INFO: task syz-executor:5823 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21976 pid:5823 tgid:5823 ppid:1 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x169e/0x54f0 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0x164/0x360 kernel/sched/core.c:7282 fuse_chan_wait_aborted+0x15b/0x250 fs/fuse/dev.c:2212 fuse_conn_destroy+0x1e7/0x3e0 fs/fuse/inode.c:1969 fuse_sb_destroy fs/fuse/inode.c:1988 [inline] fuse_kill_sb_anon+0x1ef/0x270 fs/fuse/inode.c:2001 deactivate_locked_super+0xbc/0x130 fs/super.c:476 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:328 [inline] do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f779416da57 RSP: 002b:00007fff72ee90e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f7794202048 RCX: 00007f779416da57 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff72ee91a0 RBP: 00007fff72ee91a0 R08: 00007fff72eea1a0 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff72eea230 R13: 00007f7794202048 R14: 000000000003422b R15: 00007fff72eea270 Showing all locks held in the system: 1 lock held by khungtaskd/39: #0: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6777 2 locks held by getty/5578: #0: ffff88803734c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003cbe2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211 1 lock held by syz-executor/5823: #0: ffff8880298520d0 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880298520d0 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff8880298520d0 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 1 lock held by syz.0.1193/8630: #0: ffff8880298520d0 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff8880298520d0 (&type->s_umount_key#52){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 3 locks held by syz.7.2143/11527: #0: ffff88803a1c2480 (sb_writers#5){.+.+}-{0:0}, at: do_coredump fs/coredump.c:1132 [inline] #0: ffff88803a1c2480 (sb_writers#5){.+.+}-{0:0}, at: vfs_coredump+0x380d/0x4540 fs/coredump.c:1206 #1: ffff88805e9da8e0 (&sb->s_type->i_mutex_key#15){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline] #1: ffff88805e9da8e0 (&sb->s_type->i_mutex_key#15){+.+.}-{4:4}, at: shmem_file_write_iter+0x82/0x120 mm/shmem.c:3468 #2: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #2: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #2: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: get_mem_cgroup_from_mm+0x38/0x2d0 mm/memcontrol.c:1131 2 locks held by syz.7.2153/11543: #0: ffff88803a95c4b0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:536 [inline] #0: ffff88803a95c4b0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x2c2/0x9e0 mm/mmap.c:1308 #1: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #1: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #1: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1181 [inline] #1: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xa6/0x2550 arch/x86/kernel/unwind_orc.c:495 1 lock held by syz.3.2162/11563: #0: ffff88803a95d1b0 (&mm->mmap_lock){++++}-{4:4}, at: __might_fault+0xaf/0x130 mm/memory.c:7324 4 locks held by syz.1.2163/11564: #0: ffffffff8e4cb478 (pcpu_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #0: ffffffff8e4cb478 (pcpu_lock){+.+.}-{3:3}, at: free_percpu+0x24c/0xf30 mm/percpu.c:2249 #1: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #1: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #1: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #1: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57 #2: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #2: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #2: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: pcpu_memcg_free_hook mm/percpu.c:1669 [inline] #2: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: free_percpu+0x33f/0xf30 mm/percpu.c:2261 #3: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #3: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #3: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: get_non_dying_memcg_start mm/memcontrol.c:813 [inline] #3: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: mod_memcg_state+0x3f/0x1a0 mm/memcontrol.c:871 4 locks held by syz.6.2164/11567: #0: ffff88803992aab0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:592 [inline] #0: ffff88803992aab0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x194/0x9e0 mm/mmap.c:1284 #1: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #1: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #1: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x200 mm/pgtable-generic.c:290 #2: ffff8880595c5f58 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #2: ffff8880595c5f58 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: pte_offset_map_lock+0x13d/0x210 mm/pgtable-generic.c:404 #3: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #3: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #3: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #3: ffffffff8e3c8100 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 39 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd3/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5181 Comm: klogd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline] RIP: 0010:write_comp_data kernel/kcov.c:245 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x8/0xa0 kernel/kcov.c:321 Code: 74 0a 18 48 89 44 0a 20 c3 cc cc cc cc cc 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0d f8 8b f6 10 65 44 8b 05 18 8c f6 10 41 81 e0 00 00 ff RSP: 0018:ffffc900049e75c8 EFLAGS: 00000046 RAX: ffffffff8168de4b RBX: ffff888011f4d6c6 RCX: ffff888011f48000 RDX: 0000000040000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: fffffbfff1f9e2ff R12: 0000000000080000 R13: dffffc0000000000 R14: ffff888011f48000 R15: 0000000000000000 FS: 00007f6a0558ac80(0000) GS:ffff888125a68000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00002000000000c0 CR3: 0000000011b3a000 CR4: 00000000003526f0 DR0: 0000000000000008 DR1: 0000000000000002 DR2: 0000000000000081 DR3: ffffffffefffff14 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: switch_to_extra arch/x86/kernel/process.h:36 [inline] __switch_to+0x60b/0x1410 arch/x86/kernel/process_64.c:676 context_switch kernel/sched/core.c:5387 [inline] __schedule+0x169e/0x54f0 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0x164/0x360 kernel/sched/core.c:7282 schedule_timeout+0xc3/0x2c0 kernel/time/sleep_timeout.c:75 unix_wait_for_peer+0x1f5/0x2f0 net/unix/af_unix.c:1622 unix_dgram_sendmsg+0xb73/0x18d0 net/unix/af_unix.c:2251 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] __sys_sendto+0x67f/0x710 net/socket.c:2265 __do_sys_sendto net/socket.c:2272 [inline] __se_sys_sendto net/socket.c:2268 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2268 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6a056da407 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:00007ffdb7dceb60 EFLAGS: 00000202 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f6a0558ac80 RCX: 00007f6a056da407 RDX: 0000000000000054 RSI: 00007ffdb7dceca0 RDI: 0000000000000003 RBP: 00007ffdb7dcf0d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000004000 R11: 0000000000000202 R12: 00007ffdb7dcf0e8 R13: 00007ffdb7dceca0 R14: 0000000000000039 R15: 00007ffdb7dceca0