INFO: task syz.0.240:6875 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.240 state:D stack:26056 pid:6875 tgid:6873 ppid:5856 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5360 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6964 __schedule_loop kernel/sched/core.c:7046 [inline] schedule+0x165/0x360 kernel/sched/core.c:7061 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7118 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760 bdev_open+0xe0/0xd30 block/bdev.c:945 blkdev_open+0x457/0x600 block/fops.c:694 do_dentry_open+0x953/0x13f0 fs/open.c:965 vfs_open+0x3b/0x340 fs/open.c:1095 do_open fs/namei.c:3895 [inline] path_openat+0x2ee5/0x3830 fs/namei.c:4054 do_filp_open+0x1fa/0x410 fs/namei.c:4081 do_sys_openat2+0x121/0x1c0 fs/open.c:1435 do_sys_open fs/open.c:1450 [inline] __do_sys_openat fs/open.c:1466 [inline] __se_sys_openat fs/open.c:1461 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1461 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8a0d58d510 RSP: 002b:00007f8a0e3a6b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f8a0d58d510 RDX: 0000000000000000 RSI: 00007f8a0e3a6c10 RDI: 00000000ffffff9c RBP: 00007f8a0e3a6c10 R08: 0000000000000000 R09: 002364626e2f7665 R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd R13: 00007f8a0d7d6038 R14: 00007f8a0d7d5fa0 R15: 00007ffd51252d58 Showing all locks held in the system: 2 locks held by kworker/1:0/24: #0: ffff88801a871548 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88801a871548 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc900001e7ba0 ((work_completion)(&fw_work->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc900001e7ba0 ((work_completion)(&fw_work->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 1 lock held by khungtaskd/31: #0: ffffffff8e53c820 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e53c820 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e53c820 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/1:2/2151: #0: ffff88801a871548 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88801a871548 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc900055c7ba0 ((work_completion)(&fw_work->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc900055c7ba0 ((work_completion)(&fw_work->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 2 locks held by getty/5631: #0: ffff8880346c00a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000333b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 1 lock held by udevd/5860: #0: ffff888025b2e358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945 1 lock held by syz-executor/5861: #0: ffff8880b8639f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:636 3 locks held by kworker/1:6/5958: #0: ffff88801a871548 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88801a871548 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc9000516fba0 ((work_completion)(&fw_work->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc9000516fba0 ((work_completion)(&fw_work->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8e3e2a70 (umhelper_sem){++++}-{4:4}, at: usermodehelper_read_lock_wait+0xff/0x210 kernel/umh.c:246 1 lock held by syz.0.240/6875: #0: ffff888025b2e358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945 4 locks held by syz.5.1163/10180: #0: ffff88807ce831c0 (&tty->legacy_mutex){+.+.}-{4:4}, at: __tty_hangup+0xe8/0x680 drivers/tty/tty_io.c:581 #1: ffff88807ce830a0 (&tty->ldisc_sem){++++}-{0:0}, at: __tty_ldisc_lock drivers/tty/tty_ldisc.c:289 [inline] #1: ffff88807ce830a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock+0x6c/0xc0 drivers/tty/tty_ldisc.c:313 #2: ffffffff8f955108 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f955108 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2142 #3: ffffffff8e5422b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #3: ffffffff8e5422b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957 2 locks held by syz.2.1165/10186: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0xf60/0xfa0 kernel/hung_task.c:495 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 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: 10186 Comm: syz.2.1165 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:lockdep_hardirqs_on+0x6/0x150 kernel/locking/lockdep.c:4416 Code: 90 90 90 e9 0c e8 02 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 56 <53> 48 83 ec 10 65 48 8b 05 9d 0d 5c 07 48 89 44 24 08 65 48 8b 1c RSP: 0018:ffffc9000451ee28 EFLAGS: 00000082 RAX: 9412539c91b08000 RBX: 0000000000000000 RCX: 9412539c91b08000 RDX: 0000000000000000 RSI: ffffffff8de9418e RDI: ffffffff81916a26 RBP: ffffc9000451ee90 R08: ffffffff8fe53a37 R09: 1ffffffff1fca746 R10: dffffc0000000000 R11: fffffbfff1fca747 R12: ffff8880b8639f80 R13: dffffc0000000000 R14: ffff88807bd08000 R15: ffff8880b863ab58 FS: 0000000000000000(0000) GS:ffff8881257a7000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555566d7f5c8 CR3: 0000000021312000 CR4: 00000000003526f0 Call Trace: raw_spin_rq_unlock_irq kernel/sched/sched.h:1533 [inline] finish_lock_switch kernel/sched/core.c:5108 [inline] finish_task_switch+0x266/0x950 kernel/sched/core.c:5226 context_switch kernel/sched/core.c:5363 [inline] __schedule+0x17a0/0x4cc0 kernel/sched/core.c:6964 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7291 irqentry_exit+0x6f/0x90 kernel/entry/common.c:211 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:kasan_check_range+0x1dc/0x2c0 mm/kasan/generic.c:200 Code: 85 e4 49 0f 49 dc 48 83 e3 f8 49 29 dc 74 12 41 80 3b 00 0f 85 b8 00 00 00 49 ff c3 49 ff cc 75 ee 5b 41 5c 41 5d 41 5e 41 5f <5d> e9 8e f3 69 09 cc 45 84 ff 75 63 41 f7 c7 00 ff 00 00 75 5f 41 RSP: 0018:ffffc9000451f230 EFLAGS: 00000256 RAX: ffffffff8202cd01 RBX: ffffea0001639440 RCX: ffffffff8202cd8c RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffea0001639440 RBP: 0000000000020000 R08: ffffea0001639447 R09: 1ffffd40002c7288 R10: dffffc0000000000 R11: fffff940002c7289 R12: 1ffffd40002c7289 R13: 1ffffd40002c7288 R14: 0000000000000000 R15: dffffc0000000000 instrument_atomic_read include/linux/instrumented.h:68 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] folio_test_swapcache include/linux/page-flags.h:637 [inline] folio_mapping+0x10c/0x1f0 mm/util.c:699 folio_needs_release mm/internal.h:521 [inline] truncate_cleanup_folio+0x115/0x430 mm/truncate.c:159 truncate_inode_folio+0x55/0x70 mm/truncate.c:175 shmem_undo_range+0x3a9/0x14b0 mm/shmem.c:1116 shmem_truncate_range mm/shmem.c:1232 [inline] shmem_evict_inode+0x272/0xa70 mm/shmem.c:1360 evict+0x504/0x9c0 fs/inode.c:810 __dentry_kill+0x209/0x660 fs/dcache.c:669 dput+0x19f/0x2b0 fs/dcache.c:911 __fput+0x68e/0xa70 fs/file_table.c:476 task_work_run+0x1d4/0x260 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x6b5/0x2300 kernel/exit.c:966 do_group_exit+0x21c/0x2d0 kernel/exit.c:1107 get_signal+0x1286/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:40 [inline] exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] irqentry_exit_to_user_mode+0x81/0x120 kernel/entry/common.c:73 exc_page_fault+0xab/0x100 arch/x86/mm/fault.c:1535 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7faa9f38ebb1 Code: Unable to access opcode bytes at 0x7faa9f38eb87. RSP: 002b:fffffffffffffea0 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007faa9f5d5fa0 RCX: 00007faa9f38eba9 RDX: 0000000000000000 RSI: fffffffffffffea0 RDI: 0000000000000000 RBP: 00007faa9f411e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007faa9f5d6038 R14: 00007faa9f5d5fa0 R15: 00007ffe78b74958