linux-stable/kernel
Christian Brauner 32a5ad9c22 sysctl: handle overflow for file-max
Currently, when writing

  echo 18446744073709551616 > /proc/sys/fs/file-max

/proc/sys/fs/file-max will overflow and be set to 0.  That quickly
crashes the system.

This commit sets the max and min value for file-max.  The max value is
set to long int.  Any higher value cannot currently be used as the
percpu counters are long ints and not unsigned integers.

Note that the file-max value is ultimately parsed via
__do_proc_doulongvec_minmax().  This function does not report error when
min or max are exceeded.  Which means if a value largen that long int is
written userspace will not receive an error instead the old value will be
kept.  There is an argument to be made that this should be changed and
__do_proc_doulongvec_minmax() should return an error when a dedicated min
or max value are exceeded.  However this has the potential to break
userspace so let's defer this to an RFC patch.

Link: http://lkml.kernel.org/r/20190107222700.15954-3-christian@brauner.io
Signed-off-by: Christian Brauner <christian@brauner.io>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Joe Lawrence <joe.lawrence@redhat.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Waiman Long <longman@redhat.com>
[christian@brauner.io: v4]
  Link: http://lkml.kernel.org/r/20190210203943.8227-3-christian@brauner.io
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-07 18:32:02 -08:00
..
bpf 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
cgroup kernel: cgroup: add poll file operation 2019-03-05 21:07:17 -08:00
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 swiotlb: clear io_tlb_start and io_tlb_end in swiotlb_exit 2019-01-16 09:59:17 -05:00
events perf/core improvements and fixes: 2019-02-28 08:29:50 +01:00
gcov
irq irqchip updates for Linux 5.1 2019-02-23 10:53:31 +01:00
livepatch livepatch: Replace synchronize_sched() with synchronize_rcu() 2018-12-01 12:38:50 -08:00
locking 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
power Power management updates for 5.1-rc1 2019-03-06 12:59:46 -08:00
printk Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
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 Merge branch 'akpm' (patches from Andrew) 2019-03-06 10:31:36 -08:00
time Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-03-05 14:49:11 -08:00
trace Merge branch 'linus' into perf/core, to pick up fixes 2019-02-28 08:27:17 +01:00
.gitignore
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 duplicated include from audit.c 2018-12-14 12:09:30 -05:00
audit.h audit: use current whenever possible 2018-11-26 18:41:21 -05:00
audit_fsnotify.c audit: minimize our use of audit_log_format() 2018-11-26 18:40:00 -05:00
audit_tree.c audit: minimize our use of audit_log_format() 2018-11-26 18:40:00 -05:00
audit_watch.c audit: minimize our use of audit_log_format() 2018-11-26 18:40:00 -05:00
auditfilter.c
auditsc.c audit: use current whenever possible 2018-11-26 18:41:21 -05:00
backtracetest.c
bounds.c kbuild: fix kernel/bounds.c 'W=1' warning 2018-10-31 08:54:14 -07:00
capability.c
compat.c time: make adjtime compat handling available for 32 bit 2019-02-07 00:13:27 +01:00
configs.c
context_tracking.c
cpu.c Linux 5.0-rc5 2019-02-04 08:57:24 +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 cred: export get_task_cred(). 2018-12-19 13:52:44 -05:00
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 kernel/exit.c: release ptraced tasks before zap_pid_ns_processes 2019-02-01 15:46:23 -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 sched/core: Convert task_struct.stack_refcount to refcount_t 2019-02-04 08:53:56 +01:00
freezer.c PM / reboot: Eliminate race between reboot and suspend 2018-08-06 12:35:20 +02:00
futex.c Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-03-06 07:17:17 -08:00
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
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
kcov.c kernel/kcov.c: mark write_comp_data() as notrace 2019-01-04 13:13:47 -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
Makefile kbuild: change filechk to surround the given command with { } 2019-01-06 09:46:51 +09:00
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 Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
range.c
reboot.c kernel/reboot.c: export pm_power_off_prepare 2018-09-11 16:13:24 +01:00
relay.c relay: check return of create_buf_file() properly 2019-01-31 14:01:48 +01:00
resource.c kernel, resource: check for IORESOURCE_SYSRAM in release_mem_region_adjustable 2018-12-28 12:11:49 -08:00
rseq.c Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
seccomp.c seccomp, bpf: disable preemption before calling into bpf prog 2019-02-22 00:14:19 +01:00
signal.c Merge branch 'timers-2038-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-03-05 14:08:26 -08:00
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 kernel/sys: annotate implicit fall through 2019-03-07 18:31:59 -08:00
sys_ni.c ipc: Fix building compat mode without sysvipc 2019-03-06 16:00:56 +01:00
sysctl.c sysctl: handle overflow for file-max 2019-03-07 18:32:02 -08:00
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: Mark watchdog touch functions as notrace 2018-08-30 12:56:40 +02:00
watchdog_hld.c watchdog: Mark watchdog touch functions as notrace 2018-08-30 12:56:40 +02:00
workqueue.c kernel: workqueue: clarify wq_worker_last_func() caller requirements 2019-03-07 18:32:01 -08:00
workqueue_internal.h psi: fix aggregation idle shut-off 2019-02-01 15:46:23 -08:00