups.c
hung_task.c kernel/hung_task.c: use timeout diff when timeout is updated 2016-03-22 15:36:02 -07:00
irq_work.c
jump_label.c powerpc updates for 4.8 #2 2016-08-05 09:00:54 -04:00
kallsyms.c kallsyms: add support for relative offsets in kallsyms address table 2016-03-15 16:55:16 -07:00
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c kernel/kcov: unproxify debugfs file's fops 2016-06-15 04:56:35 -07:00
kexec_core.c kexec: add restriction on kexec_load() segment sizes 2016-08-02 19:35:31 -04:00
kexec_file.c kexec: introduce a protection mechanism for the crashkernel reserved memory 2016-05-23 17:04:14 -07:00
kexec_internal.h
kexec.c kexec: allow architectures to override boot mapping 2016-08-02 19:35:27 -04:00
kmod.c
kprobes.c
ksysfs.c kexec: add a kexec_crash_loaded() function 2016-08-02 19:35:30 -04:00
kthread.c
latencytop.c
Makefile ELF/MIPS build fix 2016-05-23 17:04:14 -07:00
membarrier.c
memremap.c libnvdimm for 4.8 2016-07-28 17:38:16 -07:00
module_signing.c KEYS: Move the point of trust determination to __key_link() 2016-04-11 22:43:43 +01:00
module-internal.h
module.c Removed the MODULE_SIG_FORCE-means-no-MODULE_FORCE_LOAD patch. 2016-08-04 09:14:38 -04:00
notifier.c
nsproxy.c
padata.c kernel/padata.c: hide unused functions 2016-05-19 19:12:14 -07:00
panic.c kexec: use core_param for crash_kexec_post_notifiers boot option 2016-08-02 19:35:29 -04:00
params.c
pid_namespace.c
pid.c remove lots of IS_ERR_VALUE abuses 2016-05-27 15:26:11 -07:00
profile.c profile: Convert to hotplug state machine 2016-07-15 10:41:42 +02:00
ptrace.c tree-wide: replace config_enabled() with IS_ENABLED() 2016-08-04 08:50:07 -04:00
range.c
reboot.c
relay.c relay: add global mode support for buffer-only channels 2016-08-02 19:35:41 -04:00
resource.c /proc/iomem: only expose physical resource addresses to privileged users 2016-04-14 12:56:09 -07:00
seccomp.c tree-wide: replace config_enabled() with IS_ENABLED() 2016-08-04 08:50:07 -04:00
signal.c signals: Use hrtimer for sigtimedwait() 2016-07-07 10:35:07 +02:00
smp.c Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-07-29 13:55:30 -07:00
smpboot.c cpu/hotplug: Unpark smpboot threads from the state machine 2016-03-01 20:36:56 +01:00
smpboot.h cpu/hotplug: Create hotplug threads 2016-03-01 20:36:56 +01:00
softirq.c arch, ftrace: for KASAN put hard/soft IRQ entries into separate sections 2016-03-25 16:37:42 -07:00
stacktrace.c
stop_machine.c stop_machine: Touch_nmi_watchdog() after MULTI_STOP_PREPARE 2016-07-27 11:12:11 +02:00
sys_ni.c
sys.c prctl: make PR_SET_THP_DISABLE wait for mmap_sem killable 2016-05-23 17:04:14 -07:00
sysctl_binary.c kernel/sysctl_binary.c: use generic UUID library 2016-05-20 17:58:30 -07:00
sysctl.c printk: add kernel parameter to control writes to /dev/kmsg 2016-08-02 19:35:06 -04:00
task_work.c task_work: use READ_ONCE/lockless_dereference, avoid pi_lock if !task_works 2016-08-02 19:35:02 -04:00
taskstats.c taskstats: use the libnl API to align nlattr on 64-bit 2016-04-23 20:13:25 -04:00
test_kprobes.c
torture.c torture: Stop onoff task if there is only one cpu 2016-06-14 16:03:28 -07:00
tracepoint.c kernel/...: convert pr_warning to pr_warn 2016-03-22 15:36:02 -07:00
tsacct.c time, acct: Drop irq save & restore from __acct_update_integrals() 2016-02-29 09:53:09 +01:00
uid16.c
up.c
user_namespace.c fs: Limit file caps to the user namespace of the super block 2016-06-24 10:40:31 -05:00
user-return-notifier.c
user.c
utsname_sysctl.c
utsname.c
watchdog.c Revert "perf/x86/intel, watchdog: Switch NMI watchdog to ref cycles on x86" 2016-07-10 20:58:36 +02:00
workqueue_internal.h sched/core: Get rid of 'cpu' argument in wq_worker_sleeping() 2016-03-02 10:28:47 -05:00
workqueue.c Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-07-29 13:55:30 -07:00