commit bce9332220 upstream.
proc_skip_spaces() seems to think it is working on C strings, and ends
up being just a wrapper around skip_spaces() with a really odd calling
convention.
Instead of basing it on skip_spaces(), it should have looked more like
proc_skip_char(), which really is the exact same function (except it
skips a particular character, rather than whitespace). So use that as
inspiration, odd coding and all.
Now the calling convention actually makes sense and works for the
intended purpose.
Reported-and-tested-by: Kyle Zeng <zengyhkyle@gmail.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e6cfaf34be upstream.
proc_get_long() is passed a size_t, but then assigns it to an 'int'
variable for the length. Let's not do that, even if our IO paths are
limited to MAX_RW_COUNT (exactly because of these kinds of type errors).
So do the proper test in the rigth type.
Reported-by: Kyle Zeng <zengyhkyle@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 44a3918c82 upstream.
With unprivileged eBPF enabled, eIBRS (without retpoline) is vulnerable
to Spectre v2 BHB-based attacks.
When both are enabled, print a warning message and report it in the
'spectre_v2' sysfs vulnerabilities file.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
[fllinden@amazon.com: backported to 4.14]
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 08389d8882 upstream.
Add a kconfig knob which allows for unprivileged bpf to be disabled by default.
If set, the knob sets /proc/sys/kernel/unprivileged_bpf_disabled to value of 2.
This still allows a transition of 2 -> {0,1} through an admin. Similarly,
this also still keeps 1 -> {1} behavior intact, so that once set to permanently
disabled, it cannot be undone aside from a reboot.
We've also added extra2 with max of 2 for the procfs handler, so that an admin
still has a chance to toggle between 0 <-> 2.
Either way, as an additional alternative, applications can make use of CAP_BPF
that we added a while ago.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/74ec548079189e4e4dffaeb42b8987bb3c852eee.1620765074.git.daniel@iogearbox.net
[fllinden@amazon.com: backported to 4.14]
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 204cb79ad4 ]
Currently, the drop_caches proc file and sysctl read back the last value
written, suggesting this is somehow a stateful setting instead of a
one-time command. Make it write-only, like e.g. compact_memory.
While mitigating a VM problem at scale in our fleet, there was confusion
about whether writing to this file will permanently switch the kernel into
a non-caching mode. This influences the decision making in a tense
situation, where tens of people are trying to fix tens of thousands of
affected machines: Do we need a rollback strategy? What are the
performance implications of operating in a non-caching state for several
days? It also caused confusion when the kernel team said we may need to
write the file several times to make sure it's effective ("But it already
reads back 3?").
Link: http://lkml.kernel.org/r/20191031221602.9375-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Chris Down <chris@chrisdown.name>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e260ad01f0 ]
Currently when userspace gives us a values that overflow e.g. file-max
and other callers of __do_proc_doulongvec_minmax() we simply ignore the
new value and leave the current value untouched.
This can be problematic as it gives the illusion that the limit has
indeed be bumped when in fact it failed. This commit makes sure to
return EINVAL when an overflow is detected. Please note that this is a
userspace facing change.
Link: http://lkml.kernel.org/r/20190210203943.8227-4-christian@brauner.io
Signed-off-by: Christian Brauner <christian@brauner.io>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: 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: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 9002b21465 upstream.
Commit 32a5ad9c22 ("sysctl: handle overflow for file-max") hooked up
min/max values for the file-max sysctl parameter via the .extra1 and
.extra2 fields in the corresponding struct ctl_table entry.
Unfortunately, the minimum value points at the global 'zero' variable,
which is an int. This results in a KASAN splat when accessed as a long
by proc_doulongvec_minmax on 64-bit architectures:
| BUG: KASAN: global-out-of-bounds in __do_proc_doulongvec_minmax+0x5d8/0x6a0
| Read of size 8 at addr ffff2000133d1c20 by task systemd/1
|
| CPU: 0 PID: 1 Comm: systemd Not tainted 5.1.0-rc3-00012-g40b114779944 #2
| Hardware name: linux,dummy-virt (DT)
| Call trace:
| dump_backtrace+0x0/0x228
| show_stack+0x14/0x20
| dump_stack+0xe8/0x124
| print_address_description+0x60/0x258
| kasan_report+0x140/0x1a0
| __asan_report_load8_noabort+0x18/0x20
| __do_proc_doulongvec_minmax+0x5d8/0x6a0
| proc_doulongvec_minmax+0x4c/0x78
| proc_sys_call_handler.isra.19+0x144/0x1d8
| proc_sys_write+0x34/0x58
| __vfs_write+0x54/0xe8
| vfs_write+0x124/0x3c0
| ksys_write+0xbc/0x168
| __arm64_sys_write+0x68/0x98
| el0_svc_common+0x100/0x258
| el0_svc_handler+0x48/0xc0
| el0_svc+0x8/0xc
|
| The buggy address belongs to the variable:
| zero+0x0/0x40
|
| Memory state around the buggy address:
| ffff2000133d1b00: 00 00 00 00 00 00 00 00 fa fa fa fa 04 fa fa fa
| ffff2000133d1b80: fa fa fa fa 04 fa fa fa fa fa fa fa 04 fa fa fa
| >ffff2000133d1c00: fa fa fa fa 04 fa fa fa fa fa fa fa 00 00 00 00
| ^
| ffff2000133d1c80: fa fa fa fa 00 fa fa fa fa fa fa fa 00 00 00 00
| ffff2000133d1d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
Fix the splat by introducing a unsigned long 'zero_ul' and using that
instead.
Link: http://lkml.kernel.org/r/20190403153409.17307-1-will.deacon@arm.com
Fixes: 32a5ad9c22 ("sysctl: handle overflow for file-max")
Signed-off-by: Will Deacon <will.deacon@arm.com>
Acked-by: Christian Brauner <christian@brauner.io>
Cc: Kees Cook <keescook@chromium.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Matteo Croce <mcroce@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 32a5ad9c22 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 8cf7630b29 upstream.
This bug has apparently existed since the introduction of this function
in the pre-git era (4500e91754d3 in Thomas Gleixner's history.git,
"[NET]: Add proc_dointvec_userhz_jiffies, use it for proper handling of
neighbour sysctls.").
As a minimal fix we can simply duplicate the corresponding check in
do_proc_dointvec_conv().
Link: http://lkml.kernel.org/r/20190207123426.9202-3-zev@bewilderbeest.net
Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: <stable@vger.kernel.org> [2.6.2+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 09be178400 ]
If the number of input parameters is less than the total parameters, an
EINVAL error will be returned.
For example, we use proc_doulongvec_minmax to pass up to two parameters
with kern_table:
{
.procname = "monitor_signals",
.data = &monitor_sigs,
.maxlen = 2*sizeof(unsigned long),
.mode = 0644,
.proc_handler = proc_doulongvec_minmax,
},
Reproduce:
When passing two parameters, it's work normal. But passing only one
parameter, an error "Invalid argument"(EINVAL) is returned.
[root@cl150 ~]# echo 1 2 > /proc/sys/kernel/monitor_signals
[root@cl150 ~]# cat /proc/sys/kernel/monitor_signals
1 2
[root@cl150 ~]# echo 3 > /proc/sys/kernel/monitor_signals
-bash: echo: write error: Invalid argument
[root@cl150 ~]# echo $?
1
[root@cl150 ~]# cat /proc/sys/kernel/monitor_signals
3 2
[root@cl150 ~]#
The following is the result after apply this patch. No error is
returned when the number of input parameters is less than the total
parameters.
[root@cl150 ~]# echo 1 2 > /proc/sys/kernel/monitor_signals
[root@cl150 ~]# cat /proc/sys/kernel/monitor_signals
1 2
[root@cl150 ~]# echo 3 > /proc/sys/kernel/monitor_signals
[root@cl150 ~]# echo $?
0
[root@cl150 ~]# cat /proc/sys/kernel/monitor_signals
3 2
[root@cl150 ~]#
There are three processing functions dealing with digital parameters,
__do_proc_dointvec/__do_proc_douintvec/__do_proc_doulongvec_minmax.
This patch deals with __do_proc_doulongvec_minmax, just as
__do_proc_dointvec does, adding a check for parameters 'left'. In
__do_proc_douintvec, its code implementation explicitly does not support
multiple inputs.
static int __do_proc_douintvec(...){
...
/*
* Arrays are not supported, keep this simple. *Do not* add
* support for them.
*/
if (vleft != 1) {
*lenp = 0;
return -EINVAL;
}
...
}
So, just __do_proc_doulongvec_minmax has the problem. And most use of
proc_doulongvec_minmax/proc_doulongvec_ms_jiffies_minmax just have one
parameter.
Link: http://lkml.kernel.org/r/1544081775-15720-1-git-send-email-cheng.lin130@zte.com.cn
Signed-off-by: Cheng Lin <cheng.lin130@zte.com.cn>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 30aba6656f upstream.
Disallows open of FIFOs or regular files not owned by the user in world
writable sticky directories, unless the owner is the same as that of the
directory or the file is opened without the O_CREAT flag. The purpose
is to make data spoofing attacks harder. This protection can be turned
on and off separately for FIFOs and regular files via sysctl, just like
the symlinks/hardlinks protection. This patch is based on Openwall's
"HARDEN_FIFO" feature by Solar Designer.
This is a brief list of old vulnerabilities that could have been prevented
by this feature, some of them even allow for privilege escalation:
CVE-2000-1134
CVE-2007-3852
CVE-2008-0525
CVE-2009-0416
CVE-2011-4834
CVE-2015-1838
CVE-2015-7442
CVE-2016-7489
This list is not meant to be complete. It's difficult to track down all
vulnerabilities of this kind because they were often reported without any
mention of this particular attack vector. In fact, before
hardlinks/symlinks restrictions, fifos/regular files weren't the favorite
vehicle to exploit them.
[s.mesoraca16@gmail.com: fix bug reported by Dan Carpenter]
Link: https://lkml.kernel.org/r/20180426081456.GA7060@mwanda
Link: http://lkml.kernel.org/r/1524829819-11275-1-git-send-email-s.mesoraca16@gmail.com
[keescook@chromium.org: drop pr_warn_ratelimited() in favor of audit changes in the future]
[keescook@chromium.org: adjust commit subjet]
Link: http://lkml.kernel.org/r/20180416175918.GA13494@beast
Signed-off-by: Salvatore Mesoraca <s.mesoraca16@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Suggested-by: Solar Designer <solar@openwall.com>
Suggested-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Loic <hackurx@opensec.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 98159d977f ]
Patch series "A few round_pipe_size() and pipe-max-size fixups", v3.
While backporting Michael's "pipe: fix limit handling" patchset to a
distro-kernel, Mikulas noticed that current upstream pipe limit handling
contains a few problems:
1 - procfs signed wrap: echo'ing a large number into
/proc/sys/fs/pipe-max-size and then cat'ing it back out shows a
negative value.
2 - round_pipe_size() nr_pages overflow on 32bit: this would
subsequently try roundup_pow_of_two(0), which is undefined.
3 - visible non-rounded pipe-max-size value: there is no mutual
exclusion or protection between the time pipe_max_size is assigned
a raw value from proc_dointvec_minmax() and when it is rounded.
4 - unsigned long -> unsigned int conversion makes for potential odd
return errors from do_proc_douintvec_minmax_conv() and
do_proc_dopipe_max_size_conv().
This version underwent the same testing as v1:
https://marc.info/?l=linux-kernel&m=150643571406022&w=2
This patch (of 4):
pipe_max_size is defined as an unsigned int:
unsigned int pipe_max_size = 1048576;
but its procfs/sysctl representation is an integer:
static struct ctl_table fs_table[] = {
...
{
.procname = "pipe-max-size",
.data = &pipe_max_size,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &pipe_proc_fn,
.extra1 = &pipe_min_size,
},
...
that is signed:
int pipe_proc_fn(struct ctl_table *table, int write, void __user *buf,
size_t *lenp, loff_t *ppos)
{
...
ret = proc_dointvec_minmax(table, write, buf, lenp, ppos)
This leads to signed results via procfs for large values of pipe_max_size:
% echo 2147483647 >/proc/sys/fs/pipe-max-size
% cat /proc/sys/fs/pipe-max-size
-2147483648
Use unsigned operations on this variable to avoid such negative values.
Link: http://lkml.kernel.org/r/1507658689-11669-2-git-send-email-joe.lawrence@redhat.com
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull watchddog clean-up and fixes from Thomas Gleixner:
"The watchdog (hard/softlockup detector) code is pretty much broken in
its current state. The patch series addresses this by removing all
duct tape and refactoring it into a workable state.
The reasons why I ask for inclusion that late in the cycle are:
1) The code causes lockdep splats vs. hotplug locking which get
reported over and over. Unfortunately there is no easy fix.
2) The risk of breakage is minimal because it's already broken
3) As 4.14 is a long term stable kernel, I prefer to have working
watchdog code in that and the lockdep issues resolved. I wouldn't
ask you to pull if 4.14 wouldn't be a LTS kernel or if the
solution would be easy to backport.
4) The series was around before the merge window opened, but then got
delayed due to the UP failure caused by the for_each_cpu()
surprise which we discussed recently.
Changes vs. V1:
- Addressed your review points
- Addressed the warning in the powerpc code which was discovered late
- Changed two function names which made sense up to a certain point
in the series. Now they match what they do in the end.
- Fixed a 'unused variable' warning, which got not detected by the
intel robot. I triggered it when trying all possible related config
combinations manually. Randconfig testing seems not random enough.
The changes have been tested by and reviewed by Don Zickus and tested
and acked by Micheal Ellerman for powerpc"
* 'core-watchdog-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits)
watchdog/core: Put softlockup_threads_initialized under ifdef guard
watchdog/core: Rename some softlockup_* functions
powerpc/watchdog: Make use of watchdog_nmi_probe()
watchdog/core, powerpc: Lock cpus across reconfiguration
watchdog/core, powerpc: Replace watchdog_nmi_reconfigure()
watchdog/hardlockup/perf: Fix spelling mistake: "permanetely" -> "permanently"
watchdog/hardlockup/perf: Cure UP damage
watchdog/hardlockup: Clean up hotplug locking mess
watchdog/hardlockup/perf: Simplify deferred event destroy
watchdog/hardlockup/perf: Use new perf CPU enable mechanism
watchdog/hardlockup/perf: Implement CPU enable replacement
watchdog/hardlockup/perf: Implement init time detection of perf
watchdog/hardlockup/perf: Implement init time perf validation
watchdog/core: Get rid of the racy update loop
watchdog/core, powerpc: Make watchdog_nmi_reconfigure() two stage
watchdog/sysctl: Clean up sysctl variable name space
watchdog/sysctl: Get rid of the #ifdeffery
watchdog/core: Clean up header mess
watchdog/core: Further simplify sysctl handling
watchdog/core: Get rid of the thread teardown/setup dance
...
do_proc_douintvec_conv() has two UINT_MAX checks, we can remove one.
This has no functional changes other than fixing a compiler warning:
kernel/sysctl.c:2190]: (warning) Identical condition '*lvalp>UINT_MAX', second condition is always false
Fixes: 4f2fec00af ("sysctl: simplify unsigned int support")
Link: http://lkml.kernel.org/r/20170919072918.12066-1-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Reported-by: David Binderman <dcb314@hotmail.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Reflect that these variables are user interface related and remove the
whitespace damage in the sysctl table while at it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Don Zickus <dzickus@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Link: http://lkml.kernel.org/r/20170912194147.783210221@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The sysctl of the nmi_watchdog file prevents writes by setting:
min = max = 0
if none of the users is enabled. That involves ifdeffery and is competely
non obvious.
If none of the facilities is enabeld, then the file can simply be made read
only. Move the ifdeffery into the header and use a constant for file
permissions.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Don Zickus <dzickus@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Link: http://lkml.kernel.org/r/20170912194147.706073616@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Split SOFTLOCKUP_DETECTOR from LOCKUP_DETECTOR, and split
HARDLOCKUP_DETECTOR_PERF from HARDLOCKUP_DETECTOR.
LOCKUP_DETECTOR implies the general boot, sysctl, and programming
interfaces for the lockup detectors.
An architecture that wants to use a hard lockup detector must define
HAVE_HARDLOCKUP_DETECTOR_PERF or HAVE_HARDLOCKUP_DETECTOR_ARCH.
Alternatively an arch can define HAVE_NMI_WATCHDOG, which provides the
minimum arch_touch_nmi_watchdog, and it otherwise does its own thing and
does not implement the LOCKUP_DETECTOR interfaces.
sparc is unusual in that it has started to implement some of the
interfaces, but not fully yet. It should probably be converted to a full
HAVE_HARDLOCKUP_DETECTOR_ARCH.
[npiggin@gmail.com: fix]
Link: http://lkml.kernel.org/r/20170617223522.66c0ad88@roar.ozlabs.ibm.com
Link: http://lkml.kernel.org/r/20170616065715.18390-4-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Don Zickus <dzickus@redhat.com>
Reviewed-by: Babu Moger <babu.moger@oracle.com>
Tested-by: Babu Moger <babu.moger@oracle.com> [sparc]
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
To keep parity with regular int interfaces provide the an unsigned int
proc_douintvec_minmax() which allows you to specify a range of allowed
valid numbers.
Adding proc_douintvec_minmax_sysadmin() is easy but we can wait for an
actual user for that.
Link: http://lkml.kernel.org/r/20170519033554.18592-6-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit e7d316a02f ("sysctl: handle error writing UINT_MAX to u32
fields") added proc_douintvec() to start help adding support for
unsigned int, this however was only half the work needed. Two fixes
have come in since then for the following issues:
o Printing the values shows a negative value, this happens since
do_proc_dointvec() and this uses proc_put_long()
This was fixed by commit 5380e5644a ("sysctl: don't print negative
flag for proc_douintvec").
o We can easily wrap around the int values: UINT_MAX is 4294967295, if
we echo in 4294967295 + 1 we end up with 0, using 4294967295 + 2 we
end up with 1.
o We echo negative values in and they are accepted
This was fixed by commit 425fffd886 ("sysctl: report EINVAL if value
is larger than UINT_MAX for proc_douintvec").
It still also failed to be added to sysctl_check_table()... instead of
adding it with the current implementation just provide a proper and
simplified unsigned int support without any array unsigned int support
with no negative support at all.
Historically sysctl proc helpers have supported arrays, due to the
complexity this adds though we've taken a step back to evaluate array
users to determine if its worth upkeeping for unsigned int. An
evaluation using Coccinelle has been done to perform a grammatical
search to ask ourselves:
o How many sysctl proc_dointvec() (int) users exist which likely
should be moved over to proc_douintvec() (unsigned int) ?
Answer: about 8
- Of these how many are array users ?
Answer: Probably only 1
o How many sysctl array users exist ?
Answer: about 12
This last question gives us an idea just how popular arrays: they are not.
Array support should probably just be kept for strings.
The identified uint ports are:
drivers/infiniband/core/ucma.c - max_backlog
drivers/infiniband/core/iwcm.c - default_backlog
net/core/sysctl_net_core.c - rps_sock_flow_sysctl()
net/netfilter/nf_conntrack_timestamp.c - nf_conntrack_timestamp -- bool
net/netfilter/nf_conntrack_acct.c nf_conntrack_acct -- bool
net/netfilter/nf_conntrack_ecache.c - nf_conntrack_events -- bool
net/netfilter/nf_conntrack_helper.c - nf_conntrack_helper -- bool
net/phonet/sysctl.c proc_local_port_range()
The only possible array users is proc_local_port_range() but it does not
seem worth it to add array support just for this given the range support
works just as well. Unsigned int support should be desirable more for
when you *need* more than INT_MAX or using int min/max support then does
not suffice for your ranges.
If you forget and by mistake happen to register an unsigned int proc
entry with an array, the driver will fail and you will get something as
follows:
sysctl table check failed: debug/test_sysctl//uint_0002 array now allowed
CPU: 2 PID: 1342 Comm: modprobe Tainted: G W E <etc>
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS <etc>
Call Trace:
dump_stack+0x63/0x81
__register_sysctl_table+0x350/0x650
? kmem_cache_alloc_trace+0x107/0x240
__register_sysctl_paths+0x1b3/0x1e0
? 0xffffffffc005f000
register_sysctl_table+0x1f/0x30
test_sysctl_init+0x10/0x1000 [test_sysctl]
do_one_initcall+0x52/0x1a0
? kmem_cache_alloc_trace+0x107/0x240
do_init_module+0x5f/0x200
load_module+0x1867/0x1bd0
? __symbol_put+0x60/0x60
SYSC_finit_module+0xdf/0x110
SyS_finit_module+0xe/0x10
entry_SYSCALL_64_fastpath+0x1e/0xad
RIP: 0033:0x7f042b22d119
<etc>
Fixes: e7d316a02f ("sysctl: handle error writing UINT_MAX to u32 fields")
Link: http://lkml.kernel.org/r/20170519033554.18592-5-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Suggested-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Cc: Liping Zhang <zlpnobody@gmail.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The mode sysctl_writes_strict positional checks keep being copy and pasted
as we add new proc handlers. Just add a helper to avoid code duplication.
Link: http://lkml.kernel.org/r/20170519033554.18592-4-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Suggested-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Document the different sysctl_writes_strict modes in code.
Link: http://lkml.kernel.org/r/20170519033554.18592-3-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
do_proc_dointvec_jiffies_conv() uses LONG_MAX/HZ as the max value to
avoid overflow. But actually the *valp is int type, so it still causes
overflow.
For example,
echo 2147483647 > ./sys/net/ipv4/tcp_keepalive_time
Then,
cat ./sys/net/ipv4/tcp_keepalive_time
The output is "-1", it is not expected.
Now use INT_MAX/HZ as the max value instead LONG_MAX/HZ to fix it.
Link: http://lkml.kernel.org/r/1490109532-9228-1-git-send-email-fgao@ikuai8.com
Signed-off-by: Gao Feng <fgao@ikuai8.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull timer updates from Thomas Gleixner:
"The timer departement delivers:
- more year 2038 rework
- a massive rework of the arm achitected timer
- preparatory patches to allow NTP correction of clock event devices
to avoid early expiry
- the usual pile of fixes and enhancements all over the place"
* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (91 commits)
timer/sysclt: Restrict timer migration sysctl values to 0 and 1
arm64/arch_timer: Mark errata handlers as __maybe_unused
Clocksource/mips-gic: Remove redundant non devicetree init
MIPS/Malta: Probe gic-timer via devicetree
clocksource: Use GENMASK_ULL in definition of CLOCKSOURCE_MASK
acpi/arm64: Add SBSA Generic Watchdog support in GTDT driver
clocksource: arm_arch_timer: add GTDT support for memory-mapped timer
acpi/arm64: Add memory-mapped timer support in GTDT driver
clocksource: arm_arch_timer: simplify ACPI support code.
acpi/arm64: Add GTDT table parse driver
clocksource: arm_arch_timer: split MMIO timer probing.
clocksource: arm_arch_timer: add structs to describe MMIO timer
clocksource: arm_arch_timer: move arch_timer_needs_of_probing into DT init call
clocksource: arm_arch_timer: refactor arch_timer_needs_probing
clocksource: arm_arch_timer: split dt-only rate handling
x86/uv/time: Set ->min_delta_ticks and ->max_delta_ticks
unicore32/time: Set ->min_delta_ticks and ->max_delta_ticks
um/time: Set ->min_delta_ticks and ->max_delta_ticks
tile/time: Set ->min_delta_ticks and ->max_delta_ticks
score/time: Set ->min_delta_ticks and ->max_delta_ticks
...
timer_migration sysctl acts as a boolean switch, so the allowed values
should be restricted to 0 and 1.
Add the necessary extra fields to the sysctl table entry to enforce that.
[ tglx: Rewrote changelog ]
Signed-off-by: Myungho Jung <mhjungk@gmail.com>
Link: http://lkml.kernel.org/r/1492640690-3550-1-git-send-email-mhjungk@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Currently, inputting the following command will succeed but actually the
value will be truncated:
# echo 0x12ffffffff > /proc/sys/net/ipv4/tcp_notsent_lowat
This is not friendly to the user, so instead, we should report error
when the value is larger than UINT_MAX.
Fixes: e7d316a02f ("sysctl: handle error writing UINT_MAX to u32 fields")
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Cc: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I saw some very confusing sysctl output on my system:
# cat /proc/sys/net/core/xfrm_aevent_rseqth
-2
# cat /proc/sys/net/core/xfrm_aevent_etime
-10
# cat /proc/sys/net/ipv4/tcp_notsent_lowat
-4294967295
Because we forget to set the *negp flag in proc_douintvec, so it will
become a garbage value.
Since the value related to proc_douintvec is always an unsigned integer,
so we can set *negp to false explictily to fix this issue.
Fixes: e7d316a02f ("sysctl: handle error writing UINT_MAX to u32 fields")
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Cc: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We are going to split <linux/sched/coredump.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.
Create a trivial placeholder <linux/sched/coredump.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.
Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We added the 'sched_rr_timeslice_ms' SCHED_RR tuning knob in this commit:
ce0dbbbb30 ("sched/rt: Add a tuning knob to allow changing SCHED_RR timeslice")
... which name suggests to users that it's in milliseconds, while in reality
it's being set in milliseconds but the result is shown in jiffies.
This is obviously confusing when HZ is not 1000, it makes it appear like the
value set failed, such as HZ=100:
root# echo 100 > /proc/sys/kernel/sched_rr_timeslice_ms
root# cat /proc/sys/kernel/sched_rr_timeslice_ms
10
Fix this to be milliseconds all around.
Signed-off-by: Shile Zhang <shile.zhang@nokia.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1485612049-20923-1-git-send-email-shile.zhang@nokia.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We perform the conversion between kernel jiffies and ms only when
exporting kernel value to user space.
We need to do the opposite operation when value is written by user.
Only matters when HZ != 1000
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This was entirely automated, using the script by Al:
PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
$(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)
to do the replacement at the end of the merge window.
Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
o STM can hook into the function tracer
o Function filtering now supports more advance glob matching
o Ftrace selftests updates and added tests
o Softirq tag in traces now show only softirqs
o ARM nop added to non traced locations at compile time
o New trace_marker_raw file that allows for binary input
o Optimizations to the ring buffer
o Removal of kmap in trace_marker
o Wakeup and irqsoff tracers now adhere to the set_graph_notrace file
o Other various fixes and clean ups
Note, there are two patches marked for stable. These were discovered
near the end of the 4.9 rc release cycle. By the time I had them tested
it was just a matter of days before 4.9 would be released, and I
figured I would just submit them in the merge window. They are old
bugs and not critical. Nothing non-root could abuse.
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Merge tag 'trace-v4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
"This release has a few updates:
- STM can hook into the function tracer
- Function filtering now supports more advance glob matching
- Ftrace selftests updates and added tests
- Softirq tag in traces now show only softirqs
- ARM nop added to non traced locations at compile time
- New trace_marker_raw file that allows for binary input
- Optimizations to the ring buffer
- Removal of kmap in trace_marker
- Wakeup and irqsoff tracers now adhere to the set_graph_notrace file
- Other various fixes and clean ups"
* tag 'trace-v4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (42 commits)
selftests: ftrace: Shift down default message verbosity
kprobes/trace: Fix kprobe selftest for newer gcc
tracing/kprobes: Add a helper method to return number of probe hits
tracing/rb: Init the CPU mask on allocation
tracing: Use SOFTIRQ_OFFSET for softirq dectection for more accurate results
tracing/fgraph: Have wakeup and irqsoff tracers ignore graph functions too
fgraph: Handle a case where a tracer ignores set_graph_notrace
tracing: Replace kmap with copy_from_user() in trace_marker writing
ftrace/x86_32: Set ftrace_stub to weak to prevent gcc from using short jumps to it
tracing: Allow benchmark to be enabled at early_initcall()
tracing: Have system enable return error if one of the events fail
tracing: Do not start benchmark on boot up
tracing: Have the reg function allow to fail
ring-buffer: Force rb_end_commit() and rb_set_commit_to_write() inline
ring-buffer: Froce rb_update_write_stamp() to be inlined
ring-buffer: Force inline of hotpath helper functions
tracing: Make __buffer_unlock_commit() always_inline
tracing: Make tracepoint_printk a static_key
ring-buffer: Always inline rb_event_data()
ring-buffer: Make rb_reserve_next_event() always inlined
...
I was amused to find "unsafe core_pattern" warning having these lines in
/etc/sysctl.conf:
fs.suid_dumpable=2
kernel.core_pattern=/core/core-%e-%p-%E
kernel.core_uses_pid=0
Turns out kernel is formally right. Default core_pattern is just "core",
which doesn't qualify for secure path while setting suid.dumpable.
Hint admins about solution, clarify sysctl names, delete unnecessary '\'
characters (string literals are concatenated regardless) and reformat for
easier grepping.
Link: http://lkml.kernel.org/r/20161029152124.GA1258@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull x86 asm updates from Ingo Molnar:
"The main changes in this development cycle were:
- a large number of call stack dumping/printing improvements: higher
robustness, better cross-context dumping, improved output, etc.
(Josh Poimboeuf)
- vDSO getcpu() performance improvement for future Intel CPUs with
the RDPID instruction (Andy Lutomirski)
- add two new Intel AVX512 features and the CPUID support
infrastructure for it: AVX512IFMA and AVX512VBMI. (Gayatri Kammela,
He Chen)
- more copy-user unification (Borislav Petkov)
- entry code assembly macro simplifications (Alexander Kuleshov)
- vDSO C/R support improvements (Dmitry Safonov)
- misc fixes and cleanups (Borislav Petkov, Paul Bolle)"
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits)
scripts/decode_stacktrace.sh: Fix address line detection on x86
x86/boot/64: Use defines for page size
x86/dumpstack: Make stack name tags more comprehensible
selftests/x86: Add test_vdso to test getcpu()
x86/vdso: Use RDPID in preference to LSL when available
x86/dumpstack: Handle NULL stack pointer in show_trace_log_lvl()
x86/cpufeatures: Enable new AVX512 cpu features
x86/cpuid: Provide get_scattered_cpuid_leaf()
x86/cpuid: Cleanup cpuid_regs definitions
x86/copy_user: Unify the code by removing the 64-bit asm _copy_*_user() variants
x86/unwind: Ensure stack grows down
x86/vdso: Set vDSO pointer only after success
x86/prctl/uapi: Remove #ifdef for CHECKPOINT_RESTORE
x86/unwind: Detect bad stack return address
x86/dumpstack: Warn on stack recursion
x86/unwind: Warn on bad frame pointer
x86/decoder: Use stderr if insn sanity test fails
x86/decoder: Use stdout if insn decoder test is successful
mm/page_alloc: Remove kernel address exposure in free_reserved_area()
x86/dumpstack: Remove raw stack dump
...
Currently, when tracepoint_printk is set (enabled by the "tp_printk" kernel
command line), it causes trace events to print via printk(). This is a very
dangerous operation, but is useful for debugging.
The issue is, it's seldom used, but it is always checked even if it's not
enabled by the kernel command line. Instead of having this feature called by
a branch against a variable, turn that variable into a static key, and this
will remove the test and jump.
To simplify things, the functions output_printk() and
trace_event_buffer_commit() were moved from trace_events.c to trace.c.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
For mostly historical reasons, the x86 oops dump shows the raw stack
values:
...
[registers]
Stack:
ffff880079af7350 ffff880079905400 0000000000000000 ffffc900008f3ae0
ffffffffa0196610 0000000000000001 00010000ffffffff 0000000087654321
0000000000000002 0000000000000000 0000000000000000 0000000000000000
Call Trace:
...
This seems to be an artifact from long ago, and probably isn't needed
anymore. It generally just adds noise to the dump, and it can be
actively harmful because it leaks kernel addresses.
Linus says:
"The stack dump actually goes back to forever, and it used to be
useful back in 1992 or so. But it used to be useful mainly because
stacks were simpler and we didn't have very good call traces anyway. I
definitely remember having used them - I just do not remember having
used them in the last ten+ years.
Of course, it's still true that if you can trigger an oops, you've
likely already lost the security game, but since the stack dump is so
useless, let's aim to just remove it and make games like the above
harder."
This also removes the related 'kstack=' cmdline option and the
'kstack_depth_to_print' sysctl.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/e83bd50df52d8fe88e94d2566426ae40d813bf8f.1477405374.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The last user of this tunable was removed in 2012 in commit:
82958366cf ("sched: Replace update_shares weight distribution with per-entity computation")
Delete it since its very existence confuses people.
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20161019141059.26408-1-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull misc vfs updates from Al Viro:
"Assorted misc bits and pieces.
There are several single-topic branches left after this (rename2
series from Miklos, current_time series from Deepa Dinamani, xattr
series from Andreas, uaccess stuff from from me) and I'd prefer to
send those separately"
* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (39 commits)
proc: switch auxv to use of __mem_open()
hpfs: support FIEMAP
cifs: get rid of unused arguments of CIFSSMBWrite()
posix_acl: uapi header split
posix_acl: xattr representation cleanups
fs/aio.c: eliminate redundant loads in put_aio_ring_file
fs/internal.h: add const to ns_dentry_operations declaration
compat: remove compat_printk()
fs/buffer.c: make __getblk_slow() static
proc: unsigned file descriptors
fs/file: more unsigned file descriptors
fs: compat: remove redundant check of nr_segs
cachefiles: Fix attempt to read i_blocks after deleting file [ver #2]
cifs: don't use memcpy() to copy struct iov_iter
get rid of separate multipage fault-in primitives
fs: Avoid premature clearing of capabilities
fs: Give dentry to inode_change_ok() instead of inode
fuse: Propagate dentry down to inode_change_ok()
ceph: Propagate dentry down to inode_change_ok()
xfs: Propagate dentry down to inode_change_ok()
...
Pull namespace updates from Eric Biederman:
"This set of changes is a number of smaller things that have been
overlooked in other development cycles focused on more fundamental
change. The devpts changes are small things that were a distraction
until we managed to kill off DEVPTS_MULTPLE_INSTANCES. There is an
trivial regression fix to autofs for the unprivileged mount changes
that went in last cycle. A pair of ioctls has been added by Andrey
Vagin making it is possible to discover the relationships between
namespaces when referring to them through file descriptors.
The big user visible change is starting to add simple resource limits
to catch programs that misbehave. With namespaces in general and user
namespaces in particular allowing users to use more kinds of
resources, it has become important to have something to limit errant
programs. Because the purpose of these limits is to catch errant
programs the code needs to be inexpensive to use as it always on, and
the default limits need to be high enough that well behaved programs
on well behaved systems don't encounter them.
To this end, after some review I have implemented per user per user
namespace limits, and use them to limit the number of namespaces. The
limits being per user mean that one user can not exhause the limits of
another user. The limits being per user namespace allow contexts where
the limit is 0 and security conscious folks can remove from their
threat anlysis the code used to manage namespaces (as they have
historically done as it root only). At the same time the limits being
per user namespace allow other parts of the system to use namespaces.
Namespaces are increasingly being used in application sand boxing
scenarios so an all or nothing disable for the entire system for the
security conscious folks makes increasing use of these sandboxes
impossible.
There is also added a limit on the maximum number of mounts present in
a single mount namespace. It is nontrivial to guess what a reasonable
system wide limit on the number of mount structure in the kernel would
be, especially as it various based on how a system is using
containers. A limit on the number of mounts in a mount namespace
however is much easier to understand and set. In most cases in
practice only about 1000 mounts are used. Given that some autofs
scenarious have the potential to be 30,000 to 50,000 mounts I have set
the default limit for the number of mounts at 100,000 which is well
above every known set of users but low enough that the mount hash
tables don't degrade unreaonsably.
These limits are a start. I expect this estabilishes a pattern that
other limits for resources that namespaces use will follow. There has
been interest in making inotify event limits per user per user
namespace as well as interest expressed in making details about what
is going on in the kernel more visible"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (28 commits)
autofs: Fix automounts by using current_real_cred()->uid
mnt: Add a per mount namespace limit on the number of mounts
netns: move {inc,dec}_net_namespaces into #ifdef
nsfs: Simplify __ns_get_path
tools/testing: add a test to check nsfs ioctl-s
nsfs: add ioctl to get a parent namespace
nsfs: add ioctl to get an owning user namespace for ns file descriptor
kernel: add a helper to get an owning user namespace for a namespace
devpts: Change the owner of /dev/pts/ptmx to the mounter of /dev/pts
devpts: Remove sync_filesystems
devpts: Make devpts_kill_sb safe if fsi is NULL
devpts: Simplify devpts_mount by using mount_nodev
devpts: Move the creation of /dev/pts/ptmx into fill_super
devpts: Move parse_mount_options into fill_super
userns: When the per user per user namespace limit is reached return ENOSPC
userns; Document per user per user namespace limits.
mntns: Add a limit on the number of mount namespaces.
netns: Add a limit on the number of net namespaces
cgroupns: Add a limit on the number of cgroup namespaces
ipcns: Add a limit on the number of ipc namespaces
...
CAI Qian <caiqian@redhat.com> pointed out that the semantics
of shared subtrees make it possible to create an exponentially
increasing number of mounts in a mount namespace.
mkdir /tmp/1 /tmp/2
mount --make-rshared /
for i in $(seq 1 20) ; do mount --bind /tmp/1 /tmp/2 ; done
Will create create 2^20 or 1048576 mounts, which is a practical problem
as some people have managed to hit this by accident.
As such CVE-2016-6213 was assigned.
Ian Kent <raven@themaw.net> described the situation for autofs users
as follows:
> The number of mounts for direct mount maps is usually not very large because of
> the way they are implemented, large direct mount maps can have performance
> problems. There can be anywhere from a few (likely case a few hundred) to less
> than 10000, plus mounts that have been triggered and not yet expired.
>
> Indirect mounts have one autofs mount at the root plus the number of mounts that
> have been triggered and not yet expired.
>
> The number of autofs indirect map entries can range from a few to the common
> case of several thousand and in rare cases up to between 30000 and 50000. I've
> not heard of people with maps larger than 50000 entries.
>
> The larger the number of map entries the greater the possibility for a large
> number of active mounts so it's not hard to expect cases of a 1000 or somewhat
> more active mounts.
So I am setting the default number of mounts allowed per mount
namespace at 100,000. This is more than enough for any use case I
know of, but small enough to quickly stop an exponential increase
in mounts. Which should be perfect to catch misconfigurations and
malfunctioning programs.
For anyone who needs a higher limit this can be changed by writing
to the new /proc/sys/fs/mount-max sysctl.
Tested-by: CAI Qian <caiqian@redhat.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
After 7e8e385aaf ("x86/compat: Remove sys32_vm86_warning"), this
function has become unused, so we can remove it as well.
Link: http://lkml.kernel.org/r/20160617142903.3070388-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
We have scripts which write to certain fields on 3.18 kernels but this
seems to be failing on 4.4 kernels. An entry which we write to here is
xfrm_aevent_rseqth which is u32.
echo 4294967295 > /proc/sys/net/core/xfrm_aevent_rseqth
Commit 230633d109 ("kernel/sysctl.c: detect overflows when converting
to int") prevented writing to sysctl entries when integer overflow
occurs. However, this does not apply to unsigned integers.
Heinrich suggested that we introduce a new option to handle 64 bit
limits and set min as 0 and max as UINT_MAX. This might not work as it
leads to issues similar to __do_proc_doulongvec_minmax. Alternatively,
we would need to change the datatype of the entry to 64 bit.
static int __do_proc_doulongvec_minmax(void *data, struct ctl_table
{
i = (unsigned long *) data; //This cast is causing to read beyond the size of data (u32)
vleft = table->maxlen / sizeof(unsigned long); //vleft is 0 because maxlen is sizeof(u32) which is lesser than sizeof(unsigned long) on x86_64.
Introduce a new proc handler proc_douintvec. Individual proc entries
will need to be updated to use the new handler.
[akpm@linux-foundation.org: coding-style fixes]
Fixes: 230633d109 ("kernel/sysctl.c:detect overflows when converting to int")
Link: http://lkml.kernel.org/r/1471479806-5252-1-git-send-email-subashab@codeaurora.org
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a "printk.devkmsg" kernel command line parameter which controls how
userspace writes into /dev/kmsg. It has three options:
* ratelimit - ratelimit logging from userspace.
* on - unlimited logging from userspace
* off - logging from userspace gets ignored
The default setting is to ratelimit the messages written to it.
This changes the kernel default setting of "on" to "ratelimit" and we do
that because we want to keep userspace spamming /dev/kmsg to sane
levels. This is especially moot when a small kernel log buffer wraps
around and messages get lost. So the ratelimiting setting should be a
sane setting where kernel messages should have a bit higher chance of
survival from all the spamming.
It additionally does not limit logging to /dev/kmsg while the system is
booting if we haven't disabled it on the command line.
Furthermore, we can control the logging from a lower priority sysctl
interface - kernel.printk_devkmsg.
That interface will succeed only if printk.devkmsg *hasn't* been
supplied on the command line. If it has, then printk.devkmsg is a
one-time setting which remains for the duration of the system lifetime.
This "locking" of the setting is to prevent userspace from changing the
logging on us through sysctl(2).
This patch is based on previous patches from Linus and Steven.
[bp@suse.de: fixes]
Link: http://lkml.kernel.org/r/20160719072344.GC25563@nazgul.tnic
Link: http://lkml.kernel.org/r/20160716061745.15795-3-bp@alien8.de
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Dave Young <dyoung@redhat.com>
Cc: Franck Bui <fbui@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As reclaim is now per-node based, convert zone_reclaim to be
node_reclaim. It is possible that a node will be reclaimed multiple
times if it has multiple zones but this is unavoidable without caching
all nodes traversed so far. The documentation and interface to
userspace is the same from a configuration perspective and will will be
similar in behaviour unless the node-local allocation requests were also
limited to lower zones.
Link: http://lkml.kernel.org/r/1467970510-21195-24-git-send-email-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It is not always easy to determine the cause of an RCU stall just by
analysing the RCU stall messages, mainly when the problem is caused
by the indirect starvation of rcu threads. For example, when preempt_rcu
is not awakened due to the starvation of a timer softirq.
We have been hard coding panic() in the RCU stall functions for
some time while testing the kernel-rt. But this is not possible in
some scenarios, like when supporting customers.
This patch implements the sysctl kernel.panic_on_rcu_stall. If
set to 1, the system will panic() when an RCU stall takes place,
enabling the capture of a vmcore. The vmcore provides a way to analyze
all kernel/tasks states, helping out to point to the culprit and the
solution for the stall.
The kernel.panic_on_rcu_stall sysctl is disabled by default.
Changes from v1:
- Fixed a typo in the git log
- The if(sysctl_panic_on_rcu_stall) panic() is in a static function
- Fixed the CONFIG_TINY_RCU compilation issue
- The var sysctl_panic_on_rcu_stall is now __read_mostly
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Reviewed-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Tested-by: "Luis Claudio R. Goncalves" <lgoncalv@redhat.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Pull perf updates from Ingo Molnar:
"Mostly tooling and PMU driver fixes, but also a number of late updates
such as the reworking of the call-chain size limiting logic to make
call-graph recording more robust, plus tooling side changes for the
new 'backwards ring-buffer' extension to the perf ring-buffer"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (34 commits)
perf record: Read from backward ring buffer
perf record: Rename variable to make code clear
perf record: Prevent reading invalid data in record__mmap_read
perf evlist: Add API to pause/resume
perf trace: Use the ptr->name beautifier as default for "filename" args
perf trace: Use the fd->name beautifier as default for "fd" args
perf report: Add srcline_from/to branch sort keys
perf evsel: Record fd into perf_mmap
perf evsel: Add overwrite attribute and check write_backward
perf tools: Set buildid dir under symfs when --symfs is provided
perf trace: Only auto set call-graph to "dwarf" when syscalls are being traced
perf annotate: Sort list of recognised instructions
perf annotate: Fix identification of ARM blt and bls instructions
perf tools: Fix usage of max_stack sysctl
perf callchain: Stop validating callchains by the max_stack sysctl
perf trace: Fix exit_group() formatting
perf top: Use machine->kptr_restrict_warned
perf trace: Warn when trying to resolve kernel addresses with kptr_restrict=1
perf machine: Do not bail out if not managing to read ref reloc symbol
perf/x86/intel/p4: Trival indentation fix, remove space
...
Provide /proc/sys/vm/stat_refresh to force an immediate update of
per-cpu into global vmstats: useful to avoid a sleep(2) or whatever
before checking counts when testing. Originally added to work around a
bug which left counts stranded indefinitely on a cpu going idle (an
inaccuracy magnified when small below-batch numbers represent "huge"
amounts of memory), but I believe that bug is now fixed: nonetheless,
this is still a useful knob.
Its schedule_on_each_cpu() is probably too expensive just to fold into
reading /proc/meminfo itself: give this mode 0600 to prevent abuse.
Allow a write or a read to do the same: nothing to read, but "grep -h
Shmem /proc/sys/vm/stat_refresh /proc/meminfo" is convenient. Oh, and
since global_page_state() itself is careful to disguise any underflow as
0, hack in an "Invalid argument" and pr_warn() if a counter is negative
after the refresh - this helped to fix a misaccounting of
NR_ISOLATED_FILE in my migration code.
But on recent kernels, I find that NR_ALLOC_BATCH and NR_PAGES_SCANNED
often go negative some of the time. I have not yet worked out why, but
have no evidence that it's actually harmful. Punt for the moment by
just ignoring the anomaly on those.
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Yang Shi <yang.shi@linaro.org>
Cc: Ning Qu <quning@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The perf_sample->ip_callchain->nr value includes all the entries in the
ip_callchain->ip[] array, real addresses and PERF_CONTEXT_{KERNEL,USER,etc},
while what the user expects is that what is in the kernel.perf_event_max_stack
sysctl or in the upcoming per event perf_event_attr.sample_max_stack knob be
honoured in terms of IP addresses in the stack trace.
So allocate a bunch of extra entries for contexts, and do the accounting
via perf_callchain_entry_ctx struct members.
A new sysctl, kernel.perf_event_max_contexts_per_stack is also
introduced for investigating possible bugs in the callchain
implementation by some arch.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Zefan Li <lizefan@huawei.com>
Link: http://lkml.kernel.org/n/tip-3b4wnqk340c4sg4gwkfdi9yk@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
