linux-stable.git/kernel, branch v3.18.121

kprobes: Make list and blacklist root user read only

2018-09-05T07:16:23+00:00

commit f2a3ab36077222437b4826fc76111caa14562b7c upstream.

Since the blacklist and list files on debugfs indicates
a sensitive address information to reader, it should be
restricted to the root user.

Suggested-by: Thomas Richter 
Suggested-by: Ingo Molnar 
Signed-off-by: Masami Hiramatsu 
Cc: Ananth N Mavinakayanahalli 
Cc: Anil S Keshavamurthy 
Cc: Arnd Bergmann 
Cc: David Howells 
Cc: David S . Miller 
Cc: Heiko Carstens 
Cc: Jon Medhurst 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Tobin C . Harding 
Cc: Will Deacon 
Cc: acme@kernel.org
Cc: akpm@linux-foundation.org
Cc: brueckner@linux.vnet.ibm.com
Cc: linux-arch@vger.kernel.org
Cc: rostedt@goodmis.org
Cc: schwidefsky@de.ibm.com
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/lkml/152491890171.9916.5183693615601334087.stgit@devbox
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

sched/sysctl: Check user input value of sysctl_sched_time_avg

2018-09-05T07:16:19+00:00

commit 5ccba44ba118a5000cccc50076b0344632459779 upstream.

System will hang if user set sysctl_sched_time_avg to 0:

  [root@XXX ~]# sysctl kernel.sched_time_avg_ms=0

  Stack traceback for pid 0
  0xffff883f6406c600 0 0 1 3 R 0xffff883f6406cf50 *swapper/3
  ffff883f7ccc3ae8 0000000000000018 ffffffff810c4dd0 0000000000000000
  0000000000017800 ffff883f7ccc3d78 0000000000000003 ffff883f7ccc3bf8
  ffffffff810c4fc9 ffff883f7ccc3c08 00000000810c5043 ffff883f7ccc3c08
  Call Trace:
   [] ? update_group_capacity+0x110/0x200
  [] ? update_sd_lb_stats+0x109/0x600
  [] ? find_busiest_group+0x47/0x530
  [] ? load_balance+0x194/0x900
  [] ? update_rq_clock.part.83+0x1a/0xe0
  [] ? rebalance_domains+0x152/0x290
  [] ? run_rebalance_domains+0xdc/0x1d0
  [] ? __do_softirq+0xfb/0x320
  [] ? irq_exit+0x125/0x130
  [] ? scheduler_ipi+0x97/0x160
  [] ? smp_reschedule_interrupt+0x29/0x30
  [] ? reschedule_interrupt+0x6e/0x80
    [] ? cpuidle_enter_state+0xcc/0x230
  [] ? cpuidle_enter_state+0x9c/0x230
  [] ? cpuidle_enter+0x17/0x20
  [] ? cpu_startup_entry+0x38c/0x420
  [] ? start_secondary+0x173/0x1e0

Because divide-by-zero error happens in function:

update_group_capacity()
  update_cpu_capacity()
    scale_rt_capacity()
     {
          ...
          total = sched_avg_period() + delta;
          used = div_u64(avg, total);
          ...
     }

To fix this issue, check user input value of sysctl_sched_time_avg, keep
it unchanged when hitting invalid input, and set the minimum limit of
sysctl_sched_time_avg to 1 ms.

Reported-by: James Puthukattukaran 
Signed-off-by: Ethan Zhao 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: efault@gmx.de
Cc: ethan.kernel@gmail.com
Cc: keescook@chromium.org
Cc: mcgrof@kernel.org
Cc: 
Link: http://lkml.kernel.org/r/1504504774-18253-1-git-send-email-ethan.zhao@oracle.com
Signed-off-by: Ingo Molnar 
Cc: Steve Muckle 
Signed-off-by: Greg Kroah-Hartman

tracing: Use __printf markup to silence compiler

2018-08-28T05:21:35+00:00

[ Upstream commit 26b68dd2f48fe7699a89f0cfbb9f4a650dc1c837 ]

Silence warnings (triggered at W=1) by adding relevant __printf attributes.

  CC      kernel/trace/trace.o
kernel/trace/trace.c: In function ‘__trace_array_vprintk’:
kernel/trace/trace.c:2979:2: warning: function might be possible candidate for ‘gnu_printf’ format attribute [-Wsuggest-attribute=format]
  len = vscnprintf(tbuffer, TRACE_BUF_SIZE, fmt, args);
  ^~~
  AR      kernel/trace/built-in.o

Link: http://lkml.kernel.org/r/20180308205843.27447-1-malat@debian.org

Signed-off-by: Mathieu Malaterre 
Signed-off-by: Steven Rostedt (VMware) 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

locking/lockdep: Do not record IRQ state within lockdep code

2018-08-28T05:21:33+00:00

[ Upstream commit fcc784be837714a9173b372ff9fb9b514590dad9 ]

While debugging where things were going wrong with mapping
enabling/disabling interrupts with the lockdep state and actual real
enabling and disabling interrupts, I had to silent the IRQ
disabling/enabling in debug_check_no_locks_freed() because it was
always showing up as it was called before the splat was.

Use raw_local_irq_save/restore() for not only debug_check_no_locks_freed()
but for all internal lockdep functions, as they hide useful information
about where interrupts were used incorrectly last.

Signed-off-by: Steven Rostedt (VMware) 
Cc: Andrew Morton 
Cc: Linus Torvalds 
Cc: Paul E. McKenney 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Will Deacon 
Link: https://lkml.kernel.org/lkml/20180404140630.3f4f4c7a@gandalf.local.home
Signed-off-by: Ingo Molnar 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

ring_buffer: tracing: Inherit the tracing setting to next ring buffer

2018-08-09T10:20:36+00:00

commit 73c8d8945505acdcbae137c2e00a1232e0be709f upstream.

Maintain the tracing on/off setting of the ring_buffer when switching
to the trace buffer snapshot.

Taking a snapshot is done by swapping the backup ring buffer
(max_tr_buffer). But since the tracing on/off setting is defined
by the ring buffer, when swapping it, the tracing on/off setting
can also be changed. This causes a strange result like below:

  /sys/kernel/debug/tracing # cat tracing_on
  1
  /sys/kernel/debug/tracing # echo 0 > tracing_on
  /sys/kernel/debug/tracing # cat tracing_on
  0
  /sys/kernel/debug/tracing # echo 1 > snapshot
  /sys/kernel/debug/tracing # cat tracing_on
  1
  /sys/kernel/debug/tracing # echo 1 > snapshot
  /sys/kernel/debug/tracing # cat tracing_on
  0

We don't touch tracing_on, but snapshot changes tracing_on
setting each time. This is an anomaly, because user doesn't know
that each "ring_buffer" stores its own tracing-enable state and
the snapshot is done by swapping ring buffers.

Link: http://lkml.kernel.org/r/153149929558.11274.11730609978254724394.stgit@devbox

Cc: Ingo Molnar 
Cc: Shuah Khan 
Cc: Tom Zanussi 
Cc: Hiraku Toyooka 
Cc: stable@vger.kernel.org
Fixes: debdd57f5145 ("tracing: Make a snapshot feature available from userspace")
Signed-off-by: Masami Hiramatsu 
[ Updated commit log and comment in the code ]
Signed-off-by: Steven Rostedt (VMware) 
Signed-off-by: Sudip Mukherjee 
Signed-off-by: Greg Kroah-Hartman

bpf: fix references to free_bpf_prog_info() in comments

2018-08-09T10:20:30+00:00

[ Upstream commit ab7f5bf0928be2f148d000a6eaa6c0a36e74750e ]

Comments in the verifier refer to free_bpf_prog_info() which
seems to have never existed in tree.  Replace it with
free_used_maps().

Signed-off-by: Jakub Kicinski 
Reviewed-by: Quentin Monnet 
Signed-off-by: Daniel Borkmann 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

tracing: Quiet gcc warning about maybe unused link variable

2018-08-09T10:20:25+00:00

commit 2519c1bbe38d7acacc9aacba303ca6f97482ed53 upstream.

Commit 57ea2a34adf4 ("tracing/kprobes: Fix trace_probe flags on
enable_trace_kprobe() failure") added an if statement that depends on another
if statement that gcc doesn't see will initialize the "link" variable and
gives the warning:

 "warning: 'link' may be used uninitialized in this function"

It is really a false positive, but to quiet the warning, and also to make
sure that it never actually is used uninitialized, initialize the "link"
variable to NULL and add an if (!WARN_ON_ONCE(!link)) where the compiler
thinks it could be used uninitialized.

Cc: stable@vger.kernel.org
Fixes: 57ea2a34adf4 ("tracing/kprobes: Fix trace_probe flags on enable_trace_kprobe() failure")
Reported-by: kbuild test robot 
Signed-off-by: Steven Rostedt (VMware) 
Signed-off-by: Greg Kroah-Hartman

tracing/kprobes: Fix trace_probe flags on enable_trace_kprobe() failure

2018-08-09T10:20:25+00:00

commit 57ea2a34adf40f3a6e88409aafcf803b8945619a upstream.

If enable_trace_kprobe fails to enable the probe in enable_k(ret)probe
it returns an error, but does not unset the tp flags it set previously.
This results in a probe being considered enabled and failures like being
unable to remove the probe through kprobe_events file since probes_open()
expects every probe to be disabled.

Link: http://lkml.kernel.org/r/20180725102826.8300-1-asavkov@redhat.com
Link: http://lkml.kernel.org/r/20180725142038.4765-1-asavkov@redhat.com

Cc: Ingo Molnar 
Cc: stable@vger.kernel.org
Fixes: 41a7dd420c57 ("tracing/kprobes: Support ftrace_event_file base multibuffer")
Acked-by: Masami Hiramatsu 
Reviewed-by: Josh Poimboeuf 
Signed-off-by: Artem Savkov 
Signed-off-by: Steven Rostedt (VMware) 
Signed-off-by: Greg Kroah-Hartman

tracing: Fix possible double free in event_enable_trigger_func()

2018-08-09T10:20:25+00:00

commit 15cc78644d0075e76d59476a4467e7143860f660 upstream.

There was a case that triggered a double free in event_trigger_callback()
due to the called reg() function freeing the trigger_data and then it
getting freed again by the error return by the caller. The solution there
was to up the trigger_data ref count.

Code inspection found that event_enable_trigger_func() has the same issue,
but is not as easy to trigger (requires harder to trigger failures). It
needs to be solved slightly different as it needs more to clean up when the
reg() function fails.

Link: http://lkml.kernel.org/r/20180725124008.7008e586@gandalf.local.home

Cc: stable@vger.kernel.org
Fixes: 7862ad1846e99 ("tracing: Add 'enable_event' and 'disable_event' event trigger commands")
Reivewed-by: Masami Hiramatsu 
Signed-off-by: Steven Rostedt (VMware) 
Signed-off-by: Greg Kroah-Hartman

tracing: Fix double free of event_trigger_data

2018-08-09T10:20:24+00:00

commit 1863c387259b629e4ebfb255495f67cd06aa229b upstream.

Running the following:

 # cd /sys/kernel/debug/tracing
 # echo 500000 > buffer_size_kb
[ Or some other number that takes up most of memory ]
 # echo snapshot > events/sched/sched_switch/trigger

Triggers the following bug:

 ------------[ cut here ]------------
 kernel BUG at mm/slub.c:296!
 invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC PTI
 CPU: 6 PID: 6878 Comm: bash Not tainted 4.18.0-rc6-test+ #1066
 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016
 RIP: 0010:kfree+0x16c/0x180
 Code: 05 41 0f b6 72 51 5b 5d 41 5c 4c 89 d7 e9 ac b3 f8 ff 48 89 d9 48 89 da 41 b8 01 00 00 00 5b 5d 41 5c 4c 89 d6 e9 f4 f3 ff ff <0f> 0b 0f 0b 48 8b 3d d9 d8 f9 00 e9 c1 fe ff ff 0f 1f 40 00 0f 1f
 RSP: 0018:ffffb654436d3d88 EFLAGS: 00010246
 RAX: ffff91a9d50f3d80 RBX: ffff91a9d50f3d80 RCX: ffff91a9d50f3d80
 RDX: 00000000000006a4 RSI: ffff91a9de5a60e0 RDI: ffff91a9d9803500
 RBP: ffffffff8d267c80 R08: 00000000000260e0 R09: ffffffff8c1a56be
 R10: fffff0d404543cc0 R11: 0000000000000389 R12: ffffffff8c1a56be
 R13: ffff91a9d9930e18 R14: ffff91a98c0c2890 R15: ffffffff8d267d00
 FS:  00007f363ea64700(0000) GS:ffff91a9de580000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 000055c1cacc8e10 CR3: 00000000d9b46003 CR4: 00000000001606e0
 Call Trace:
  event_trigger_callback+0xee/0x1d0
  event_trigger_write+0xfc/0x1a0
  __vfs_write+0x33/0x190
  ? handle_mm_fault+0x115/0x230
  ? _cond_resched+0x16/0x40
  vfs_write+0xb0/0x190
  ksys_write+0x52/0xc0
  do_syscall_64+0x5a/0x160
  entry_SYSCALL_64_after_hwframe+0x49/0xbe
 RIP: 0033:0x7f363e16ab50
 Code: 73 01 c3 48 8b 0d 38 83 2c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 79 db 2c 00 00 75 10 b8 01 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 1e e3 01 00 48 89 04 24
 RSP: 002b:00007fff9a4c6378 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
 RAX: ffffffffffffffda RBX: 0000000000000009 RCX: 00007f363e16ab50
 RDX: 0000000000000009 RSI: 000055c1cacc8e10 RDI: 0000000000000001
 RBP: 000055c1cacc8e10 R08: 00007f363e435740 R09: 00007f363ea64700
 R10: 0000000000000073 R11: 0000000000000246 R12: 0000000000000009
 R13: 0000000000000001 R14: 00007f363e4345e0 R15: 00007f363e4303c0
 Modules linked in: ip6table_filter ip6_tables snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core snd_seq snd_seq_device i915 snd_pcm snd_timer i2c_i801 snd soundcore i2c_algo_bit drm_kms_helper
86_pkg_temp_thermal video kvm_intel kvm irqbypass wmi e1000e
 ---[ end trace d301afa879ddfa25 ]---

The cause is because the register_snapshot_trigger() call failed to
allocate the snapshot buffer, and then called unregister_trigger()
which freed the data that was passed to it. Then on return to the
function that called register_snapshot_trigger(), as it sees it
failed to register, it frees the trigger_data again and causes
a double free.

By calling event_trigger_init() on the trigger_data (which only ups
the reference counter for it), and then event_trigger_free() afterward,
the trigger_data would not get freed by the registering trigger function
as it would only up and lower the ref count for it. If the register
trigger function fails, then the event_trigger_free() called after it
will free the trigger data normally.

Link: http://lkml.kernel.org/r/20180724191331.738eb819@gandalf.local.home

Cc: stable@vger.kerne.org
Fixes: 93e31ffbf417 ("tracing: Add 'snapshot' event trigger command")
Reported-by: Masami Hiramatsu 
Reviewed-by: Masami Hiramatsu 
Signed-off-by: Steven Rostedt (VMware) 
Signed-off-by: Greg Kroah-Hartman