syz-executor2 (28823) used greatest stack depth: 12800 bytes left
==================================================================
BUG: KASAN: slab-out-of-bounds in __read_once_size include/linux/compiler.h:188 [inline]
BUG: KASAN: slab-out-of-bounds in list_empty include/linux/list.h:203 [inline]
BUG: KASAN: slab-out-of-bounds in shrink_slab_memcg mm/vmscan.c:595 [inline]
BUG: KASAN: slab-out-of-bounds in shrink_slab+0xa04/0xa60 mm/vmscan.c:671
Read of size 8 at addr ffff880182bf2fd8 by task syz-executor5/28843

CPU: 1 PID: 28843 Comm: syz-executor5 Not tainted 4.18.0-rc4-next-20180713+ #7
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113
 print_address_description+0x6c/0x20b mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.7+0x242/0x30d mm/kasan/report.c:412
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
 __read_once_size include/linux/compiler.h:188 [inline]
 list_empty include/linux/list.h:203 [inline]
 shrink_slab_memcg mm/vmscan.c:595 [inline]
 shrink_slab+0xa04/0xa60 mm/vmscan.c:671
 shrink_node+0x429/0x16a0 mm/vmscan.c:2735
 shrink_zones mm/vmscan.c:2964 [inline]
 do_try_to_free_pages+0x3e7/0x1290 mm/vmscan.c:3026
 try_to_free_mem_cgroup_pages+0x49d/0xc90 mm/vmscan.c:3324
 memory_high_write+0x283/0x310 mm/memcontrol.c:5611
 cgroup_file_write+0x31f/0x840 kernel/cgroup/cgroup.c:3502
 kernfs_fop_write+0x2ba/0x480 fs/kernfs/file.c:316
 __vfs_write+0x117/0x9d0 fs/read_write.c:485
 vfs_write+0x1fc/0x560 fs/read_write.c:549
 ksys_write+0x101/0x260 fs/read_write.c:598
 __do_sys_write fs/read_write.c:610 [inline]
 __se_sys_write fs/read_write.c:607 [inline]
 __x64_sys_write+0x73/0xb0 fs/read_write.c:607
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x455ab9
Code: 1d ba fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb b9 fb ff c3 66 2e 0f 1f 84 00 00 00 00 
RSP: 002b:00007fb42c32fc68 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fb42c3306d4 RCX: 0000000000455ab9
RDX: 0000000000000001 RSI: 0000000020000000 RDI: 0000000000000015
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004c2cae R14: 00000000004d4cc8 R15: 0000000000000000

Allocated by task 27929:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553
 __do_kmalloc mm/slab.c:3718 [inline]
 __kmalloc_track_caller+0x14a/0x760 mm/slab.c:3733
 kstrdup+0x39/0x70 mm/util.c:56
 kstrdup_const+0x66/0x80 mm/util.c:77
 alloc_vfsmnt+0x189/0x9a0 fs/namespace.c:192
 clone_mnt+0x124/0x1500 fs/namespace.c:947
 copy_tree+0x485/0xb00 fs/namespace.c:1676
 propagate_one+0x4e3/0x930 fs/pnode.c:266
 propagate_mnt+0x18a/0x3e0 fs/pnode.c:316
 attach_recursive_mnt+0x60c/0xb70 fs/namespace.c:1915
 graft_tree+0x1aa/0x240 fs/namespace.c:2015
 do_loopback fs/namespace.c:2143 [inline]
 do_mount+0x1a90/0x1fb0 fs/namespace.c:2883
 ksys_mount+0x12d/0x140 fs/namespace.c:3105
 __do_sys_mount fs/namespace.c:3119 [inline]
 __se_sys_mount fs/namespace.c:3116 [inline]
 __x64_sys_mount+0xbe/0x150 fs/namespace.c:3116
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 18211:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3498 [inline]
 kfree+0xd9/0x260 mm/slab.c:3813
 kfree_const+0x59/0x70 mm/util.c:38
 free_vfsmnt+0x37/0x80 fs/namespace.c:559
 delayed_free_vfsmnt+0x16/0x20 fs/namespace.c:568
 __rcu_reclaim kernel/rcu/rcu.h:236 [inline]
 rcu_do_batch kernel/rcu/tree.c:2576 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:2880 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:2847 [inline]
 rcu_process_callbacks+0xf98/0x2860 kernel/rcu/tree.c:2864
 __do_softirq+0x2e8/0xb17 kernel/softirq.c:288

The buggy address belongs to the object at ffff880182bf2f80
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 56 bytes to the right of
 32-byte region [ffff880182bf2f80, ffff880182bf2fa0)
The buggy address belongs to the page:
page:ffffea00060afc80 count:1 mapcount:0 mapping:ffff8801da8001c0 index:0xffff880182bf2fc1
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffffea0006df3008 ffffea000669ff48 ffff8801da8001c0
raw: ffff880182bf2fc1 ffff880182bf2000 000000010000003f 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff880182bf2e80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff880182bf2f00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
>ffff880182bf2f80: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc
                                                    ^
 ffff880182bf3000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff880182bf3080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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