linux-sg2042/kernel
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
..
bpf xdp: fix cpumap redirect SKB creation bug 2019-03-29 12:15:02 -07:00
cgroup Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-03-12 14:08:19 -07:00
configs kvm_config: add CONFIG_VIRTIO_MENU 2018-10-24 20:55:56 -04:00
debug kdb: use bool for binary state indicators 2018-12-30 08:31:52 +00:00
dma dma-debug: only skip one stackframe entry 2019-04-11 19:29:50 +02:00
events perf/core: Fix perf_event_disable_inatomic() race 2019-04-12 08:55:55 +02:00
gcov kernel/gcov/gcc_3_4.c: use struct_size() in kzalloc() 2019-03-07 18:32:02 -08:00
irq genirq: Respect IRQCHIP_SKIP_SET_WAKE in irq_chip_set_wake_parent() 2019-04-05 17:41:41 +02:00
livepatch Merge branch 'for-5.1/atomic-replace' into for-linus 2019-03-05 15:56:59 +01:00
locking locking/lockdep: Zap lock classes even with lock debugging disabled 2019-04-10 13:45:59 +02:00
power treewide: add checks for the return value of memblock_alloc*() 2019-03-12 10:04:02 -07:00
printk fbdev changes for v5.1: 2019-03-15 14:22:59 -07:00
rcu Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-03-06 07:59:36 -08:00
sched sched/fair: Do not re-read ->h_load_next during hierarchical load calculation 2019-04-03 09:50:22 +02:00
time alarmtimer: Return correct remaining time 2019-04-10 15:23:26 +02:00
trace Merge branch 'page-refs' (page ref overflow) 2019-04-14 15:09:40 -07:00
.gitignore kernel/configs: use .incbin directive to embed config_data.gz 2019-03-07 18:32:02 -08:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks bpf: introduce bpf_spin_lock 2019-02-01 20:55:38 +01:00
Kconfig.preempt kconfig: warn no new line at end of file 2018-12-15 17:44:35 +09:00
Makefile kernel/configs: use .incbin directive to embed config_data.gz 2019-03-07 18:32:02 -08:00
acct.c
async.c async: Add support for queueing on specific NUMA node 2019-01-31 14:20:54 +01:00
audit.c audit: remove audit_context when CONFIG_ AUDIT and not AUDITSYSCALL 2019-02-03 17:49:35 -05:00
audit.h audit: hide auditsc_get_stamp and audit_serial prototypes 2019-02-07 21:44:27 -05:00
audit_fsnotify.c audit: add syscall information to CONFIG_CHANGE records 2019-01-18 17:53:29 -05:00
audit_tree.c audit: hand taken context to audit_kill_trees for syscall logging 2019-01-14 18:01:05 -05:00
audit_watch.c audit: add syscall information to CONFIG_CHANGE records 2019-01-18 17:53:29 -05:00
auditfilter.c audit: mark expected switch fall-through 2019-02-12 20:17:13 -05:00
auditsc.c audit: remove audit_context when CONFIG_ AUDIT and not AUDITSYSCALL 2019-02-03 17:49:35 -05:00
backtracetest.c
bounds.c kbuild: fix kernel/bounds.c 'W=1' warning 2018-10-31 08:54:14 -07:00
capability.c LSM: add SafeSetID module that gates setid calls 2019-01-25 11:22:43 -08:00
compat.c time: make adjtime compat handling available for 32 bit 2019-02-07 00:13:27 +01:00
configs.c kernel/configs: use .incbin directive to embed config_data.gz 2019-03-07 18:32:02 -08:00
context_tracking.c
cpu.c cpu/hotplug: Prevent crash when CPU bringup fails on CONFIG_HOTPLUG_CPU=n 2019-03-28 13:34:58 +01:00
cpu_pm.c
crash_core.c kexec: export PG_offline to VMCOREINFO 2019-03-05 21:07:14 -08:00
crash_dump.c
cred.c SELinux: Remove cred security blob poisoning 2019-01-08 13:18:44 -08:00
delayacct.c delayacct: track delays from thrashing cache pages 2018-10-26 16:26:32 -07:00
dma.c
elfcore.c
exec_domain.c
exit.c Merge branch 'for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2019-03-07 10:11:41 -08:00
extable.c
fail_function.c kernel/fail_function.c: remove meaningless null pointer check before debugfs_remove_recursive 2018-10-31 08:54:12 -07:00
fork.c 5.1 Merge Window Pull Request 2019-03-09 15:53:03 -08:00
freezer.c PM / reboot: Eliminate race between reboot and suspend 2018-08-06 12:35:20 +02:00
futex.c futex: Ensure that futex address is aligned in handle_futex_death() 2019-03-22 13:05:26 +01:00
groups.c
hung_task.c kernel/hung_task.c: Use continuously blocked time when reporting. 2019-03-07 18:31:59 -08:00
iomem.c
irq_work.c
jump_label.c jump_label: move 'asm goto' support test to Kconfig 2019-01-06 09:46:51 +09:00
kallsyms.c bpf: Add module name [bpf] to ksymbols for bpf programs 2019-01-21 17:38:56 -03:00
kcmp.c
kcov.c kcov: convert kcov.refcount to refcount_t 2019-03-07 18:32:02 -08:00
kexec.c kexec: add call to LSM hook in original kexec_load syscall 2018-07-16 12:31:57 -07:00
kexec_core.c mm: convert totalram_pages and totalhigh_pages variables to atomic 2018-12-28 12:11:47 -08:00
kexec_file.c kexec_file: kexec_walk_memblock() only walks a dedicated region at kdump 2018-12-06 14:38:50 +00:00
kexec_internal.h
kmod.c
kprobes.c kprobes: Search non-suffixed symbol in blacklist 2019-02-13 08:16:40 +01:00
ksysfs.c
kthread.c Merge branch 'akpm' (patches from Andrew) 2019-03-06 10:31:36 -08:00
latencytop.c
memremap.c mm/hmm: fix memremap.h, move dev_page_fault_t callback to hmm 2018-12-28 12:11:52 -08:00
module-internal.h
module.c dynamic_debug: add static inline stub for ddebug_add_module 2019-03-07 18:32:00 -08:00
module_signing.c modsign: use all trusted keys to verify module signature 2018-11-07 14:41:41 +01:00
notifier.c
nsproxy.c
padata.c padata: clean an indentation issue, remove extraneous space 2018-11-16 14:11:04 +08:00
panic.c kernel/panic.c: taint: fix debugfs_simple_attr.cocci warnings 2019-03-07 18:31:59 -08:00
params.c
pid.c Fix failure path in alloc_pid() 2018-12-28 12:42:30 -08:00
pid_namespace.c signal: Use group_send_sig_info to kill all processes in a pid namespace 2018-09-16 16:08:25 +02:00
profile.c mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
ptrace.c ptrace: take into account saved_sigmask in PTRACE{GET,SET}SIGMASK 2019-03-29 10:01:37 -07:00
range.c
reboot.c kernel/reboot.c: export pm_power_off_prepare 2018-09-11 16:13:24 +01:00
relay.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-03-12 13:27:20 -07:00
resource.c device-dax for 5.1 2019-03-16 13:05:32 -07:00
rseq.c Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
seccomp.c syscalls: Remove start and number from syscall_get_arguments() args 2019-04-05 09:26:43 -04:00
signal.c signal: don't silently convert SI_USER signals to non-current pidfd 2019-04-01 23:03:18 +02:00
smp.c cpu/hotplug: Fix "SMT disabled by BIOS" detection for KVM 2019-01-30 19:27:00 +01:00
smpboot.c
smpboot.h
softirq.c softirq: Don't skip softirq execution when softirq thread is parking 2019-02-10 21:51:39 +01:00
stackleak.c stackleak: Mark stackleak_track_stack() as notrace 2018-12-05 19:31:44 -08:00
stacktrace.c
stop_machine.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-08-13 11:25:07 -07:00
sys.c Merge branch 'akpm' (patches from Andrew) 2019-03-07 19:25:37 -08:00
sys_ni.c pidfd patches for v5.1-rc1 2019-03-16 13:47:14 -07:00
sysctl.c kernel/sysctl.c: fix out-of-bounds access when setting file-max 2019-04-05 16:02:31 -10:00
sysctl_binary.c kernel/sysctl: add panic_print into sysctl 2019-01-04 13:13:47 -08:00
task_work.c
taskstats.c
test_kprobes.c
torture.c Merge branches 'doc.2019.01.26a', 'fixes.2019.01.26a', 'sil.2019.01.26a', 'spdx.2019.02.09a', 'srcu.2019.01.26a' and 'torture.2019.01.26a' into HEAD 2019-02-09 08:47:52 -08:00
tracepoint.c tracing: Replace synchronize_sched() and call_rcu_sched() 2018-11-27 09:21:41 -08:00
tsacct.c
ucount.c
uid16.c
uid16.h
umh.c umh: add exit routine for UMH process 2019-01-11 18:05:40 -08:00
up.c smp,cpumask: introduce on_each_cpu_cond_mask 2018-10-09 16:51:11 +02:00
user-return-notifier.c
user.c userns: use irqsave variant of refcount_dec_and_lock() 2018-08-22 10:52:47 -07:00
user_namespace.c userns: also map extents in the reverse map to kernel IDs 2018-11-07 23:51:16 -06:00
utsname.c
utsname_sysctl.c sys: don't hold uts_sem while accessing userspace memory 2018-08-11 02:05:53 -05:00
watchdog.c watchdog: Respect watchdog cpumask on CPU hotplug 2019-03-28 13:32:01 +01:00
watchdog_hld.c watchdog: Mark watchdog touch functions as notrace 2018-08-30 12:56:40 +02:00
workqueue.c workqueue: Only unregister a registered lockdep key 2019-03-21 12:00:18 +01:00
workqueue_internal.h psi: fix aggregation idle shut-off 2019-02-01 15:46:23 -08:00