Re: slub freelist issue / BUG: unable to handle page fault for address: 000000003ffe0018

Rafael J. Wysocki
2020-06-12T12:27:21Z

On 6/11/2020 3:40 AM, Kaneda, Erik wrote:
>
>> -----Original Message-----
>> From: Vegard Nossum <vegard.nossum@oracle.com>
>> Sent: Friday, June 5, 2020 7:45 AM
>> To: Vlastimil Babka <vbabka@suse.cz>; Rafael J. Wysocki
>> <rafael@kernel.org>; Moore, Robert <robert.moore@intel.com>; Kaneda,
>> Erik <erik.kaneda@intel.com>
>> Cc: Kees Cook <keescook@chromium.org>; Wysocki, Rafael J
>> <rafael.j.wysocki@intel.com>; Christoph Lameter <cl@linux.com>; Andrew
>> Morton <akpm@linux-foundation.org>; Marco Elver <elver@google.com>;
>> Waiman Long <longman@redhat.com>; LKML <linux-
>> kernel@vger.kernel.org>; Linux MM <linux-mm@kvack.org>; ACPI Devel
>> Maling List <linux-acpi@vger.kernel.org>; Len Brown <lenb@kernel.org>;
>> Steven Rostedt <rostedt@goodmis.org>
>> Subject: Re: slub freelist issue / BUG: unable to handle page fault for
>> address: 000000003ffe0018
>>
>> On 2020-06-05 16:08, Vlastimil Babka wrote:
>>> On 6/5/20 3:12 PM, Rafael J. Wysocki wrote:
>>>> On Fri, Jun 5, 2020 at 2:48 PM Vegard Nossum
>> <vegard.nossum@oracle.com> wrote:
>>>>> On 2020-06-05 11:36, Vegard Nossum wrote:
>>>>>> On 2020-06-05 11:11, Vlastimil Babka wrote:
>>>>>>> On 6/4/20 8:46 PM, Vlastimil Babka wrote:
>>>>>>>> On 6/4/20 7:57 PM, Kees Cook wrote:
>>>>>>>>> On Thu, Jun 04, 2020 at 07:20:18PM +0200, Vegard Nossum wrote:
>>>>>>>>>> On 2020-06-04 19:18, Vlastimil Babka wrote:
>>>>>>>>>>> On 6/4/20 7:14 PM, Vegard Nossum wrote:
>>>>>>>>>>>> Hi all,
>>>>>>>>>>>>
>>>>>>>>>>>> I ran into a boot problem with latest linus/master
>>>>>>>>>>>> (6929f71e46bdddbf1c4d67c2728648176c67c555) that manifests
>> like this:
>>>>>>>>>>> Hi, what's the .config you use?
>>>>>>>>>> Pretty much x86_64 defconfig minus a few options (PCI, USB,
>>>>>>>>>> ...)
>>>>>>>>> Oh yes indeed. I immediately crash in the same way with this config.
>>>>>>>>> I'll
>>>>>>>>> start digging...
>>>>>>>>>
>>>>>>>>> (defconfig finishes boot)
>>>>>>>> This is funny, booting with slub_debug=F results in:
>>>>>>>> I'm not sure if it's ACPI or ftrace wrong here, but looks like
>>>>>>>> the changed free pointer offset merely exposes a bug in something
>>>>>>>> else.
>>>>>>> So, with Kees' patch reverted, booting with slub_debug=F (or even
>>>>>>> more specific slub_debug=F,ftrace_event_field) also hits this bug
>>>>>>> below. I wanted to bisect it, but v5.7 was also bad, and also
>>>>>>> v5.6. Didn't try further in history. So it's not new at all, and
>>>>>>> likely very specific to your config+QEMU? (and related to the ACPI
>>>>>>> error messages that precede it?).
>>>>>> I see it too, but not on v5.0. I can bisect it.
>>>>> commit 67a72420a326b45514deb3f212085fb2cd1595b5
>>>>> Author: Bob Moore <robert.moore@intel.com>
>>>>> Date: Fri Aug 16 14:43:21 2019 -0700
>>>>>
>>>>> ACPICA: Increase total number of possible Owner IDs
>>>>>
>>>>> ACPICA commit 1f1652dad88b9d767767bc1f7eb4f7d99e6b5324
>>>>>
>>>>> From 255 to 4095 possible IDs.
>>>>>
>>>>> Link: https://github.com/acpica/acpica/commit/1f1652da
>>>>> Reported-by: Hedi Berriche <hedi.berriche @hpe.com>
>>>>> Signed-off-by: Bob Moore <robert.moore@intel.com>
>>>>> Signed-off-by: Erik Schmauss <erik.schmauss@intel.com>
>>>>> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>>>> Bob, Erik, did we miss something in that patch?
>>> Maybe the patch just changes layout in a way that exposes the bug.
>>>
>>> Anyway the "ftrace_event_field" cache is not really involved, this is
>>> just because of slab merging. After adding "slub_nomerge" to
>>> "slub_debug=F", it starts making more sense, as the cache becomes
>>> Acpi-Namespace
>>>
>>> [ 0.140408] ------------[ cut here ]------------
>>> [ 0.140837] cache_from_obj: Wrong slab cache. Acpi-Namespace but
>> object is from kmalloc-64
>>> [ 0.141406] WARNING: CPU: 0 PID: 1 at mm/slab.h:524
>> kmem_cache_free+0x1d3/0x250
>>> [ 0.142105] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.7.0+ #45
>>> [ 0.142393] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
>> BIOS rel-1.13.0-0-gf21b5a4-rebuilt.opensuse.org 04/01/2014
>>> [ 0.142393] RIP: 0010:kmem_cache_free+0x1d3/0x250
>>> [ 0.142393] Code: 18 4d 85 ed 0f 84 10 ff ff ff 4c 39 ed 74 2f 49 8b 4d 58 48
>> 8b 55 58 48 c7 c6 10 47 a1 ac 48 c7 c7 00 c2 b0 ac e8 b1 cc eb ff <0f> 0b 48 89 de
>> 4c 89 ef e8 10 d7 ff ff 48 8b 15 59 36 9b 00 4c 89
>>> [ 0.142393] RSP: 0018:ffffb39cc0013dc0 EFLAGS: 00010282
>>> [ 0.142393] RAX: 0000000000000000 RBX: ffff937287409e00 RCX:
>> 0000000000000000
>>> [ 0.142393] RDX: 0000000000000001 RSI: 0000000000000092 RDI:
>> ffffffffacfdd32c
>>> [ 0.142393] RBP: ffff93728742ef00 R08: ffffb39cc0013c7d R09:
>> 00000000000000fc
>>> [ 0.142393] R10: ffffb39cc0013c78 R11: ffffb39cc0013c7d R12:
>> ffff937307409e00
>>> [ 0.142393] R13: ffff937287401d00 R14: 0000000000000000 R15:
>> 0000000000000000
>>> [ 0.142393] FS: 0000000000000000(0000) GS:ffff937287a00000(0000)
>> knlGS:0000000000000000
>>> [ 0.142393] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>>> [ 0.142393] CR2: 0000000000000000 CR3: 0000000003a0a000 CR4:
>> 00000000003406f0
>>> [ 0.142393] Call Trace:
>>> [ 0.142393] acpi_os_release_object+0x5/0x10
>>> [ 0.142393] acpi_ns_delete_children+0x46/0x59
>>> [ 0.142393] acpi_ns_delete_namespace_subtree+0x5c/0x79
>>> [ 0.142393] ? acpi_sleep_proc_init+0x1f/0x1f
>>> [ 0.142393] acpi_ns_terminate+0xc/0x31
>>> [ 0.142393] acpi_ut_subsystem_shutdown+0x45/0xa3
>>> [ 0.142393] ? acpi_sleep_proc_init+0x1f/0x1f
>>> [ 0.142393] acpi_terminate+0x5/0xf
>>> [ 0.142393] acpi_init+0x27b/0x308
>>> [ 0.142393] ? video_setup+0x79/0x79
>>> [ 0.142393] do_one_initcall+0x7b/0x160
>>> [ 0.142393] kernel_init_freeable+0x190/0x1f2
>>> [ 0.142393] ? rest_init+0x9a/0x9a
>>> [ 0.142393] kernel_init+0x5/0xf6
>>> [ 0.142393] ret_from_fork+0x22/0x30
>>> [ 0.142393] ---[ end trace 3539f236ef812ba1 ]---
>>> [ 0.142396] ------------[ cut here ]------------
>>>
>>> I've also changed the warning so it's not printed just once, and also
>>> prints tracking info (see the hunk at the end of my mail, I'll turn this to a
>> proper patch later).
>>> With "slub_debug=FU slub_nomerge" there are now multiple warnings,
>> but they all look the same:
>>> [ 0.143815] ------------[ cut here ]------------
>>> [ 0.144131] cache_from_obj: Wrong slab cache. Acpi-Namespace but
>> object is from kmalloc-64
>>> [ 0.144929] WARNING: CPU: 0 PID: 1 at mm/slab.h:524
>> kmem_cache_free+0x1d3/0x250
>>> [ 0.145129] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.7.0+ #45
>>> [ 0.145129] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
>> BIOS rel-1.13.0-0-gf21b5a4-rebuilt.opensuse.org 04/01/2014
>>> [ 0.145129] RIP: 0010:kmem_cache_free+0x1d3/0x250
>>> [ 0.145129] Code: 18 4d 85 ed 0f 84 10 ff ff ff 4c 39 ed 74 2f 49 8b 4d 58 48
>> 8b 55 58 48 c7 c6 10 47 c1 8d 48 c7 c7 00 c2 d0 8d e8 b1 cc eb ff <0f> 0b 48 89 de
>> 4c 89 ef e8 10 d7 ff ff 48 8b 15 59 36 9b 00 4c 89
>>> [ 0.145129] RSP: 0018:ffff990b80013dc0 EFLAGS: 00010282
>>> [ 0.145129] RAX: 0000000000000000 RBX: ffff972d474ada80 RCX:
>> 0000000000000000
>>> [ 0.145129] RDX: 0000000000000001 RSI: 0000000000000092 RDI:
>> ffffffff8e1dd32c
>>> [ 0.145129] RBP: ffff972d47425680 R08: ffff990b80013c7d R09:
>> 00000000000000fc
>>> [ 0.145129] R10: ffff990b80013c78 R11: ffff990b80013c7d R12:
>> ffff972dc74ada80
>>> [ 0.145129] R13: ffff972d474038c0 R14: 0000000000000000 R15:
>> 0000000000000000
>>> [ 0.145129] FS: 0000000000000000(0000) GS:ffff972d47a00000(0000)
>> knlGS:0000000000000000
>>> [ 0.145129] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>>> [ 0.145129] CR2: 0000000000000000 CR3: 000000000660a000 CR4:
>> 00000000003406f0
>>> [ 0.145129] Call Trace:
>>> [ 0.145129] acpi_os_release_object+0x5/0x10
>>> [ 0.145129] acpi_ns_delete_children+0x46/0x59
>>> [ 0.145129] acpi_ns_delete_namespace_subtree+0x5c/0x79
>>> [ 0.145129] ? acpi_sleep_proc_init+0x1f/0x1f
>>> [ 0.145129] acpi_ns_terminate+0xc/0x31
>>> [ 0.145129] acpi_ut_subsystem_shutdown+0x45/0xa3
>>> [ 0.145129] ? acpi_sleep_proc_init+0x1f/0x1f
>>> [ 0.145129] acpi_terminate+0x5/0xf
>>> [ 0.145129] acpi_init+0x27b/0x308
>>> [ 0.145129] ? video_setup+0x79/0x79
>>> [ 0.145129] do_one_initcall+0x7b/0x160
>>> [ 0.145129] kernel_init_freeable+0x190/0x1f2
>>> [ 0.145129] ? rest_init+0x9a/0x9a
>>> [ 0.145129] kernel_init+0x5/0xf6
>>> [ 0.145129] ret_from_fork+0x22/0x30
>>> [ 0.145129] ---[ end trace 574554fca7bd06bb ]---
>>> [ 0.145133] INFO: Allocated in acpi_ns_root_initialize+0xb6/0x2d1 age=58
>> cpu=0 pid=0
>>> [ 0.145881] kmem_cache_alloc_trace+0x1a9/0x1c0
>>> [ 0.146132] acpi_ns_root_initialize+0xb6/0x2d1
>>> [ 0.146578] acpi_initialize_subsystem+0x65/0xa8
>>> [ 0.147024] acpi_early_init+0x5d/0xd1
>>> [ 0.147132] start_kernel+0x45b/0x518
>>> [ 0.147491] secondary_startup_64+0xb6/0xc0
>>> [ 0.147897] ------------[ cut here ]------------
>>>
>>> And it seems ACPI is allocating an object via kmalloc() and then
>>> freeing it via kmem_cache_free(<"Acpi-Namespace" kmem_cache>) which
>> is wrong.
>>>> ./scripts/faddr2line vmlinux 'acpi_ns_root_initialize+0xb6'
>>> acpi_ns_root_initialize+0xb6/0x2d1:
>>> kmalloc at include/linux/slab.h:555
>>> (inlined by) kzalloc at include/linux/slab.h:669 (inlined by)
>>> acpi_os_allocate_zeroed at include/acpi/platform/aclinuxex.h:57
>>> (inlined by) acpi_ns_root_initialize at
>>> drivers/acpi/acpica/nsaccess.c:102
>>>
> Hi Vegard,
>
>> That's it :-) This fixes it for me:
> We'll take this patch for ACPICA and it will be in the next release.
>
> Rafael, do you want to take this as a part of the next rc?

Yes, I do.

Cheers!