INFO: task syz.0.18:6758 blocked for more than 143 seconds. Not tainted 6.13.0-rc1-syzkaller-00017-gaaec5a95d596-dirty #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.18 state:D stack:26608 pid:6758 tgid:6757 ppid:6540 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0xe58/0x5ad0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6848 bit_wait+0x15/0xe0 kernel/sched/wait_bit.c:237 __wait_on_bit+0x62/0x180 kernel/sched/wait_bit.c:49 out_of_line_wait_on_bit+0xda/0x110 kernel/sched/wait_bit.c:64 wait_on_bit include/linux/wait_bit.h:77 [inline] netfs_unbuffered_write_iter_locked+0xba8/0xe70 fs/netfs/direct_write.c:105 netfs_unbuffered_write_iter+0x413/0x6d0 fs/netfs/direct_write.c:193 v9fs_file_write_iter+0xbf/0x100 fs/9p/vfs_file.c:404 new_sync_write fs/read_write.c:586 [inline] vfs_write+0x5ae/0x1150 fs/read_write.c:679 ksys_write+0x12b/0x250 fs/read_write.c:731 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fae42f8d169 RSP: 002b:00007fae43eb2038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fae431a5fa0 RCX: 00007fae42f8d169 RDX: 0000000000007fec RSI: 0000400000000540 RDI: 0000000000000007 RBP: 00007fae4300e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fae431a5fa0 R15: 00007ffef04451c8 Showing all locks held in the system: 2 locks held by kworker/u8:1/12: #0: ffff88801b081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3204 #1: ffffc90000117d80 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 1 lock held by khungtaskd/30: #0: ffffffff8e1bac80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e1bac80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e1bac80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6744 2 locks held by kworker/u8:3/52: #0: ffff88801b081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3204 #1: ffffc90000bd7d80 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 2 locks held by kworker/u8:4/63: #0: ffff88801b081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3204 #1: ffffc9000214fd80 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 2 locks held by kworker/u8:5/1034: #0: ffff88801b081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3204 #1: ffffc9000403fd80 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 2 locks held by kworker/u8:6/2116: #0: ffff88801b081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3204 #1: ffffc90005937d80 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 2 locks held by kworker/u8:7/4367: #0: ffff88801b081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3204 #1: ffffc9000f717d80 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 2 locks held by kworker/u8:8/4487: #0: ffff88801b081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3204 #1: ffffc9000fd07d80 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 2 locks held by kworker/u8:9/4559: #0: ffff88801b081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3204 #1: ffffc9000ffe7d80 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 2 locks held by getty/5582: #0: ffff8880313180a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc90002fde2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211 3 locks held by syz.0.18/6758: #0: ffff888026eba478 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x267/0x390 fs/file.c:1191 #1: ffff888024f5a420 (sb_writers#14){.+.+}-{0:0}, at: ksys_write+0x12b/0x250 fs/read_write.c:731 #2: ffff8880755987b8 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: netfs_start_io_direct+0x116/0x260 fs/netfs/locking.c:188 3 locks held by syz.1.23/6787: #0: ffff88803111c9b8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x267/0x390 fs/file.c:1191 #1: ffff88807d6da420 (sb_writers#14){.+.+}-{0:0}, at: ksys_write+0x12b/0x250 fs/read_write.c:731 #2: ffff888075720148 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: netfs_start_io_direct+0x116/0x260 fs/netfs/locking.c:188 3 locks held by syz.2.25/6807: #0: ffff88803562d438 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x267/0x390 fs/file.c:1191 #1: ffff888027a9e420 (sb_writers#14){.+.+}-{0:0}, at: ksys_write+0x12b/0x250 fs/read_write.c:731 #2: ffff88807559a178 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: netfs_start_io_direct+0x116/0x260 fs/netfs/locking.c:188 3 locks held by syz.3.28/6829: #0: ffff888026d3e9b8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x267/0x390 fs/file.c:1191 #1: ffff888025ffa420 (sb_writers#14){.+.+}-{0:0}, at: ksys_write+0x12b/0x250 fs/read_write.c:731 #2: ffff8880757207b8 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: netfs_start_io_direct+0x116/0x260 fs/netfs/locking.c:188 3 locks held by syz.4.30/6854: #0: ffff888033e600f8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x267/0x390 fs/file.c:1191 #1: ffff888036adc420 (sb_writers#14){.+.+}-{0:0}, at: ksys_write+0x12b/0x250 fs/read_write.c:731 #2: ffff888075720e28 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: netfs_start_io_direct+0x116/0x260 fs/netfs/locking.c:188 2 locks held by kworker/u8:10/6856: #0: ffff88801b081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3204 #1: ffffc90002ee7d80 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 3 locks held by syz.5.32/6881: #0: ffff88803162deb8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x267/0x390 fs/file.c:1191 #1: ffff88802aa02420 (sb_writers#14){.+.+}-{0:0}, at: ksys_write+0x12b/0x250 fs/read_write.c:731 #2: ffff88807559a7e8 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: netfs_start_io_direct+0x116/0x260 fs/netfs/locking.c:188 3 locks held by kworker/u8:11/6882: 3 locks held by syz.6.34/6908: #0: ffff88804f312d38 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x267/0x390 fs/file.c:1191 #1: ffff888062c8c420 (sb_writers#14){.+.+}-{0:0}, at: ksys_write+0x12b/0x250 fs/read_write.c:731 #2: ffff888075721498 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: netfs_start_io_direct+0x116/0x260 fs/netfs/locking.c:188 2 locks held by kworker/u8:12/6909: #0: ffff88801b081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3204 #1: ffffc900021dfd80 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 3 locks held by syz.7.36/6935: #0: ffff8880369530b8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x267/0x390 fs/file.c:1191 #1: ffff888063c48420 (sb_writers#14){.+.+}-{0:0}, at: ksys_write+0x12b/0x250 fs/read_write.c:731 #2: ffff888075721b08 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: netfs_start_io_direct+0x116/0x260 fs/netfs/locking.c:188 3 locks held by syz.8.38/6968: #0: ffff88801e2adeb8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x267/0x390 fs/file.c:1191 #1: ffff88807b25e420 (sb_writers#14){.+.+}-{0:0}, at: ksys_write+0x12b/0x250 fs/read_write.c:731 #2: ffff88807559ae58 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: netfs_start_io_direct+0x116/0x260 fs/netfs/locking.c:188 3 locks held by syz.9.40/6997: #0: ffff88802a74a7f8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x267/0x390 fs/file.c:1191 #1: ffff888053afa420 (sb_writers#14){.+.+}-{0:0}, at: ksys_write+0x12b/0x250 fs/read_write.c:731 #2: ffff888075722178 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: netfs_start_io_direct+0x116/0x260 fs/netfs/locking.c:188 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.13.0-rc1-syzkaller-00017-gaaec5a95d596-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:234 [inline] watchdog+0xf14/0x1240 kernel/hung_task.c:397 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5182 Comm: klogd Not tainted 6.13.0-rc1-syzkaller-00017-gaaec5a95d596-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:__raw_callee_save___pv_queued_spin_unlock+0x12/0x18 Code: 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 52 b8 01 00 00 00 31 d2 f0 0f b0 17 75 06 <5a> c3 cc cc cc cc 56 0f b6 f0 e8 9f ff ff ff 5e 5a c3 cc cc cc cc RSP: 0018:ffffc90005667618 EFLAGS: 00000046 RAX: 0000000000000001 RBX: ffffffff9a9f6bc8 RCX: ffffffff81770803 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff9a9f6bc8 RBP: ffffffff9a9f6bd0 R08: 0000000000000000 R09: fffffbfff353ed79 R10: ffffffff9a9f6bcb R11: 0000000000000001 R12: ffffffff9a9f6bd8 R13: 0000000000000012 R14: 0000000000000000 R15: ffff888067f30000 FS: 00007fb083fb7500(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005612bebd5240 CR3: 00000000347be000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: pv_queued_spin_unlock arch/x86/include/asm/paravirt.h:589 [inline] queued_spin_unlock arch/x86/include/asm/qspinlock.h:57 [inline] do_raw_spin_unlock+0x172/0x230 kernel/locking/spinlock_debug.c:142 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:150 [inline] _raw_spin_unlock_irqrestore+0x22/0x80 kernel/locking/spinlock.c:194 __debug_check_no_obj_freed lib/debugobjects.c:1108 [inline] debug_check_no_obj_freed+0x327/0x600 lib/debugobjects.c:1129 free_pages_prepare mm/page_alloc.c:1134 [inline] free_unref_page+0x276/0x1080 mm/page_alloc.c:2657 __put_partials+0x14c/0x170 mm/slub.c:3142 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4e/0x120 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4104 [inline] slab_alloc_node mm/slub.c:4153 [inline] kmem_cache_alloc_node_noprof+0x223/0x3c0 mm/slub.c:4205 __alloc_skb+0x2b1/0x380 net/core/skbuff.c:668 alloc_skb include/linux/skbuff.h:1323 [inline] alloc_skb_with_frags+0xe4/0x850 net/core/skbuff.c:6612 sock_alloc_send_pskb+0x7f1/0x980 net/core/sock.c:2881 unix_dgram_sendmsg+0x4b8/0x19e0 net/unix/af_unix.c:2027 sock_sendmsg_nosec net/socket.c:711 [inline] __sock_sendmsg net/socket.c:726 [inline] __sys_sendto+0x488/0x4f0 net/socket.c:2197 __do_sys_sendto net/socket.c:2204 [inline] __se_sys_sendto net/socket.c:2200 [inline] __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2200 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb0841199b5 Code: 8b 44 24 08 48 83 c4 28 48 98 c3 48 98 c3 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 26 45 31 c9 45 31 c0 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 7a 48 8b 15 44 c4 0c 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffd368d15b8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fb0841199b5 RDX: 0000000000000049 RSI: 0000558a1e31e270 RDI: 0000000000000003 RBP: 0000558a1e3172c0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000004000 R11: 0000000000000246 R12: 0000000000000013 R13: 00007fb0842a7212 R14: 00007ffd368d16b8 R15: 0000000000000000