Linus Torvalds 6b3a707736 Merge branch 'page-refs' (page ref overflow) ... Merge page ref overflow branch. Jann Horn reported that he can overflow the page ref count with sufficient memory (and a filesystem that is intentionally extremely slow). Admittedly it's not exactly easy. To have more than four billion references to a page requires a minimum of 32GB of kernel memory just for the pointers to the pages, much less any metadata to keep track of those pointers. Jann needed a total of 140GB of memory and a specially crafted filesystem that leaves all reads pending (in order to not ever free the page references and just keep adding more). Still, we have a fairly straightforward way to limit the two obvious user-controllable sources of page references: direct-IO like page references gotten through get_user_pages(), and the splice pipe page duplication. So let's just do that. * branch page-refs: fs: prevent page refcount overflow in pipe_buf_get mm: prevent get_user_pages() from overflowing page refcount mm: add 'try_get_page()' helper function mm: make page ref count overflow check tighter and more explicit		2019-04-14 15:09:40 -07:00
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bpf
cgroup
configs
debug
dma
events
gcov
irq
livepatch
locking
power
printk
rcu
sched
time
trace	Merge branch 'page-refs' (page ref overflow)	2019-04-14 15:09:40 -07:00
.gitignore
acct.c
async.c
audit_fsnotify.c
audit_tree.c
audit_watch.c
audit.c
audit.h
auditfilter.c
auditsc.c
backtracetest.c
bounds.c
capability.c
compat.c
configs.c
context_tracking.c
cpu_pm.c
cpu.c
crash_core.c
crash_dump.c
cred.c
delayacct.c
dma.c
elfcore.c
exec_domain.c
exit.c
extable.c
fail_function.c
fork.c
freezer.c
futex.c
groups.c
hung_task.c
iomem.c
irq_work.c
jump_label.c
kallsyms.c
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c
kexec_core.c
kexec_file.c
kexec_internal.h
kexec.c
kmod.c
kprobes.c
ksysfs.c
kthread.c
latencytop.c
Makefile
memremap.c
module_signing.c
module-internal.h
module.c
notifier.c
nsproxy.c
padata.c
panic.c
params.c
pid_namespace.c
pid.c
profile.c
ptrace.c
range.c
reboot.c
relay.c
resource.c
rseq.c
seccomp.c
signal.c
smp.c
smpboot.c
smpboot.h
softirq.c
stackleak.c
stacktrace.c
stop_machine.c
sys_ni.c
sys.c
sysctl_binary.c
sysctl.c
task_work.c
taskstats.c
test_kprobes.c
torture.c
tracepoint.c
tsacct.c
ucount.c
uid16.c
uid16.h
umh.c
up.c
user_namespace.c
user-return-notifier.c
user.c
utsname_sysctl.c
utsname.c
watchdog_hld.c
watchdog.c
workqueue_internal.h
workqueue.c