INFO: task syz.5.1377:10555 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.1377 state:D stack:26184 pid:10555 ppid:9828 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x6b7/0xcc0 kernel/locking/mutex.c:747 sync_bdevs+0x1af/0x330 block/bdev.c:1076 ksys_sync+0xba/0x150 fs/sync.c:105 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 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: 0033:0x7f4af738f749 RSP: 002b:00007f4af81eb038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f4af75e5fa0 RCX: 00007f4af738f749 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f4af75e5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4af75e6038 R14: 00007f4af75e5fa0 R15: 00007ffce103c808 INFO: task syz.5.1377:10559 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.1377 state:D stack:29128 pid:10559 ppid:9828 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x6b7/0xcc0 kernel/locking/mutex.c:747 sync_bdevs+0x1af/0x330 block/bdev.c:1076 ksys_sync+0xba/0x150 fs/sync.c:105 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 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: 0033:0x7f4af738f749 RSP: 002b:00007f4af81ca038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f4af75e6090 RCX: 00007f4af738f749 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f4af75e6090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4af75e6128 R14: 00007f4af75e6090 R15: 00007ffce103c808 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by getty/5528: #0: ffff8880205080a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217 1 lock held by udevd/5782: #0: ffff88814179e4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:805 1 lock held by syz.5.1377/10555: #0: ffff88814179e4c8 (&disk->open_mutex){+.+.}-{3:3}, at: sync_bdevs+0x1af/0x330 block/bdev.c:1076 1 lock held by syz.5.1377/10559: #0: ffff88814179e4c8 (&disk->open_mutex){+.+.}-{3:3}, at: sync_bdevs+0x1af/0x330 block/bdev.c:1076 1 lock held by syz.9.1759/11877: #0: ffffffff8cd357c0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:4089 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 11893 Comm: syz.0.1762 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:check_region_inline mm/kasan/generic.c:169 [inline] RIP: 0010:kasan_check_range+0x12/0x290 mm/kasan/generic.c:187 Code: 0f 0b b8 ea ff ff ff c3 0f 0b b8 ea ff ff ff c3 cc cc cc cc cc cc cc cc 66 0f 1f 00 b0 01 48 85 f6 0f 84 b8 01 00 00 55 41 57 <41> 56 41 55 41 54 53 4c 8d 04 37 49 39 f8 0f 82 5a 02 00 00 49 89 RSP: 0018:ffffc9000b32f0e0 EFLAGS: 00000002 RAX: ffffffff81b90a01 RBX: 1ffffd400026ca29 RCX: ffffffff81b90a9e RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffea0001365140 RBP: ffffc9000b32f250 R08: ffffc9000b32f1e7 R09: 1ffff92001665e3c R10: dffffc0000000000 R11: fffff52001665e3d R12: ffffea0001365148 R13: ffff88801c7d0000 R14: 0000000000000003 R15: ffffea0001365140 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe2ec7a7f98 CR3: 000000000cb30000 CR4: 00000000003506e0 Call Trace: instrument_atomic_read include/linux/instrumented.h:68 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] folio_test_swapbacked include/linux/page-flags.h:515 [inline] folio_is_file_lru include/linux/mm_inline.h:29 [inline] lru_gen_update_size+0x7e/0xe90 include/linux/mm_inline.h:177 lru_gen_del_folio+0x323/0x6d0 include/linux/mm_inline.h:287 lruvec_del_folio include/linux/mm_inline.h:350 [inline] release_pages+0x9a9/0x2220 mm/swap.c:1012 __folio_batch_release+0x71/0xe0 mm/swap.c:1042 folio_batch_release include/linux/pagevec.h:83 [inline] shmem_undo_range+0x5d0/0x1a40 mm/shmem.c:1026 shmem_truncate_range mm/shmem.c:1135 [inline] shmem_evict_inode+0x273/0xa70 mm/shmem.c:1264 evict+0x486/0x870 fs/inode.c:705 __dentry_kill+0x431/0x650 fs/dcache.c:611 dentry_kill+0xb8/0x290 fs/dcache.c:-1 dput+0xfe/0x1e0 fs/dcache.c:918 __fput+0x5e5/0x970 fs/file_table.c:392 task_work_run+0x1ce/0x250 kernel/task_work.c:239 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x90b/0x23c0 kernel/exit.c:883 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024 get_signal+0x12fc/0x1400 kernel/signal.c:2902 arch_do_signal_or_restart+0x9c/0x7b0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xf6/0x180 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: 0033:0x7fe2eb98f749 Code: Unable to access opcode bytes at 0x7fe2eb98f71f. RSP: 002b:00007fe2ec7a8038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: 0000000000010106 RBX: 00007fe2ebbe6180 RCX: 00007fe2eb98f749 RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003 RBP: 00007fe2eba13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe2ebbe6218 R14: 00007fe2ebbe6180 R15: 00007ffee5a2b028