syz-executor6: vmalloc: allocation failure: 0 bytes, mode:0x24000c2(GFP_KERNEL|__GFP_HIGHMEM)
INFO: task loop0:12863 blocked for more than 120 seconds.
      Not tainted 4.9.109-ge1815b3 #52
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
loop0           D27080 12863      2 0x00000000
 ffff8801d7283000 ffff8801d850aa00 ffff880192ddb480 ffff8801d9483000
 ffff8801db221c18 ffff8801cc3eedf0 ffffffff839e8a8d 0000000041b58ab3
 ffffffff843c2288 ffffffff81236160 0000000000000000 ffff8801db2224e8
Call Trace:
 [<ffffffff839ea08f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3557
 [<ffffffff839f64a1>] schedule_timeout+0x861/0xf70 kernel/time/timer.c:1768
 [<ffffffff839e826a>] io_schedule_timeout+0x1ba/0x390 kernel/sched/core.c:5180
 [<ffffffff81e51f0c>] io_schedule include/linux/sched.h:460 [inline]
 [<ffffffff81e51f0c>] bt_get.isra.8+0x27c/0x780 block/blk-mq-tag.c:141
 [<ffffffff81e52e1c>] __blk_mq_get_tag block/blk-mq-tag.c:163 [inline]
 [<ffffffff81e52e1c>] blk_mq_get_tag+0xac/0x220 block/blk-mq-tag.c:192
 [<ffffffff81e4254a>] __blk_mq_alloc_request+0x2a/0xaa0 block/blk-mq.c:196
 [<ffffffff81e4494b>] blk_mq_map_request.isra.38+0x3ab/0x900 block/blk-mq.c:1207
 [<ffffffff81e4cd96>] blk_sq_make_request+0x1d6/0x1220 block/blk-mq.c:1374
 [<ffffffff81e1fcce>] generic_make_request+0x20e/0x9b0 block/blk-core.c:2055
 [<ffffffff81e20520>] submit_bio+0xb0/0x460 block/blk-core.c:2126
 [<ffffffff8164390a>] dio_bio_submit fs/direct-io.c:420 [inline]
 [<ffffffff8164390a>] do_blockdev_direct_IO+0x35da/0x5a80 fs/direct-io.c:1301
 [<ffffffff81645e55>] __blockdev_direct_IO+0xa5/0xd0 fs/direct-io.c:1360
 [<ffffffff8162fa00>] blkdev_direct_IO+0xa0/0xd0 fs/block_dev.c:183
 [<ffffffff8143e740>] generic_file_read_iter+0x660/0x1a90 mm/filemap.c:1951
 [<ffffffff81632605>] blkdev_read_iter+0x105/0x170 fs/block_dev.c:1738
 [<ffffffff825cdf13>] lo_rw_aio+0x6b3/0x8a0 drivers/block/loop.c:506
 [<ffffffff825ce4d7>] do_req_filebacked drivers/block/loop.c:543 [inline]
 [<ffffffff825ce4d7>] loop_handle_cmd drivers/block/loop.c:1698 [inline]
 [<ffffffff825ce4d7>] loop_queue_work+0x3d7/0x2320 drivers/block/loop.c:1710
 [<ffffffff8119d429>] kthread_worker_fn+0x249/0x6b0 kernel/kthread.c:627
 [<ffffffff8119d04d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff839f9b5c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373

Showing all locks held in the system:
2 locks held by khungtaskd/519:
 #0:  (rcu_read_lock){......}, at: [<ffffffff8136662c>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff8136662c>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81425cb7>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
1 lock held by rsyslogd/3570:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff815d803c>] __fdget_pos+0xac/0xd0 fs/file.c:781
2 locks held by getty/3666:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff839f7b32>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8211fce2>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2133
1 lock held by syz-executor2/3726:
 #0:  (&xt[i].mutex){+.+.+.}, at: [<ffffffff832798ac>] xt_find_table_lock+0x3c/0x3d0 net/netfilter/x_tables.c:1027
4 locks held by kworker/u4:4/3921:
 #0:  ("%s""netns"){.+.+.+}, at: [<ffffffff8118d02e>] work_static include/linux/workqueue.h:186 [inline]
 #0:  ("%s""netns"){.+.+.+}, at: [<ffffffff8118d02e>] set_work_data kernel/workqueue.c:617 [inline]
 #0:  ("%s""netns"){.+.+.+}, at: [<ffffffff8118d02e>] set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
 #0:  ("%s""netns"){.+.+.+}, at: [<ffffffff8118d02e>] process_one_work+0x6ee/0x1500 kernel/workqueue.c:2085
 #1:  (net_cleanup_work){+.+.+.}, at: [<ffffffff8118d068>] process_one_work+0x728/0x1500 kernel/workqueue.c:2089
 #2:  (net_mutex){+.+.+.}, at: [<ffffffff8305ca3f>] cleanup_net+0x13f/0x630 net/core/net_namespace.c:439
 #3:  (rcu_preempt_state.barrier_mutex){+.+...}, at: [<ffffffff81282f7d>] _rcu_barrier+0x5d/0x340 kernel/rcu/tree.c:3637

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 519 Comm: khungtaskd Not tainted 4.9.109-ge1815b3 #52
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d96efd08 ffffffff81eb3e29 0000000000000000 0000000000000000
 0000000000000000 0000000000000001 ffffffff810b9580 ffff8801d96efd40
 ffffffff81ebf127 0000000000000000 0000000000000000 0000000000000003
Call Trace:
 [<ffffffff81eb3e29>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb3e29>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81ebf127>] nmi_cpu_backtrace.cold.2+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81ebf0ba>] nmi_trigger_cpumask_backtrace+0x12a/0x14f lib/nmi_backtrace.c:60
 [<ffffffff810b9684>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff81366bc4>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81366bc4>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81366bc4>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81366bc4>] watchdog+0x6b4/0xa20 kernel/hung_task.c:239
 [<ffffffff8119d04d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff839f9b5c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 7 Comm: rcu_preempt Not tainted 4.9.109-ge1815b3 #52
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801d9a39800 task.stack: ffff8801d9a48000
RIP: 0010:[<ffffffff812888b3>] 
c [<ffffffff812888b3>] __read_once_size include/linux/compiler.h:243 [inline]
RIP: 0010:[<ffffffff812888b3>] 
c [<ffffffff812888b3>] rcu_gp_kthread+0x1b3/0x2110 kernel/rcu/tree.c:2194
RSP: 0018:ffff8801d9a4fc30  EFLAGS: 00000246
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: 0000000000000006 RSI: 0000000000000001 RDI: ffffffff85b2d6c0
RBP: ffff8801d9a4fe00 R08: ffff8801db3228d8 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801db322880
R13: ffffffff846e0300 R14: ffff8801999eda18 R15: ffffffff846e0680
FS:  0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000007272ec CR3: 00000001c735b000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 0000000000021c00
c ffffffff846e072a
c ffffffff846e0728
c ffffffff846e0a40
c
 ffffffff846e0a38
c ffffffff846e0a30
c ffffffff846e0a28
c ffffffff846e09f0
c
 ffffffff846e0a18
c ffffffff846e0698
c ffffffff846e06c8
c fffffbfff08dc0e5
c
Call Trace:
 [<ffffffff8119d04d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff839f9b5c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
Code: 
ce0 
c07 
c83 
cc0 
c01 
c88 
c85 
cd7 
cfe 
cff 
cff 
c48 
c89 
cf8 
c48 
cc1 
ce8 
c03 
c48 
c01 
cd8 
c48 
c89 
c85 
c88 
cfe 
cff 
cff 
c48 
c89 
cf8 
c83 
ce0 
c07 
c83 
cc0 
c01 
c88 
c85 
cd6 
cfe 
cff 
cff 
c<48> 
c8b 
c85 
cd8 
cfe 
cff 
cff 
c0f 
cb6 
c00 
c38 
c85 
cd7 
cfe 
cff 
cff 
c7c 
c08 
c84 
cc0 
c0f 
c