INFO: task syz-executor.4:27174 blocked for more than 143 seconds. Not tainted 6.6.0-rc3-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:24464 pid:27174 ppid:5091 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0xee1/0x5a10 kernel/sched/core.c:6695 schedule+0xe7/0x1b0 kernel/sched/core.c:6771 io_schedule+0xbe/0x130 kernel/sched/core.c:9026 folio_wait_bit_common+0x3dc/0x9c0 mm/filemap.c:1301 folio_wait_writeback+0x3b/0x250 mm/page-writeback.c:3068 __filemap_fdatawait_range+0x117/0x220 mm/filemap.c:525 filemap_write_and_wait_range mm/filemap.c:687 [inline] filemap_write_and_wait_range+0xe3/0x120 mm/filemap.c:669 direct_write_fallback+0xb3/0x150 fs/libfs.c:1900 __generic_file_write_iter+0x1e1/0x240 mm/filemap.c:4060 generic_file_write_iter+0xe3/0x350 mm/filemap.c:4090 call_write_iter include/linux/fs.h:1956 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x650/0xe40 fs/read_write.c:584 ksys_write+0x12f/0x250 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f93f767cae9 RSP: 002b:00007f93f84ba0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f93f779bf80 RCX: 00007f93f767cae9 RDX: 0000000002007ffb RSI: 0000000020000040 RDI: 0000000000000004 RBP: 00007f93f76c847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f93f779bf80 R15: 00007fffc482ec08 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8cbab2a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:303 [inline] #0: ffffffff8cbab2a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:749 [inline] #0: ffffffff8cbab2a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6613 2 locks held by getty/4789: #0: ffff88802aeba0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3} , at: n_tty_read+0xfc5/0x1480 drivers/tty/n_tty.c:2206 2 locks held by kworker/u4:18/18440: 3 locks held by syz-executor.4/27174: #0: ffff88802a5ae5c8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe7/0x170 fs/file.c:1064 #1: ffff888060d02410 (sb_writers#18){.+.+}-{0:0}, at: ksys_write+0x12f/0x250 fs/read_write.c:637 #2: ffff888084c8f5f8 (&sb->s_type->i_mutex_key#25){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:802 [inline] #2: ffff888084c8f5f8 (&sb->s_type->i_mutex_key#25){+.+.}-{3:3}, at: generic_file_write_iter+0x92/0x350 mm/filemap.c:4087 3 locks held by syz-executor.0/32019: #0: ffff88808dd29410 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:802 [inline] #0: ffff88808dd29410 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: __sock_release+0x86/0x260 net/socket.c:658 #1: ffff8880844d3130 (sk_lock-AF_PPPOX){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1722 [inline] ffff8880844d3130 (sk_lock-AF_PPPOX){+.+.}-{0:0}, at: pptp_release+0x53/0x280 drivers/net/ppp/pptp.c:508 #2: ffffffff8cbb6b78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:293 [inline] #2: ffffffff8cbb6b78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x69e/0x7e0 kernel/rcu/tree_exp.h:992 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted 6.6.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x277/0x380 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x299/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf87/0x1210 kernel/hung_task.c:379 kthread+0x33c/0x440 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 18431 Comm: kworker/u4:15 Not tainted 6.6.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023 Workqueue: bat_events batadv_purge_orig RIP: 0010:__lock_acquire+0x300/0x5de0 kernel/locking/lockdep.c:5072 Code: 45 10 48 89 c2 48 89 44 24 58 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 6d 3e 00 00 49 8d 45 18 4d 89 55 10 <48> 89 c2 48 89 44 24 50 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 RSP: 0018:ffffc9000329f918 EFLAGS: 00000046 RAX: ffff88803ebbe470 RBX: 00000000000006f2 RCX: 1ffff11007d77c8f RDX: 1ffff11007d77c8d RSI: 00000000000006f1 RDI: ffff88803ebbe460 RBP: 0000000000000000 R08: 1ffff11007d77c8a R09: 0000000000000001 R10: ffff88803e8d4818 R11: 0000000000000000 R12: 0000000000000000 R13: ffff88803ebbe458 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5717178038 CR3: 000000000c976000 CR4: 0000000000350ef0 Call Trace: lock_acquire kernel/locking/lockdep.c:5753 [inline] lock_acquire+0x1ae/0x510 kernel/locking/lockdep.c:5718 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x33/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] batadv_purge_orig_ref+0x16d/0x1520 net/batman-adv/originator.c:1243 batadv_purge_orig+0x19/0x60 net/batman-adv/originator.c:1272 process_one_work+0x884/0x15c0 kernel/workqueue.c:2630 process_scheduled_works kernel/workqueue.c:2703 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784 kthread+0x33c/0x440 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304