INFO: task syz-executor:5817 blocked for more than 143 seconds. Not tainted syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:22528 pid:5817 tgid:5817 ppid:1 task_flags:0x40014c flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x157c/0x52b0 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0x164/0x360 kernel/sched/core.c:7004 wb_wait_for_completion+0x372/0x690 fs/fs-writeback.c:226 sync_inodes_sb+0x1de/0xbd0 fs/fs-writeback.c:2924 sync_filesystem+0x17a/0x230 fs/sync.c:64 generic_shutdown_super+0x77/0x2d0 fs/super.c:625 kill_block_super+0x44/0x90 fs/super.c:1725 ext4_kill_sb+0x68/0xb0 fs/ext4/super.c:7461 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 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x69b/0x2310 kernel/exit.c:971 do_group_exit+0x21b/0x2d0 kernel/exit.c:1112 __do_sys_exit_group kernel/exit.c:1123 [inline] __se_sys_exit_group kernel/exit.c:1121 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1121 x64_sys_call+0x221a/0x2240 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9db599bf79 RSP: 002b:00007ffee5e01ed8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f9db5a31cbf RCX: 00007f9db599bf79 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000027 R08: 0000000000000000 R09: 00007f9db5a31c3b R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffee5e03190 R13: 00007f9db5a31c3b R14: 000055557996e4e8 R15: 00007ffee5e05350 Showing all locks held in the system: 4 locks held by kworker/0:0/9: #0: ffff8880b863abe0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb6/0x150 kernel/sched/core.c:655 #1: ffff8880b8624588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 #2: ffff88801ebeb160 (&helper->damage_lock){....}-{3:3}, at: drm_fb_helper_fb_dirty drivers/gpu/drm/drm_fb_helper.c:242 [inline] #2: ffff88801ebeb160 (&helper->damage_lock){....}-{3:3}, at: drm_fb_helper_damage_work+0x198/0x750 drivers/gpu/drm/drm_fb_helper.c:274 #3: ffff888025992130 (&dev->master_mutex){+.+.}-{4:4}, at: drm_master_internal_acquire+0x20/0x80 drivers/gpu/drm/drm_auth.c:435 1 lock held by khungtaskd/31: #0: ffffffff8e75e3e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e75e3e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e75e3e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:4/76: 5 locks held by kworker/u8:6/1151: 2 locks held by getty/5568: #0: ffff8880368800a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036bb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211 2 locks held by syz-executor/5817: #0: ffff88807adf20e0 (&type->s_umount_key#33){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88807adf20e0 (&type->s_umount_key#33){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff88807adf20e0 (&type->s_umount_key#33){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffff888026016820 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:397 [inline] #1: ffff888026016820 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x1c2/0xbd0 fs/fs-writeback.c:2922 1 lock held by syz-executor/8198: 1 lock held by syz.5.845/9496: #0: ffff88807adf20e0 (&type->s_umount_key#33){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff88807adf20e0 (&type->s_umount_key#33){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by syz.5.845/9501: #0: ffff88807adf20e0 (&type->s_umount_key#33){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff88807adf20e0 (&type->s_umount_key#33){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 3 locks held by syz-executor/9662: #0: ffffffff90113878 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff90113878 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff90113878 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8fbc4d48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8fbc4d48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8fbc4d48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071 #2: ffffffff8e75e3e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #2: ffffffff8e75e3e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #2: ffffffff8e75e3e0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1193 [inline] #2: ffffffff8e75e3e0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xa5/0x23c0 arch/x86/kernel/unwind_orc.c:495 1 lock held by syz.2.904/9700: #0: ffffffff8e764540 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 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:161 [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:346 [inline] watchdog+0xf90/0xfe0 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 9700 Comm: syz.2.904 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:free_pages_and_swap_cache+0x1e4/0x5b0 mm/swap_state.c:417 Code: db 9f ff 4c 89 e8 48 83 e0 01 0f 85 3f 01 00 00 0f 1f 44 00 00 e8 ec d6 9f ff 48 8b 7c 24 10 e8 c2 f9 ff ff 44 0f b6 6c 24 60 1f 00 00 00 44 89 ee e8 cf d9 9f ff 41 83 fd 1e 0f 87 97 01 00 RSP: 0018:ffffc90003a9f560 EFLAGS: 00000293 RAX: ffffffff8224669b RBX: 000000000000001c RCX: ffff8880367b5ac0 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90003a9f7e8 R08: ffffea0001b30907 R09: 1ffffd4000366120 R10: dffffc0000000000 R11: fffff94000366121 R12: 1ffff1100fa92e1e R13: 000000000000001c R14: ffffea0001b30900 R15: ffff88807d4970f0 FS: 0000000000000000(0000) GS:ffff8881255a0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff7ba747e20 CR3: 000000000e54a000 CR4: 0000000000350ef0 Call Trace: __tlb_batch_free_encoded_pages mm/mmu_gather.c:138 [inline] tlb_batch_pages_flush mm/mmu_gather.c:151 [inline] tlb_flush_mmu_free mm/mmu_gather.c:398 [inline] tlb_flush_mmu+0x6d3/0xa30 mm/mmu_gather.c:405 tlb_finish_mmu+0xf9/0x230 mm/mmu_gather.c:530 exit_mmap+0x453/0xd60 mm/mmap.c:1290 __mmput+0x118/0x430 kernel/fork.c:1174 exit_mm+0x168/0x220 kernel/exit.c:581 do_exit+0x62e/0x2310 kernel/exit.c:959 do_group_exit+0x21b/0x2d0 kernel/exit.c:1112 get_signal+0x1284/0x1330 kernel/signal.c:3034 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0cfe79bf79 Code: Unable to access opcode bytes at 0x7f0cfe79bf4f. RSP: 002b:00007ffc8de2a8e8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f0cfea17da0 RCX: 00007f0cfe79bf79 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f0cfea17da0 R08: 0000000000000006 R09: 0000000000000000 R10: 00007f0cfea17cb0 R11: 0000000000000246 R12: 0000000000069ec2 R13: 00007f0cfea15fac R14: 0000000000069c14 R15: 00007ffc8de2a9f0