INFO: task kworker/u9:21:8850 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u9:21   state:D stack:14232 pid:8850  tgid:8850  ppid:2      task_flags:0x4248060 flags:0x00004000
Workqueue: writeback wb_workfn (flush-bcachefs-19)
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_timeout+0x12b/0x270
 __closure_sync_timeout+0x282/0x3a0
 __bch2_wait_on_allocator+0x112/0x240
 __bch2_write+0x31ef/0x3900
 __bch2_writepage+0x1536/0x2790
 write_cache_pages+0x64/0x100
 bch2_writepages+0xf9/0x2d0
 do_writepages+0x32e/0x550
 __writeback_single_inode+0x145/0xff0
 writeback_sb_inodes+0x6c7/0x1010
 __writeback_inodes_wb+0x111/0x240
 wb_writeback+0x44f/0xaf0
 wb_workfn+0xaef/0xef0
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
INFO: task syz.7.1066:10161 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.1066      state:D stack:16200 pid:10161 tgid:10160 ppid:9403   task_flags:0x440140 flags:0x00004006
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_timeout+0x12b/0x270
 __closure_sync_timeout+0x282/0x3a0
 __bch2_wait_on_allocator+0x112/0x240
 __bch2_write+0x31ef/0x3900
 __bch2_writepage+0x1536/0x2790
 write_cache_pages+0x64/0x100
 bch2_writepages+0xf9/0x2d0
 do_writepages+0x32e/0x550
 file_write_and_wait_range+0x23e/0x340
 bch2_fsync+0x127/0x330
 bch2_write_iter+0x2822/0x2b90
 vfs_write+0x5c9/0xb30
 ksys_write+0x145/0x250
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb7c638ec29
RSP: 002b:00007fb7c72cf038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fb7c65d5fa0 RCX: 00007fb7c638ec29
RDX: 000000000208e24b RSI: 0000200000000000 RDI: 0000000000000006
RBP: 00007fb7c6411e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb7c65d6038 R14: 00007fb7c65d5fa0 R15: 00007ffc81483968
 </TASK>

Showing all locks held in the system:
2 locks held by kworker/0:1/10:
1 lock held by ksoftirqd/0/15:
1 lock held by khungtaskd/34:
 #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5677:
 #0: ffff88810f5b50a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029062f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
3 locks held by kworker/u9:21/8850:
 #0: ffff88801abff948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000666fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff88803fd420e0 (&type->s_umount_key#62){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0
2 locks held by syz.7.1066/10161:
 #0: ffff88810594bcf8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x247/0x320
 #1: ffff88803fd42428 (sb_writers#18){.+.+}-{0:0}, at: vfs_write+0x211/0xb30
4 locks held by kworker/0:3/18590:
2 locks held by syz.6.3434/18814:
1 lock held by syz.4.3439/18842:
 #0: ffffffff8f53a1c8 (rtnl_mutex){+.+.}-{4:4}, at: dev_ethtool+0x1d0/0x19b0
1 lock held by syz.5.3442/18860:
4 locks held by syz.6.3443/18863:
 #0: ffffffff8f59f7f0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f53a1c8 (rtnl_mutex){+.+.}-{4:4}, at: nl80211_pre_doit+0x5f/0x930
 #2: ffff888011758768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: ieee80211_stop+0x126/0x240
 #3: ffffffff8e13fb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 34 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250
 nmi_cpu_backtrace+0x39e/0x3d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 watchdog+0xf93/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5775 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:unwind_next_frame+0x130e/0x2390
Code: c1 e8 3f 48 01 c8 48 83 e0 fe 4c 8d 3c 45 00 00 00 00 49 01 ef 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 <84> c0 75 27 49 63 07 4c 01 f8 49 8d 4f 04 4c 39 e0 48 0f 46 e9 49
RSP: 0018:ffffc90000006a78 EFLAGS: 00000a06
RAX: 0000000000000000 RBX: ffffffff9011a208 RCX: dffffc0000000000
RDX: ffffffff9011a208 RSI: ffffffff90bab52a RDI: ffffffff8be33f20
RBP: ffffffff9011a208 R08: 0000000000000001 R09: ffffffff8172c195
R10: ffffc90000006b98 R11: ffffffff81ac3b00 R12: ffffffff896325fc
R13: ffffffff9011a208 R14: ffffc90000006b48 R15: ffffffff9011a208
FS:  000055558d412500(0000) GS:ffff8880b8613000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5e6d1b8bd0 CR3: 00000000246fc000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 save_stack+0xf5/0x1f0
 __set_page_owner+0x8d/0x4a0
 post_alloc_hook+0x240/0x2a0
 get_page_from_freelist+0x21e4/0x22c0
 __alloc_frozen_pages_noprof+0x181/0x370
 alloc_pages_mpol+0x232/0x4a0
 allocate_slab+0x8a/0x370
 ___slab_alloc+0xbeb/0x1420
 kmem_cache_alloc_noprof+0x283/0x3c0
 skb_clone+0x212/0x3a0
 vxcan_xmit+0x1f8/0x780
 dev_hard_start_xmit+0x2d7/0x830
 __dev_queue_xmit+0x1b8d/0x3b50
 can_send+0x905/0xd00
 can_can_gw_rcv+0xc45/0xf20
 can_rcv_filter+0x126/0x7d0
 can_receive+0x312/0x450
 canfd_rcv+0x145/0x270
 __netif_receive_skb+0x164/0x380
 process_backlog+0x60e/0x14f0
 __napi_poll+0xc7/0x360
 net_rx_action+0x707/0xe30
 handle_softirqs+0x286/0x870
 do_softirq+0xec/0x180
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x17d/0x1c0
 tcp_recvmsg+0x1fa/0x810
 inet_recvmsg+0x147/0x250
 sock_recvmsg+0x1a8/0x270
 sock_read_iter+0x231/0x2f0
 vfs_read+0x55a/0xa30
 ksys_read+0x145/0x250
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f046878d5fd
Code: a8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb b5 e8 a8 48 00 00 0f 1f 84 00 00 00 00 00 80 3d 61 af 21 00 00 74 17 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 5b c3 66 2e 0f 1f 84 00 00 00 00 00 48 83 ec
RSP: 002b:00007ffdc40dee68 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f046878d5fd
RDX: 0000000000000004 RSI: 00007ffdc40dee7c RDI: 0000000000000003
RBP: 0000000000000000 R08: 000000002e961a1d R09: 7fffffffffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffdc40df290
R13: 0000000000000004 R14: 00007ffdc40dee7c R15: 00007ffdc40def10
 </TASK>
