INFO: task syz-executor:5782 blocked for more than 143 seconds. Not tainted 6.6.101-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:20936 pid:5782 ppid:1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 wb_wait_for_completion+0x166/0x290 fs/fs-writeback.c:192 sync_inodes_sb+0x1bc/0x9e0 fs/fs-writeback.c:2761 sync_filesystem+0x171/0x220 fs/sync.c:64 generic_shutdown_super+0x6f/0x2b0 fs/super.c:666 kill_block_super+0x44/0x90 fs/super.c:1660 deactivate_locked_super+0x97/0x100 fs/super.c:481 cleanup_mnt+0x429/0x4c0 fs/namespace.c:1250 task_work_run+0x1ce/0x250 kernel/task_work.c:239 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7efcda38ff17 RSP: 002b:00007ffe35c1a1a8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000064 RCX: 00007efcda38ff17 RDX: 0000000000000200 RSI: 0000000000000009 RDI: 00007ffe35c1b350 RBP: 00007efcda411c05 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffe35c1b350 R13: 00007efcda411c05 R14: 00005555854794a8 R15: 00007ffe35c1c420 Showing all locks held in the system: 1 lock held by khungtaskd/28: #0: ffffffff8cd2fba0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8cd2fba0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8cd2fba0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 5 locks held by kworker/u4:4/59: 2 locks held by kworker/u4:7/1319: 2 locks held by getty/5545: #0: ffff88823bd008a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217 2 locks held by syz-executor/5782: #0: ffff88805f71c0e0 (&type->s_umount_key#61){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff88805f71c0e0 (&type->s_umount_key#61){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88805f71c0e0 (&type->s_umount_key#61){+.+.}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513 #1: ffff8880213427d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline] #1: ffff8880213427d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1a0/0x9e0 fs/fs-writeback.c:2759 2 locks held by syz.3.407/7751: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.6.101-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 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+0xf41/0xf80 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5146 Comm: klogd Not tainted 6.6.101-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:__x64_sys_sendto+0xb0/0xf0 net/socket.c:2209 Code: 74 05 e8 73 0e 7d f9 4c 8b 6b 38 48 8d 7b 48 48 89 f8 48 c1 e8 03 42 80 3c 30 00 74 05 e8 58 0e 7d f9 48 8b 6b 48 48 83 c3 40 <48> 89 d8 48 c1 e8 03 42 80 3c 30 00 74 08 48 89 df e8 3a 0e 7d f9 RSP: 0018:ffffc90003287ee0 EFLAGS: 00000282 RAX: 1ffff92000650ff4 RBX: ffffc90003287f98 RCX: ffff88807d111e00 RDX: 0000000000000000 RSI: 000000000000002c RDI: ffffc90003287fa0 RBP: 0000000000000000 R08: ffffffff8e4a84ef R09: 1ffffffff1c9509d R10: dffffc0000000000 R11: fffffbfff1c9509e R12: 0000000000000049 R13: 0000000000004000 R14: dffffc0000000000 R15: 00007fff5693cba0 FS: 00007fa35c513c80(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2d5e420000 CR3: 0000000030a62000 CR4: 00000000003506f0 Call Trace: do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fa35c663407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007fff5693ca60 EFLAGS: 00000202 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007fa35c513c80 RCX: 00007fa35c663407 RDX: 0000000000000049 RSI: 00007fff5693cba0 RDI: 0000000000000003 RBP: 00007fff5693cfd0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000004000 R11: 0000000000000202 R12: 00007fff5693cfe8 R13: 00007fff5693cba0 R14: 000000000000002e R15: 00007fff5693cba0