kernel BUG at mm/huge_memory.c:LINE!

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 4cd1b60def51 Add linux-next specific files for 20190102
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=147760d3400000
kernel config: https://syzkaller.appspot.com/x/.config?x=e8ea56601353001c
dashboard link: https://syzkaller.appspot.com/bug?extid=8e075128f7db8555391a
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+8e0751...@syzkaller.appspotmail.com

raw: 01fffc000009000d dead000000000100 dead000000000200 ffff88809a33f5b1
raw: 0000000000020000 0000000000000000 0000020000000000 ffff888095368000
page dumped because: VM_BUG_ON_PAGE(compound_mapcount(head))
page->mem_cgroup:ffff888095368000
------------[ cut here ]------------
kernel BUG at mm/huge_memory.c:2683!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 1551 Comm: kswapd0 Not tainted 4.20.0-next-20190102 #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:split_huge_page_to_list+0x2161/0x2ac0 mm/huge_memory.c:2683
Code: ff e8 33 35 b8 ff 48 8b 85 10 fc ff ff 4c 8d 70 ff e9 1e ea ff ff e8
1e 35 b8 ff 48 c7 c6 a0 a3 54 88 4c 89 ef e8 0f 15 ea ff <0f> 0b 48 89 85
10 fc ff ff e8 01 35 b8 ff 48 8b 85 10 fc ff ff 4c
RSP: 0018:ffff8880a5f36de8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8880a5f371d8 RCX: 0000000000000000
RDX: ffffed1014be6d6e RSI: ffffffff81b3831e RDI: ffffed1014be6dae
RBP: ffff8880a5f37200 R08: 0000000000000021 R09: ffffed1015cc5021
R10: ffffed1015cc5020 R11: ffff8880ae628107 R12: ffffea0000e80080
R13: ffffea0000e80000 R14: 00000000fffffffe R15: 01fffc000009000d
FS: 0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020003030 CR3: 0000000219267000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
split_huge_page include/linux/huge_mm.h:148 [inline]
deferred_split_scan+0xa47/0x11d0 mm/huge_memory.c:2820
do_shrink_slab+0x4e5/0xd30 mm/vmscan.c:561
shrink_slab mm/vmscan.c:710 [inline]
shrink_slab+0x6bb/0x8c0 mm/vmscan.c:690
shrink_node+0x61a/0x17e0 mm/vmscan.c:2776
kswapd_shrink_node mm/vmscan.c:3535 [inline]
balance_pgdat+0xb00/0x18b0 mm/vmscan.c:3693
kswapd+0x839/0x1330 mm/vmscan.c:3948
kthread+0x357/0x430 kernel/kthread.c:246
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
Modules linked in:
kobject: 'loop1' (000000002d2ad2ad): kobject_uevent_env
kobject: 'loop1' (000000002d2ad2ad): fill_kobj_path: path
= '/devices/virtual/block/loop1'
kobject: 'loop3' (000000003c94a079): kobject_uevent_env
kobject: 'loop3' (000000003c94a079): fill_kobj_path: path
= '/devices/virtual/block/loop3'
kobject: 'loop5' (0000000000e89d9d): kobject_uevent_env
kobject: 'loop5' (0000000000e89d9d): fill_kobj_path: path
= '/devices/virtual/block/loop5'
kobject: 'loop2' (000000001a685ee7): kobject_uevent_env
kobject: 'loop2' (000000001a685ee7): fill_kobj_path: path
= '/devices/virtual/block/loop2'
kobject: 'loop3' (000000003c94a079): kobject_uevent_env
kobject: 'loop3' (000000003c94a079): fill_kobj_path: path
= '/devices/virtual/block/loop3'
---[ end trace a543f5c1741fca97 ]---
kobject: 'loop0' (00000000aa59ea1f): kobject_uevent_env
RIP: 0010:split_huge_page_to_list+0x2161/0x2ac0 mm/huge_memory.c:2683
Code: ff e8 33 35 b8 ff 48 8b 85 10 fc ff ff 4c 8d 70 ff e9 1e ea ff ff e8
1e 35 b8 ff 48 c7 c6 a0 a3 54 88 4c 89 ef e8 0f 15 ea ff <0f> 0b 48 89 85
10 fc ff ff e8 01 35 b8 ff 48 8b 85 10 fc ff ff 4c
kobject: 'loop0' (00000000aa59ea1f): fill_kobj_path: path
= '/devices/virtual/block/loop0'
RSP: 0018:ffff8880a5f36de8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8880a5f371d8 RCX: 0000000000000000
RDX: ffffed1014be6d6e RSI: ffffffff81b3831e RDI: ffffed1014be6dae
RBP: ffff8880a5f37200 R08: 0000000000000021 R09: ffffed1015cc5021
netlink: 'syz-executor0': attribute type 22 has an invalid length.
R10: ffffed1015cc5020 R11: ffff8880ae628107 R12: ffffea0000e80080
R13: ffffea0000e80000 R14: 00000000fffffffe R15: 01fffc000009000d
FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
kobject: 'loop1' (000000002d2ad2ad): kobject_uevent_env
kobject: 'loop1' (000000002d2ad2ad): fill_kobj_path: path
= '/devices/virtual/block/loop1'
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004efb18 CR3: 00000000702a7000 CR4: 00000000001426e0
kobject: 'loop5' (0000000000e89d9d): kobject_uevent_env
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
kobject: 'loop5' (0000000000e89d9d): fill_kobj_path: path
= '/devices/virtual/block/loop5'
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
kobject: 'loop3' (000000003c94a079): kobject_uevent_env


---
This bug is generated by a bot. It may contain errors.
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syzbot.

[Konstantin Khlebnikov]

On 03.01.2019 13:43, syzbot wrote:
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit:    4cd1b60def51 Add linux-next specific files for 20190102
> git tree:       linux-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=147760d3400000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=e8ea56601353001c
> dashboard link: https://syzkaller.appspot.com/bug?extid=8e075128f7db8555391a
> compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
>
> Unfortunately, I don't have any reproducer for this crash yet.
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+8e0751...@syzkaller.appspotmail.com

Few more lines from "console output"

[ 549.659441] page:ffffea0000e80000 count:512 mapcount:0 mapping:ffff88809a33f5b1 index:0x20000 compound_mapcount: -1
[ 549.746649] anon
[ 549.746665] flags: 0x1fffc000009000d(locked|uptodate|dirty|head|swapbacked)

I've got couple of these for 4.14.
Maybe related but this happened with THP tmpfs.


<1>[220723.475439] huge_memory: total_mapcount: 63, page_count(): 576
<0>[220723.475474] page:ffffea0024ee8000 count:576 mapcount:0 mapping:ffff881813235550 index:0x0 compound_mapcount: 0
<0>[220723.475512] flags: 0x10000000004807d(locked|referenced|uptodate|dirty|lru|active|head|swapbacked)
<1>[220723.475545] raw: 010000000004807d ffff881813235550 0000000000000000 00000240ffffffff
<1>[220723.475573] raw: ffffea004c099a20 ffffea002bd9e020 0000000000000000 ffff883018044800
<1>[220723.475601] page dumped because: total_mapcount(head) > 0
<1>[220723.475621] page->mem_cgroup:ffff883018044800
<4>[220723.475644] ------------[ cut here ]------------
<2>[220723.475645] kernel BUG at mm/huge_memory.c:2652!
<4>[220723.475667] invalid opcode: 0000 [#1] SMP PTI
<4>[220723.475684] Modules linked in: xt_nat xt_limit overlay ip6table_nat nf_nat_ipv6 nf_nat veth tcp_diag inet_diag unix_diag xt_NFLOG
nfnetlink_log nfnetlink ip6t_REJECT nf_reject_ipv6 nf_log_ipv6 nf_log_common xt_LOG nf_conntrack_ipv6 nf_defrag_ipv6 xt_u32 ip6table_raw
xt_conntrack ip6table_filter xt_tcpudp xt_CT nf_conntrack iptable_raw xt_multiport iptable_filter bridge ip6_tables ip_tables x_tables
sch_fq_codel sch_hfsc netconsole configfs 8021q mrp garp stp llc intel_rapl sb_edac x86_pkg_temp_thermal intel_powerclamp mgag200 coretemp
ttm kvm_intel drm_kms_helper drm kvm fb_sys_fops sysimgblt input_leds sysfillrect syscopyarea irqbypass lpc_ich mfd_core ghash_clmulni_intel
shpchp ioatdma wmi tcp_bbr ip6_tunnel tunnel6 mlx4_en mlx4_core devlink tcp_nv tcp_htcp raid456 async_raid6_recov async_pq async_xor
<4>[220723.475954] xor async_memcpy async_tx raid10 igb isci dca libsas i2c_algo_bit ptp scsi_transport_sas pps_core raid6_pq libcrc32c
raid1 raid0 multipath linear [last unloaded: ipmi_msghandler]
<4>[220723.476021] CPU: 5 PID: 529913 Comm: qpipe-updater Not tainted 4.14.80-33 #1
<4>[220723.476047] Hardware name: Aquarius Aquarius Server/X9DRW, BIOS 3.0c 10/30/2014
<4>[220723.476074] task: ffff8817b98f3900 task.stack: ffffc900311d4000
<4>[220723.476099] RIP: 0010:split_huge_page_to_list+0x7b5/0x8d0
<4>[220723.476120] RSP: 0018:ffffc900311d76a0 EFLAGS: 00010086
<4>[220723.476140] RAX: 0000000000000021 RBX: ffff881813235550 RCX: 0000000000000006
<4>[220723.476165] RDX: 0000000000000007 RSI: 0000000000000082 RDI: ffff88181fb55730
<4>[220723.476190] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000c20
<4>[220723.476216] R10: ffffc900311d7690 R11: 0000000000000001 R12: 0000000000000000
<4>[220723.476241] R13: ffffea0024ee8000 R14: ffff88187fffb000 R15: ffffea0024ee8000
<4>[220723.476267] FS: 00007fe7a69097c0(0000) GS:ffff88181fb40000(0000) knlGS:0000000000000000
<4>[220723.476296] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
<4>[220723.476317] CR2: 00007fe78c1e1000 CR3: 0000001815530005 CR4: 00000000000606e0
<4>[220723.476342] Call Trace:
<4>[220723.476358] ? find_get_entry+0x20/0x140
<4>[220723.476377] shmem_unused_huge_shrink+0x184/0x3f0
<4>[220723.476398] super_cache_scan+0x184/0x190
<4>[220723.476416] shrink_slab.part.54+0x1ec/0x430
<4>[220723.476434] shrink_node+0x300/0x310
<4>[220723.476451] do_try_to_free_pages+0xe3/0x350
<4>[220723.476469] try_to_free_pages+0xe4/0x1d0
<4>[220723.476487] __alloc_pages_slowpath+0x3a5/0xe70
<4>[220723.476507] __alloc_pages_nodemask+0x25c/0x2a0
<4>[220723.476526] shmem_alloc_hugepage+0xc7/0x110
<4>[220723.476545] ? __radix_tree_create+0x168/0x1f0
<4>[220723.476563] ? release_pages+0x2c8/0x3a0
<4>[220723.476579] ? release_pages+0x2c8/0x3a0
<4>[220723.477420] ? __activate_page+0x200/0x2d0
<4>[220723.478254] ? percpu_counter_add_batch+0x52/0x70
<4>[220723.479095] shmem_alloc_and_acct_page+0x108/0x1d0
<4>[220723.479926] shmem_getpage_gfp+0x4ef/0xdf0
<4>[220723.480736] shmem_write_begin+0x35/0x60
<4>[220723.481514] generic_perform_write+0xaf/0x1b0
<4>[220723.482293] __generic_file_write_iter+0x196/0x1e0
<4>[220723.483061] generic_file_write_iter+0xe6/0x1f0
<4>[220723.483820] __vfs_write+0xdc/0x150
<4>[220723.484573] vfs_write+0xc5/0x1c0
<4>[220723.485324] SyS_write+0x42/0x90
<4>[220723.486067] do_syscall_64+0x67/0x120
<4>[220723.486790] entry_SYSCALL_64_after_hwframe+0x3d/0xa2
<4>[220723.487496] RIP: 0033:0x7fe7a60d8330
<4>[220723.488175] RSP: 002b:00007ffc05104af8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
<4>[220723.488851] RAX: ffffffffffffffda RBX: 00007fe785e00000 RCX: 00007fe7a60d8330
<4>[220723.489511] RDX: 0000000011be3b28 RSI: 00007fe785e00000 RDI: 0000000000000003
<4>[220723.490156] RBP: 0000000011be3b28 R08: 00007fe7a69097c0 R09: 00007ffc05104bb7
<4>[220723.490770] R10: 00007ffc051048c0 R11: 0000000000000246 R12: 0000000107b88c00
<4>[220723.491364] R13: 00007ffc051057b8 R14: 0000000011be3b28 R15: 00000001072886b8
<4>[220723.491933] Code: 8b 54 24 08 48 c7 c7 28 54 06 82 e8 51 59 eb ff 49 8b 45 20 a8 01 0f 85 1b 01 00 00 48 c7 c6 8c 50 06 82 4c 89 ef
e8 cb 64 fb ff <0f> 0b 48 c7 c6 60 53 06 82 4c 89 ff e8 ba 64 fb ff 0f 0b e8 23
<1>[220723.493137] RIP: split_huge_page_to_list+0x7b5/0x8d0 RSP: ffffc900311d76a0
<4>[220723.493731] ---[ end trace 74a2900540d3546c ]---
<5>[220723.494322] ---[ now 2018-12-24 07:08:37+03 ]---

[Kirill A. Shutemov]

On Mon, Jan 07, 2019 at 07:57:38PM +0300, Konstantin Khlebnikov wrote:
> On 03.01.2019 13:43, syzbot wrote:
> > Hello,
> >
> > syzbot found the following crash on:
> >
> > HEAD commit:    4cd1b60def51 Add linux-next specific files for 20190102
> > git tree:       linux-next
> > console output: https://syzkaller.appspot.com/x/log.txt?x=147760d3400000
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=e8ea56601353001c
> > dashboard link: https://syzkaller.appspot.com/bug?extid=8e075128f7db8555391a
> > compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
> >
> > Unfortunately, I don't have any reproducer for this crash yet.
> >
> > IMPORTANT: if you fix the bug, please add the following tag to the commit:
> > Reported-by: syzbot+8e0751...@syzkaller.appspotmail.com
>
>
> Few more lines from "console output"
>
> [ 549.659441] page:ffffea0000e80000 count:512 mapcount:0 mapping:ffff88809a33f5b1 index:0x20000 compound_mapcount: -1
> [ 549.746649] anon
> [ 549.746665] flags: 0x1fffc000009000d(locked|uptodate|dirty|head|swapbacked)

That's obviously underflow of compound_mapcount, but I don't see a
possible cause for it.

Ying, you've looked recently into THP rmap code. Maybe you have any
insight on the problem?

--
Kirill A. Shutemov

[Konstantin Khlebnikov]

with this debug patch on top of 4.14.94

--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2651,12 +2651,14 @@ int split_huge_page_to_list(struct page *page, struct list_head *list)
ret = 0;
} else {
if (IS_ENABLED(CONFIG_DEBUG_VM) && mapcount) {
+ int i;
+
pr_alert("total_mapcount: %u, page_count(): %u\n",
mapcount, count);
- if (PageTail(page))
- dump_page(head, NULL);
- dump_page(page, "total_mapcount(head) > 0");
- BUG();
+ for (i = 0; i < HPAGE_PMD_NR; i++)
+ if (!i || (atomic_read(&head[i]._mapcount) + 1))
+ dump_page(head + i, "mapcount > 0");
+ WARN_ON(1);
}
spin_unlock(&pgdata->split_queue_lock);
fail: if (mapping)



I've that some tail pages are still mapped:

huge_memory: total_mapcount: 63, page_count(): 576

page:ffffea007b588000 count:576 mapcount:0 mapping:ffff8897a557c4a0 index:0x0 compound_mapcount: 0
flags: 0x50000000004807d(locked|referenced|uptodate|dirty|lru|active|head|swapbacked)
raw: 050000000004807d ffff8897a557c4a0 0000000000000000 00000240ffffffff
raw: ffffea0063818020 ffffea008a67a020 0000000000000000 ffff88af2e528800
page dumped because: mapcount > 0
page->mem_cgroup:ffff88af2e528800
page:ffffea007b588f80 count:0 mapcount:1 mapping:dead000000000400 index:0x3e compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b588fc0 count:0 mapcount:1 mapping:dead000000000400 index:0x3f compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589000 count:0 mapcount:1 mapping:dead000000000400 index:0x40 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589040 count:0 mapcount:1 mapping:dead000000000400 index:0x41 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589080 count:0 mapcount:1 mapping:dead000000000400 index:0x42 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b5890c0 count:0 mapcount:1 mapping:dead000000000400 index:0x43 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589100 count:0 mapcount:1 mapping:dead000000000400 index:0x44 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589140 count:0 mapcount:1 mapping:dead000000000400 index:0x45 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589180 count:0 mapcount:1 mapping:dead000000000400 index:0x46 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b5891c0 count:0 mapcount:1 mapping:dead000000000400 index:0x47 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589200 count:0 mapcount:1 mapping:dead000000000400 index:0x48 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589240 count:0 mapcount:1 mapping:dead000000000400 index:0x49 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589280 count:0 mapcount:1 mapping:dead000000000400 index:0x4a compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b5892c0 count:0 mapcount:1 mapping:dead000000000400 index:0x4b compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589300 count:0 mapcount:1 mapping:dead000000000400 index:0x4c compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589340 count:0 mapcount:1 mapping:dead000000000400 index:0x4d compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589380 count:0 mapcount:1 mapping:dead000000000400 index:0x4e compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b5893c0 count:0 mapcount:1 mapping:dead000000000400 index:0x4f compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589400 count:0 mapcount:1 mapping:dead000000000400 index:0x50 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589440 count:0 mapcount:1 mapping:dead000000000400 index:0x51 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589480 count:0 mapcount:1 mapping:dead000000000400 index:0x52 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b5894c0 count:0 mapcount:1 mapping:dead000000000400 index:0x53 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589500 count:0 mapcount:1 mapping:dead000000000400 index:0x54 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589540 count:0 mapcount:1 mapping:dead000000000400 index:0x55 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589580 count:0 mapcount:1 mapping:dead000000000400 index:0x56 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b5895c0 count:0 mapcount:1 mapping:dead000000000400 index:0x57 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589600 count:0 mapcount:1 mapping:dead000000000400 index:0x58 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589640 count:0 mapcount:1 mapping:dead000000000400 index:0x59 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589680 count:0 mapcount:1 mapping:dead000000000400 index:0x5a compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b5896c0 count:0 mapcount:1 mapping:dead000000000400 index:0x5b compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589700 count:0 mapcount:1 mapping:dead000000000400 index:0x5c compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589740 count:0 mapcount:1 mapping:dead000000000400 index:0x5d compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589780 count:0 mapcount:1 mapping:dead000000000400 index:0x5e compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b5897c0 count:0 mapcount:1 mapping:dead000000000400 index:0x5f compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589800 count:0 mapcount:1 mapping:dead000000000400 index:0x60 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589840 count:0 mapcount:1 mapping:dead000000000400 index:0x61 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589880 count:0 mapcount:1 mapping:dead000000000400 index:0x62 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b5898c0 count:0 mapcount:1 mapping:dead000000000400 index:0x63 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589900 count:0 mapcount:1 mapping:dead000000000400 index:0x64 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589940 count:0 mapcount:1 mapping:dead000000000400 index:0x65 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589980 count:0 mapcount:1 mapping:dead000000000400 index:0x66 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b5899c0 count:0 mapcount:1 mapping:dead000000000400 index:0x67 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589a00 count:0 mapcount:1 mapping:dead000000000400 index:0x68 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589a40 count:0 mapcount:1 mapping:dead000000000400 index:0x69 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589a80 count:0 mapcount:1 mapping:dead000000000400 index:0x6a compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589ac0 count:0 mapcount:1 mapping:dead000000000400 index:0x6b compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589b00 count:0 mapcount:1 mapping:dead000000000400 index:0x6c compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589b40 count:0 mapcount:1 mapping:dead000000000400 index:0x6d compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589b80 count:0 mapcount:1 mapping:dead000000000400 index:0x6e compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589bc0 count:0 mapcount:1 mapping:dead000000000400 index:0x6f compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589c00 count:0 mapcount:1 mapping:dead000000000400 index:0x70 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589c40 count:0 mapcount:1 mapping:dead000000000400 index:0x71 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589c80 count:0 mapcount:1 mapping:dead000000000400 index:0x72 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589cc0 count:0 mapcount:1 mapping:dead000000000400 index:0x73 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589d00 count:0 mapcount:1 mapping:dead000000000400 index:0x74 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589d40 count:0 mapcount:1 mapping:dead000000000400 index:0x75 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589d80 count:0 mapcount:1 mapping:dead000000000400 index:0x76 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589dc0 count:0 mapcount:1 mapping:dead000000000400 index:0x77 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589e00 count:0 mapcount:1 mapping:dead000000000400 index:0x78 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589e40 count:0 mapcount:1 mapping:dead000000000400 index:0x79 compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589e80 count:0 mapcount:1 mapping:dead000000000400 index:0x7a compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589ec0 count:0 mapcount:1 mapping:dead000000000400 index:0x7b compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
page:ffffea007b589f00 count:0 mapcount:1 mapping:dead000000000400 index:0x7c compound_mapcount: 0
flags: 0x500000000000000()
raw: 0500000000000000 dead000000000400 0000000000000001 0000000000000000
raw: ffffea007b588001 dead000000000200 0000000000000000 0000000000000000
page dumped because: mapcount > 0
------------[ cut here ]------------
WARNING: CPU: 5 PID: 237 at mm/huge_memory.c:2661 split_huge_page_to_list+0x790/0x8e0
Modules linked in: overlay tcp_nv i2c_i801 binfmt_misc veth ipt_REJECT nf_reject_ipv4 ip6t_REJECT nf_reject_ipv6 nf_log_ipv6 nf_log_common
xt_LOG nf_conntrack_ipv6 nf_defrag_ipv6 xt_u32 ip6table_raw xt_conntrack xt_tcpudp xt_CT nf_conntrack iptable_raw xt_multiport
ip6table_filter iptable_filter ip6_tables ip_tables x_tables tcp_htcp ip6_tunnel tunnel6 tcp_bbr sch_fq_codel sch_hfsc netconsole tcp_diag
inet_diag unix_diag configfs 8021q garp mrp stp llc intel_rapl sb_edac x86_pkg_temp_thermal intel_powerclamp ipmi_ssif coretemp kvm_intel
kvm irqbypass input_leds ghash_clmulni_intel ipmi_si ipmi_devintf ioatdma ipmi_msghandler lpc_ich mfd_core shpchp mlx4_en mlx4_core devlink
autofs4 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath
linear raid10 mgag200 drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm isci igb drm dca libsas ptp scsi_transport_sas
pps_core i2c_algo_bit wmi [last unloaded: netconsole]
CPU: 5 PID: 237 Comm: kswapd0 Not tainted 4.14.94-38 #1
Hardware name: Supermicro X9DRW/X9DRW, BIOS 3.0c 10/30/2014
task: ffff8898149ae3c0 task.stack: ffffc9000d734000
RIP: 0010:split_huge_page_to_list+0x790/0x8e0
RSP: 0018:ffffc9000d737b68 EFLAGS: 00010046
RAX: 00000000ffffffff RBX: ffff8897a557c4a0 RCX: 0000000000000006
RDX: ffffea007b590000 RSI: 0000000000000000 RDI: ffff88981fb55730
RBP: 0000000000000000 R08: 0000000000000000 R09: 000000000000100e
R10: ffffc9000d737b58 R11: 0000000000000001 R12: 0000000000000200
R13: ffff88b07fff8000 R14: 0000000000000286 R15: ffffea007b588000
FS: 0000000000000000(0000) GS:ffff88981fb40000(0000) knlGS:0000000000000000

CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 00007f7b0f746018 CR3: 000000000220a006 CR4: 00000000001606e0
Call Trace:
? find_get_entry+0x20/0x140
shmem_unused_huge_shrink+0x184/0x3f0
super_cache_scan+0x184/0x190
shrink_slab.part.54+0x1c2/0x3f0
shrink_node+0x468/0x480
balance_pgdat+0x176/0x340
kswapd+0x1ba/0x440
? wait_woken+0xb0/0xb0
kthread+0x10a/0x140
? balance_pgdat+0x340/0x340
? kthread_create_on_node+0x40/0x40
ret_from_fork+0x35/0x40
Code: ff 74 17 48 89 d7 48 c7 c6 c4 5a 06 82 48 89 14 24 e8 b5 63 fb ff 48 8b 14 24 41 83 c4 01 48 83 c2 40 41 81 fc 00 02 00 00 75 cb <0f>
0b 41 c6 85 c4 45 00 00 00 65 ff 0d cf 74 dd 7e 48 85 db 0f
---[ end trace 4c5fba0af251fbf4 ]---

[Eric Biggers]

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Let's assume this was fixed by:

commit a53190a4aaa36494f4d7209fd1fcc6f2ee08e0e0
Author: Yang Shi <yang...@linux.alibaba.com>
Date: Tue Aug 13 15:37:18 2019 -0700

mm: mempolicy: handle vma with unmovable pages mapped correctly in mbind

When running syzkaller internally, we ran into the below bug on 4.9.x
kernel:

kernel BUG at mm/huge_memory.c:2124!

...

#syz fix: mm: mempolicy: handle vma with unmovable pages mapped correctly in mbind

- Eric