INFO: task syz.3.537:6016 blocked for more than 144 seconds.
      Not tainted 5.15.167-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.537       state:D stack:28256 pid: 6016 ppid:  5584 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5027 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373
 schedule+0x11b/0x1f0 kernel/sched/core.c:6456
 wb_wait_for_completion+0x164/0x290 fs/fs-writeback.c:191
 sync_inodes_sb+0x293/0xab0 fs/fs-writeback.c:2770
 iterate_supers+0x127/0x1e0 fs/super.c:716
 ksys_sync+0xb9/0x1c0 fs/sync.c:102
 __do_sys_sync+0xa/0x10 fs/sync.c:113
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fabdd203ef9
RSP: 002b:00007fabdb65b038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fabdd3bc058 RCX: 00007fabdd203ef9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fabdd276b76 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007fabdd3bc058 R15: 00007ffeca0b0928
 </TASK>
INFO: task syz.3.537:6018 blocked for more than 145 seconds.
      Not tainted 5.15.167-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.537       state:D stack:28256 pid: 6018 ppid:  5584 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5027 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373
 schedule+0x11b/0x1f0 kernel/sched/core.c:6456
 rwsem_down_write_slowpath+0xf0c/0x16a0 kernel/locking/rwsem.c:1165
 bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
 sync_inodes_sb+0x274/0xab0 fs/fs-writeback.c:2768
 iterate_supers+0x127/0x1e0 fs/super.c:716
 ksys_sync+0xb9/0x1c0 fs/sync.c:102
 __do_sys_sync+0xa/0x10 fs/sync.c:113
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fabdd203ef9
RSP: 002b:00007fabdb63a038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fabdd3bc130 RCX: 00007fabdd203ef9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fabdd276b76 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fabdd3bc130 R15: 00007ffeca0b0928
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/1:0/21:
 #0: ffff8880b903a318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xa8/0x140 kernel/sched/core.c:483
 #1: ffffffff8c91fc60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311
 #2: ffffc900039bf098 (&rb->spinlock){..-.}-{2:2}, at: __bpf_ringbuf_reserve+0x1f8/0x600 kernel/bpf/ringbuf.c:328
1 lock held by khungtaskd/27:
 #0: ffffffff8c91fc60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3326:
 #0: ffff888029a0e098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc9000272c2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158
2 locks held by kworker/0:6/3615:
 #0: ffff888017072138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc90003017d20 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
2 locks held by kworker/u4:7/3697:
 #0: ffff88801a782138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc90003087d20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
1 lock held by syz.4.19/3720:
 #0: ffff888077f8e460 (sb_writers#5){.+.+}-{0:0}, at: vfs_writev fs/read_write.c:927 [inline]
 #0: ffff888077f8e460 (sb_writers#5){.+.+}-{0:0}, at: do_pwritev+0x1fd/0x360 fs/read_write.c:1025
1 lock held by syz.3.48/3840:
 #0: ffff88807596c460 (sb_writers#5){.+.+}-{0:0}, at: vfs_writev fs/read_write.c:927 [inline]
 #0: ffff88807596c460 (sb_writers#5){.+.+}-{0:0}, at: do_pwritev+0x1fd/0x360 fs/read_write.c:1025
4 locks held by kworker/u4:16/4249:
 #0: ffff8880171d5938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc90003207d20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
 #2: ffffffff8da261d0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xf1/0xb60 net/core/net_namespace.c:561
 #3: ffffffff8c924130 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x9c/0x4e0 kernel/rcu/tree.c:4039
2 locks held by syz.3.537/6016:
 #0: ffff888077f8e0e0 (&type->s_umount_key#32){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:714
 #1: ffff8881475be7d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
 #1: ffff8881475be7d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x274/0xab0 fs/fs-writeback.c:2768
2 locks held by syz.3.537/6018:
 #0: ffff888077f8e0e0 (&type->s_umount_key#32){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:714
 #1: ffff8881475be7d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
 #1: ffff8881475be7d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x274/0xab0 fs/fs-writeback.c:2768
2 locks held by syz-executor/7260:
 #0: ffffffff8da31d88 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0: ffffffff8da31d88 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x94c/0xee0 net/core/rtnetlink.c:5615
 #1: ffffffff8c924228 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
 #1: ffffffff8c924228 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x280/0x740 kernel/rcu/tree_exp.h:845
2 locks held by syz.1.819/7310:
 #0: ffffffff8da261d0 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x378/0x5d0 net/core/net_namespace.c:472
 #1: ffffffff8da31d88 (rtnl_mutex){+.+.}-{3:3}, at: cangw_pernet_exit+0xe/0x20 net/can/gw.c:1244
1 lock held by syz.4.820/7315:
 #0: ffff888077f8e0e0 (&type->s_umount_key#32){++++}-{3:3}, at: user_get_super+0xd3/0x250 fs/super.c:846
1 lock held by syz.2.825/7335:
 #0: ffffffff8da31d88 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:699 [inline]
 #0: ffffffff8da31d88 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3a/0x1b0 drivers/net/tun.c:3440
1 lock held by syz.2.825/7344:
 #0: ffffffff8da31d88 (rtnl_mutex){+.+.}-{3:3}, at: arp_ioctl+0x27c/0x660 net/ipv4/arp.c:1215

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

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.167-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
 watchdog+0xe72/0xeb0 kernel/hung_task.c:295
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 3840 Comm: syz.3.48 Not tainted 5.15.167-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
RIP: 0010:unwind_next_frame+0x43a/0x1fa0 arch/x86/kernel/unwind_orc.c:461
Code: 89 ec 49 c1 ec 03 41 0f b6 04 14 84 c0 0f 85 33 14 00 00 48 89 d8 48 c1 e8 03 0f b6 04 10 84 c0 0f 85 49 14 00 00 0f b7 45 00 <89> c3 83 e3 0f 0f 84 9b 00 00 00 8d 43 fe 83 f8 07 0f 87 29 01 00
RSP: 0018:ffffc900035b6808 EFLAGS: 00000246
RAX: 0000000000000015 RBX: ffffffff8e6fed4b RCX: ffffffff8e0234e4
RDX: dffffc0000000000 RSI: ffffffff8e6fed46 RDI: ffffffff8e0234e0
RBP: ffffffff8e6fed4a R08: 0000000000000001 R09: ffffc900035b69b0
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffffffff1cdfda9
R13: ffffffff821582f7 R14: ffffffff8e6fed46 R15: ffffc900035b68c0
FS:  00007f5ea85616c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2894583d58 CR3: 00000000228b2000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 arch_stack_walk+0x10d/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 ____kasan_kmalloc+0xba/0xf0 mm/kasan/common.c:513
 kasan_kmalloc include/linux/kasan.h:264 [inline]
 __kmalloc+0x168/0x300 mm/slub.c:4407
 kmalloc_array include/linux/slab.h:631 [inline]
 kcalloc include/linux/slab.h:660 [inline]
 ext4_find_extent+0x368/0xdd0 fs/ext4/extents.c:907
 ext4_ext_map_blocks+0x2da/0x7630 fs/ext4/extents.c:4144
 ext4_map_blocks+0xa66/0x1c70 fs/ext4/inode.c:672
 mpage_map_one_extent fs/ext4/inode.c:2407 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2460 [inline]
 ext4_writepages+0x160e/0x3d10 fs/ext4/inode.c:2828
 do_writepages+0x481/0x730 mm/page-writeback.c:2386
 filemap_fdatawrite_wbc+0x1d6/0x230 mm/filemap.c:400
 __filemap_fdatawrite_range mm/filemap.c:433 [inline]
 file_write_and_wait_range+0x1cb/0x2b0 mm/filemap.c:810
 ext4_sync_file+0x225/0xb90 fs/ext4/fsync.c:151
 generic_write_sync include/linux/fs.h:2989 [inline]
 ext4_buffered_write_iter+0x2e5/0x360 fs/ext4/file.c:275
 ext4_file_write_iter+0x87c/0x1990
 do_iter_readv_writev+0x594/0x7a0
 do_iter_write+0x1e6/0x760 fs/read_write.c:855
 vfs_writev fs/read_write.c:928 [inline]
 do_pwritev+0x219/0x360 fs/read_write.c:1025
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f5eaa0e8ef9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f5ea8561038 EFLAGS: 00000246 ORIG_RAX: 0000000000000148
RAX: ffffffffffffffda RBX: 00007f5eaa2a0f80 RCX: 00007f5eaa0e8ef9
RDX: 0000000000000001 RSI: 0000000020000100 RDI: 0000000000000008
RBP: 00007f5eaa15bb76 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000008000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f5eaa2a0f80 R15: 00007ffc52b562a8
 </TASK>