INFO: task syz-executor.2:12841 blocked for more than 143 seconds.
      Not tainted 6.1.0-rc1-next-20221021-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.2  state:D stack:25456 pid:12841 ppid:28147  flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5191 [inline]
 __schedule+0xae9/0x53f0 kernel/sched/core.c:6503
 schedule+0xda/0x1b0 kernel/sched/core.c:6579
 wb_wait_for_completion+0x17e/0x240 fs/fs-writeback.c:191
 __writeback_inodes_sb_nr+0x1d7/0x280 fs/fs-writeback.c:2620
 try_to_writeback_inodes_sb+0x94/0xc0 fs/fs-writeback.c:2668
 ext4_nonda_switch+0x1aa/0x1f0 fs/ext4/inode.c:2950
 ext4_da_write_begin+0x16b/0xab0 fs/ext4/inode.c:2977
 generic_perform_write+0x252/0x570 mm/filemap.c:3771
 ext4_buffered_write_iter+0x15b/0x460 fs/ext4/file.c:285
 ext4_file_write_iter+0x8b8/0x16e0 fs/ext4/file.c:700
 __kernel_write_iter+0x25e/0x730 fs/read_write.c:517
 dump_emit_page fs/coredump.c:862 [inline]
 dump_user_range+0x244/0x680 fs/coredump.c:913
 elf_core_dump+0x26de/0x3510 fs/binfmt_elf.c:2311
 do_coredump+0x26ea/0x3c10 fs/coredump.c:760
 get_signal+0x1be1/0x2430 kernel/signal.c:2844
 arch_do_signal_or_restart+0x75/0x5b0 arch/x86/kernel/signal.c:306
 exit_to_user_mode_loop kernel/entry/common.c:168 [inline]
 exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:203
 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:309
 exc_page_fault+0xbc/0x170 arch/x86/mm/fault.c:1578
 asm_exc_machine_check-0xe/0x40
RIP: 0033:0x0
RSP: 002b:0000000020000118 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007fac387abf80 RCX: 00007fac3868b5f9
RDX: 0000000020000140 RSI: 0000000020000110 RDI: 0000000022100280
RBP: 00007fac386e67b0 R08: 00000000200001c0 R09: 00000000200001c0
R10: 0000000020000180 R11: 0000000000000202 R12: 0000000000000000
R13: 00007ffde503abaf R14: 00007fac397ff300 R15: 0000000000022000
 </TASK>
INFO: lockdep is turned off.
NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.1.0-rc1-next-20221021-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 nmi_cpu_backtrace.cold+0x24/0x18a lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x32f/0x3c0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
 watchdog+0xc71/0xfc0 kernel/hung_task.c:377
 kthread+0x2e4/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 25638 Comm: kworker/u4:9 Not tainted 6.1.0-rc1-next-20221021-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022
Workqueue: bat_events batadv_nc_worker
RIP: 0010:__rcu_read_unlock+0xef/0x5b0 kernel/rcu/tree_plugin.h:427
Code: 48 8b 1c 25 40 97 03 00 48 8d bb 3c 04 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 <83> c0 03 38 d0 7c 08 84 d2 0f 85 5e 01 00 00 8b 83 3c 04 00 00 3d
RSP: 0018:ffffc900057afc58 EFLAGS: 00000202
RAX: 0000000000000004 RBX: ffff88801f410000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff89216e9e RDI: ffff88801f41043c
RBP: ffff88801f410000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 000000000008c001 R12: ffff88801f410000
R13: 0000000000000000 R14: dffffc0000000000 R15: 00000000000003b1
FS:  0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb25e30ca60 CR3: 00000000265d0000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 rcu_read_unlock include/linux/rcupdate.h:791 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline]
 batadv_nc_worker+0x853/0xfa0 net/batman-adv/network-coding.c:719
 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289
 worker_thread+0x665/0x1080 kernel/workqueue.c:2436
 kthread+0x2e4/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>