INFO: task syz-executor.0:5092 blocked for more than 143 seconds. Not tainted 6.7.0-rc6-syzkaller-00010-g2cf4f94d8e86 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:20400 pid:5092 tgid:5092 ppid:1 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5376 [inline] __schedule+0x1961/0x4ab0 kernel/sched/core.c:6688 __schedule_loop kernel/sched/core.c:6763 [inline] schedule+0x149/0x260 kernel/sched/core.c:6778 wb_wait_for_completion+0x166/0x290 fs/fs-writeback.c:192 sync_inodes_sb+0x293/0xb20 fs/fs-writeback.c:2758 sync_filesystem+0x16f/0x220 fs/sync.c:64 generic_shutdown_super+0x72/0x2c0 fs/super.c:669 kill_block_super+0x44/0x90 fs/super.c:1667 ext4_kill_sb+0x68/0xa0 fs/ext4/super.c:7330 deactivate_locked_super+0xc1/0x130 fs/super.c:484 cleanup_mnt+0x426/0x4c0 fs/namespace.c:1256 task_work_run+0x24a/0x300 kernel/task_work.c:180 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:171 exit_to_user_mode_prepare+0xb1/0x150 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x69/0x2a0 kernel/entry/common.c:296 do_syscall_64+0x52/0x110 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x63/0x6b RIP: 0033:0x7f532367ded7 RSP: 002b:00007fffe8417bd8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f532367ded7 RDX: 0000000000000000 RSI: 000000000000000a RDI: 00007fffe8417c90 RBP: 00007fffe8417c90 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fffe8418d50 R13: 00007f53236c73b9 R14: 00000000002715f2 R15: 0000000000000016 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8d92dae0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:301 [inline] #0: ffffffff8d92dae0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline] #0: ffffffff8d92dae0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614 4 locks held by kworker/u4:4/58: 2 locks held by kworker/u4:5/141: 2 locks held by getty/4818: #0: ffff88802a0b10a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900031332f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b4/0x1e10 drivers/tty/n_tty.c:2201 2 locks held by syz-executor.0/5092: #0: ffff8880364500e0 (&type->s_umount_key#30){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff8880364500e0 (&type->s_umount_key#30){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff8880364500e0 (&type->s_umount_key#30){++++}-{3:3}, at: deactivate_super+0xad/0xf0 fs/super.c:516 #1: ffff888146e847d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline] #1: ffff888146e847d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x274/0xb20 fs/fs-writeback.c:2756 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.7.0-rc6-syzkaller-00010-g2cf4f94d8e86 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x498/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x310 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+0xfaf/0xff0 kernel/hung_task.c:379 kthread+0x2d3/0x370 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 11962 Comm: kworker/u4:8 Not tainted 6.7.0-rc6-syzkaller-00010-g2cf4f94d8e86 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 Workqueue: bat_events batadv_nc_worker RIP: 0010:__kasan_check_read+0xa/0x20 mm/kasan/shadow.c:31 Code: 48 c7 c7 11 fa 12 8d 48 89 de eb 0a 48 c7 c7 43 fa 12 8d 4c 89 fe e8 d5 14 2a 09 31 db eb d4 90 f3 0f 1e fa 89 f6 48 8b 0c 24 <31> d2 e9 bf ea ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 RSP: 0018:ffffc9001580f928 EFLAGS: 00000006 RAX: 000000000000001b RBX: 00000000000006ce RCX: ffffffff816d2768 RDX: 000000004fe8219a RSI: 0000000000000008 RDI: ffffffff90dd7438 RBP: 0e82cb65aa2612b0 R08: ffffffff90dd7367 R09: 1ffffffff21bae6c R10: dffffc0000000000 R11: fffffbfff21bae6d R12: ffff888022ad0000 R13: ffff888022ad0000 R14: 0000000000000000 R15: ffff888022ad0000 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055bbf90f4680 CR3: 0000000028ea4000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read include/linux/instrumented.h:68 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] hlock_class kernel/locking/lockdep.c:228 [inline] __lock_acquire+0xf18/0x1fd0 kernel/locking/lockdep.c:5133 lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754 rcu_lock_acquire include/linux/rcupdate.h:301 [inline] rcu_read_lock include/linux/rcupdate.h:747 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0xec/0x610 net/batman-adv/network-coding.c:719 process_one_work kernel/workqueue.c:2627 [inline] process_scheduled_works+0x90f/0x1420 kernel/workqueue.c:2700 worker_thread+0xa5f/0x1000 kernel/workqueue.c:2781 kthread+0x2d3/0x370 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242