INFO: task syz.5.503:10505 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.503 state:D stack:24160 pid:10505 tgid:10503 ppid:9874 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7289 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244 inode_lock include/linux/fs.h:1028 [inline] generic_file_write_iter+0x11f/0x690 mm/filemap.c:4459 iter_file_splice_write+0x9a6/0x10f0 fs/splice.c:736 do_splice_from fs/splice.c:936 [inline] direct_splice_actor+0x104/0x160 fs/splice.c:1159 splice_direct_to_actor+0x545/0xc80 fs/splice.c:1103 do_splice_direct_actor fs/splice.c:1202 [inline] do_splice_direct+0x19b/0x2a0 fs/splice.c:1228 do_sendfile+0x547/0x7e0 fs/read_write.c:1372[ 584.689345][ T37] do_sendfile+0x547/0x7e0 __do_sys_sendfile64 fs/read_write.c:1433 [inline] __se_sys_sendfile64+0x144/0x1a0 fs/read_write.c:1419 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: 0033:0x7fa52caec799 RSP: 002b:00007fa52ad3e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007fa52cd65fa0 RCX: 00007fa52caec799 RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000004 RBP: 00007fa52cb82c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000020fffe82 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa52cd66038 R14: 00007fa52cd65fa0 R15: 00007fff625f71c8 INFO: task syz.5.503:10530 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.503 state:D stack:26464 pid:10530 tgid:10503 ppid:9874 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0x164/0x360 kernel/sched/core.c:7008 io_schedule+0x80/0xe0 kernel/sched/core.c:7835 TXN_SLEEP_DROP_LOCK fs/jfs/jfs_txnmgr.c:125 [inline] txBeginAnon+0x157/0x410 fs/jfs/jfs_txnmgr.c:469 extAlloc+0x11d/0x1020 fs/jfs/jfs_extent.c:83 jfs_get_block+0x358/0xad0 fs/jfs/inode.c:254 __block_write_begin_int+0x6c6/0x1910 fs/buffer.c:2142 block_write_begin+0x8d/0x120 fs/buffer.c:2253 jfs_write_begin+0x35/0x80 fs/jfs/inode.c:306 generic_perform_write+0x2af/0x8b0 mm/filemap.c:4319 generic_file_write_iter+0x14b/0x690 mm/filemap.c:4462 do_iter_readv_writev+0x62b/0x8d0 fs/read_write.c:-1 vfs_writev+0x345/0x9a0 fs/read_write.c:1059 do_pwritev fs/read_write.c:1155 [inline] __do_sys_pwritev2 fs/read_write.c:1213 [inline] __se_sys_pwritev2+0x187/0x2b0 fs/read_write.c:1204 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: 0033:0x7fa52caec799 RSP: 002b:00007fa52ad1d028 EFLAGS: 00000246 ORIG_RAX: 0000000000000148 RAX: ffffffffffffffda RBX: 00007fa52cd66090 RCX: 00007fa52caec799 RDX: 0000000000000001 RSI: 00002000000001c0 RDI: 0000000000000006 RBP: 00007fa52cb82c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000e7b R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa52cd66128 R14: 00007fa52cd66090 R15: 00007fff625f71c8 Showing all locks held in the system: 4 locks held by pr/legacy/17: 3 locks held by rcuc/0/20: 1 lock held by khungtaskd/37: #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 8 locks held by kworker/u8:4/73: 2 locks held by kworker/u8:13/3077: #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc9000e5dfc40 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc9000e5dfc40 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 2 locks held by getty/5559: #0: ffff888028e5e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e7e2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 2 locks held by syz-executor/5798: 1 lock held by udevd/5845: 4 locks held by udevd/5915: 1 lock held by udevd/5947: #0: ffff8880b8833f90 ((lock)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #0: ffff8880b8833f90 ((lock)#2){+.+.}-{3:3}, at: __folio_batch_add_and_move+0x283/0xa90 mm/swap.c:-1 1 lock held by syz-executor/7549: #0: ffff888057ec20d0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff888057ec20d0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff888057ec20d0 (&type->s_umount_key#71){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 2 locks held by syz.5.503/10505: #0: ffff88802b0be480 (sb_writers#24){.+.+}-{0:0}, at: direct_splice_actor+0x49/0x160 fs/splice.c:1158 #1: ffff888040ab8f78 (&sb->s_type->i_mutex_key#32){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #1: ffff888040ab8f78 (&sb->s_type->i_mutex_key#32){+.+.}-{4:4}, at: generic_file_write_iter+0x11f/0x690 mm/filemap.c:4459 3 locks held by syz.5.503/10530: #0: ffff88802b0be480 (sb_writers#24){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2710 [inline] #0: ffff88802b0be480 (sb_writers#24){.+.+}-{0:0}, at: vfs_writev+0x2b0/0x9a0 fs/read_write.c:1057 #1: ffff888040ab8f78 (&sb->s_type->i_mutex_key#32){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #1: ffff888040ab8f78 (&sb->s_type->i_mutex_key#32){+.+.}-{4:4}, at: generic_file_write_iter+0x11f/0x690 mm/filemap.c:4459 #2: ffff888040ab8b28 (&jfs_ip->rdwrlock#2){++++}-{4:4}, at: jfs_get_block+0x153/0xad0 fs/jfs/inode.c:219 1 lock held by syz.6.520/10740: #0: ffff88803d49e0d0 (&type->s_umount_key#66){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff88803d49e0d0 (&type->s_umount_key#66){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by syz.6.520/10743: #0: ffff88803d49e0d0 (&type->s_umount_key#66){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff88803d49e0d0 (&type->s_umount_key#66){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 6 locks held by syz-executor/10769: #0: ffff88803dd220d0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88803dd220d0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff88803dd220d0 (&type->s_umount_key#71){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffff88805a53b118 (btrfs_trans_num_writers){++++}-{0:0}, at: join_transaction+0x41b/0xc90 fs/btrfs/transaction.c:298 #2: ffff88805a53b140 (btrfs_trans_num_extwriters){++++}-{0:0}, at: join_transaction+0x41b/0xc90 fs/btrfs/transaction.c:298 #3: ffff888035194460 (&delayed_node->mutex){+.+.}-{4:4}, at: btrfs_update_delayed_inode fs/btrfs/delayed-inode.c:1098 [inline] #3: ffff888035194460 (&delayed_node->mutex){+.+.}-{4:4}, at: __btrfs_commit_inode_delayed_items+0x1d72/0x1f60 fs/btrfs/delayed-inode.c:1128 #4: ffff88806ff2e378 (btrfs-tree-01){++++}-{4:4}, at: btrfs_tree_lock_nested+0x33/0x250 fs/btrfs/locking.c:189 #5: ffff8880b8833f90 ((lock)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #5: ffff8880b8833f90 ((lock)#2){+.+.}-{3:3}, at: __folio_batch_add_and_move+0x283/0xa90 mm/swap.c:-1 1 lock held by syz.4.593/11424: #0: ffff88803d49e0d0 (&type->s_umount_key#66){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff88803d49e0d0 (&type->s_umount_key#66){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 3 locks held by syz.0.778/12885: #0: ffff88801aada480 (sb_writers#5){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2710 [inline] #0: ffff88801aada480 (sb_writers#5){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:684 #1: ffff88803f9a2498 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #1: ffff88803f9a2498 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: shmem_file_write_iter+0x82/0x120 mm/shmem.c:3492 #2: ffff8880b8833f90 ((lock)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #2: ffff8880b8833f90 ((lock)#2){+.+.}-{3:3}, at: __folio_batch_add_and_move+0x283/0xa90 mm/swap.c:-1 1 lock held by udevadm/12912: 5 locks held by syz.7.780/12919: #0: ffff8880399c5448 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:310 #1: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #1: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #1: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x200 mm/pgtable-generic.c:288 #2: ffff888029e6fc58 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #2: ffff888029e6fc58 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: pte_offset_map_lock+0x13d/0x210 mm/pgtable-generic.c:402 #3: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #3: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #3: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #3: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57 #4: ffff8880b8833f90 ((lock)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #4: ffff8880b8833f90 ((lock)#2){+.+.}-{3:3}, at: __folio_batch_add_and_move+0x283/0xa90 mm/swap.c:-1 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(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+0xfd9/0x1030 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:436 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: 5845 Comm: udevd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:lookup_chain_cache kernel/locking/lockdep.c:3802 [inline] RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3821 [inline] RIP: 0010:validate_chain kernel/locking/lockdep.c:3876 [inline] RIP: 0010:__lock_acquire+0xc4c/0x2cf0 kernel/locking/lockdep.c:5237 Code: 48 ff cb f7 c1 00 60 00 00 74 c3 e9 90 00 00 00 48 c7 c7 90 8e c9 8d 4c 89 fe e8 df 65 3a 03 48 8b 54 24 18 eb c3 48 8b 48 18 <48> 39 e9 0f 84 b9 00 00 00 48 8b 40 08 48 85 c0 0f 84 ca fe ff ff RSP: 0000:ffffc900046977c8 EFLAGS: 00000097 RAX: ffffffff93614e90 RBX: 0000000000035862 RCX: b7b942e0511c9e73 RDX: 0000000010576b00 RSI: 00000000bc4651f4 RDI: ffff88805fa43d00 RBP: b7b942e0511c9e73 R08: ffffffff8b259edf R09: ffff888044200e58 R10: dffffc0000000000 R11: fffffbfff1ed4957 R12: ffff88805fa44908 R13: ffff88805fa44908 R14: ffff88805fa43d00 R15: 0000000000000002 FS: 00007f8006964880(0000) GS:ffff88812643b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055c84b6a25a8 CR3: 00000000608da000 CR4: 00000000003526f0 Call Trace: lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline] _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:162 rt_mutex_slowunlock+0xbf/0x8b0 kernel/locking/rtmutex.c:1417 spin_unlock include/linux/spinlock_rt.h:109 [inline] wp_page_reuse+0x449/0x830 mm/memory.c:3689 do_wp_page+0x271d/0x49d0 mm/memory.c:4227 handle_pte_fault mm/memory.c:6333 [inline] __handle_mm_fault mm/memory.c:6455 [inline] handle_mm_fault+0x9f5/0x13c0 mm/memory.c:6624 do_user_addr_fault+0xa73/0x1340 arch/x86/mm/fault.c:1334 handle_page_fault arch/x86/mm/fault.c:1474 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7f8006a60b69 Code: 10 48 81 f9 ff 03 00 00 76 28 48 8b 57 20 48 85 d2 74 1f 48 3b 7a 28 75 76 48 8b 4f 28 48 3b 79 20 75 6c 48 83 78 20 00 74 17 <48> 89 4a 28 48 89 51 20 48 83 c4 08 c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fff19fa3080 EFLAGS: 00010202 RAX: 00007f8006b9d280 RBX: 0000000000008040 RCX: 000055c84b6a2580 RDX: 000055c84b6a2580 RSI: 00007f8006b9d280 RDI: 000055c84b6a2580 RBP: 00007f8006b9cac0 R08: 00007f8006b9cac0 R09: 0000000000000000 R10: 0000000000000003 R11: 000000000000000d R12: 0000000000008030 R13: 000055c84b6a2580 R14: 0000000000009ea0 R15: 00007f8006b9cb20