INFO: task syz.1.150:7372 blocked for more than 143 seconds. Not tainted 6.15.0-rc4-syzkaller-00189-g2bfcee565c3a #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.150 state:D stack:28776 pid:7372 tgid:7305 ppid:6575 task_flags:0x400040 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x168f/0x4c70 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x165/0x360 kernel/sched/core.c:6860 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917 rwsem_down_write_slowpath+0xbec/0x1030 kernel/locking/rwsem.c:1176 __down_write_common kernel/locking/rwsem.c:1304 [inline] __down_write kernel/locking/rwsem.c:1313 [inline] down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1578 inode_lock include/linux/fs.h:867 [inline] open_last_lookups fs/namei.c:3797 [inline] path_openat+0x8da/0x3830 fs/namei.c:4036 do_filp_open+0x1fa/0x410 fs/namei.c:4066 do_sys_openat2+0x121/0x1c0 fs/open.c:1429 do_sys_open fs/open.c:1444 [inline] __do_sys_creat fs/open.c:1522 [inline] __se_sys_creat fs/open.c:1516 [inline] __x64_sys_creat+0x8f/0xc0 fs/open.c:1516 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f039f38e969 RSP: 002b:00007f03a026f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 RAX: ffffffffffffffda RBX: 00007f039f5b6080 RCX: 00007f039f38e969 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000100 RBP: 00007f039f410ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f039f5b6080 R15: 00007ffdf3b5d398 INFO: task syz.1.150:7374 blocked for more than 144 seconds. Not tainted 6.15.0-rc4-syzkaller-00189-g2bfcee565c3a #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.150 state:D stack:28952 pid:7374 tgid:7305 ppid:6575 task_flags:0x400040 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x168f/0x4c70 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x165/0x360 kernel/sched/core.c:6860 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917 rwsem_down_read_slowpath+0x552/0x880 kernel/locking/rwsem.c:1084 __down_read_common kernel/locking/rwsem.c:1248 [inline] __down_read kernel/locking/rwsem.c:1261 [inline] down_read+0x98/0x2e0 kernel/locking/rwsem.c:1526 inode_lock_shared include/linux/fs.h:877 [inline] lookup_slow+0x46/0x70 fs/namei.c:1833 walk_component+0x2d2/0x400 fs/namei.c:2138 lookup_last fs/namei.c:2636 [inline] path_lookupat+0x163/0x430 fs/namei.c:2660 filename_lookup+0x212/0x570 fs/namei.c:2689 user_path_at+0x3a/0x60 fs/namei.c:3120 do_mount fs/namespace.c:4221 [inline] __do_sys_mount fs/namespace.c:4435 [inline] __se_sys_mount+0x2d3/0x410 fs/namespace.c:4412 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f039f38e969 RSP: 002b:00007f03a024e038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f039f5b6160 RCX: 00007f039f38e969 RDX: 0000200000000140 RSI: 0000200000000080 RDI: 0000200000000040 RBP: 00007f039f410ab1 R08: 0000200000000180 R09: 0000000000000000 R10: 0000000000200000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f039f5b6160 R15: 00007ffdf3b5d398 Showing all locks held in the system: 2 locks held by kworker/u8:1/13: 1 lock held by khungtaskd/31: #0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764 4 locks held by kworker/u8:6/1160: #0: ffff88801fac8948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801fac8948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc90003e3fc60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90003e3fc60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 #2: ffff88805b0480e0 (&type->s_umount_key#74){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:562 #3: ffff88807afa0cc8 (&inode->ei_update_lock#3){+.+.}-{4:4}, at: bch2_vfs_write_inode+0x6a/0xd0 fs/bcachefs/fs.c:2171 2 locks held by getty/5577: #0: ffff888030c640a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002ffe2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 5 locks held by syz.1.150/7307: #0: ffff88805b048420 (sb_writers#27){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556 #1: ffff88807afa08e0 (&sb->s_type->i_mutex_key#31){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] #1: ffff88807afa08e0 (&sb->s_type->i_mutex_key#31){++++}-{4:4}, at: open_last_lookups fs/namei.c:3797 [inline] #1: ffff88807afa08e0 (&sb->s_type->i_mutex_key#31){++++}-{4:4}, at: path_openat+0x8da/0x3830 fs/namei.c:4036 #2: ffff88807afa0cc8 (&inode->ei_update_lock#3){+.+.}-{4:4}, at: __bch2_create+0x2f2/0xb90 fs/bcachefs/fs.c:569 #3: ffff88806ce04228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline] #3: ffff88806ce04228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline] #3: ffff88806ce04228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: __bch2_trans_get+0x806/0xda0 fs/bcachefs/btree_iter.c:3385 #4: ffff88806ce26590 (&c->gc_lock){++++}-{4:4}, at: bch2_btree_update_start+0x68f/0x14c0 fs/bcachefs/btree_update_interior.c:1179 2 locks held by syz.1.150/7372: #0: ffff88805b048420 (sb_writers#27){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556 #1: ffff88807afa08e0 (&sb->s_type->i_mutex_key#31){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] #1: ffff88807afa08e0 (&sb->s_type->i_mutex_key#31){++++}-{4:4}, at: open_last_lookups fs/namei.c:3797 [inline] #1: ffff88807afa08e0 (&sb->s_type->i_mutex_key#31){++++}-{4:4}, at: path_openat+0x8da/0x3830 fs/namei.c:4036 1 lock held by syz.1.150/7374: #0: ffff88807afa08e0 (&sb->s_type->i_mutex_key#31){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:877 [inline] #0: ffff88807afa08e0 (&sb->s_type->i_mutex_key#31){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1833 2 locks held by bch-copygc/loop/7361: 2 locks held by syz.0.198/7827: #0: ffff88805b0480e0 (&type->s_umount_key#74){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88805b0480e0 (&type->s_umount_key#74){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120 #1: ffff88805b03e7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff88805b03e7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831 1 lock held by syz-executor/8047: #0: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #0: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b7/0x730 kernel/rcu/tree_exp.h:998 2 locks held by syz.5.299/9116: #0: ffff88805b0480e0 (&type->s_umount_key#74){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88805b0480e0 (&type->s_umount_key#74){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120 #1: ffff88805b03e7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff88805b03e7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831 2 locks held by syz.3.319/9689: #0: ffff88805b0480e0 (&type->s_umount_key#74){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88805b0480e0 (&type->s_umount_key#74){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120 #1: ffff88805b03e7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff88805b03e7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831 1 lock held by rm/9872: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc4-syzkaller-00189-g2bfcee565c3a #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 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:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:437 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 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: 5187 Comm: udevd Not tainted 6.15.0-rc4-syzkaller-00189-g2bfcee565c3a #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 RIP: 0010:jhash2 include/linux/jhash.h:135 [inline] RIP: 0010:hash_stack lib/stackdepot.c:514 [inline] RIP: 0010:stack_depot_save_flags+0xe9/0x910 lib/stackdepot.c:615 Code: c9 41 29 c1 89 c5 c1 c5 04 44 31 cd 01 c8 83 c6 fd 48 83 c2 0c 83 fe 03 77 9a eb 07 4c 89 f2 89 e9 89 e8 83 fe 01 89 5c 24 0c <7f> 0a 85 f6 8b 74 24 08 75 11 eb 4c 83 fe 02 8b 74 24 08 74 03 03 RSP: 0018:ffffc90002f67aa0 EFLAGS: 00000246 RAX: 00000000d521f6e9 RBX: 0000000000002800 RCX: 00000000f9ca4406 RDX: ffffc90002f67b4c RSI: 0000000000000001 RDI: 00000000a9d8f222 RBP: 00000000ed7149f4 R08: 00000000918181a2 R09: 00000000580a67c9 R10: 0000000000000008 R11: ffffffff81ce8396 R12: 0000000000000001 R13: ffff88803411d280 R14: ffffc90002f67b10 R15: ffffc90002f67b10 FS: 00007fe7a4c9ac80(0000) GS:ffff888126100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffe9ecaa0d8 CR3: 0000000031b94000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: kasan_save_stack mm/kasan/common.c:48 [inline] kasan_save_track+0x4f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4358 kmalloc_noprof include/linux/slab.h:905 [inline] slab_free_hook mm/slub.c:2332 [inline] slab_free mm/slub.c:4642 [inline] kmem_cache_free+0x169/0x3f0 mm/slub.c:4744 fput_close_sync+0x119/0x200 fs/file_table.c:570 __do_sys_close fs/open.c:1581 [inline] __se_sys_close fs/open.c:1566 [inline] __x64_sys_close+0x7f/0x110 fs/open.c:1566 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe7a49170a8 Code: 48 8b 05 83 9d 0d 00 64 c7 00 16 00 00 00 83 c8 ff 48 83 c4 20 5b c3 64 8b 04 25 18 00 00 00 85 c0 75 20 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 5b 48 8b 15 51 9d 0d 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffedb5c5098 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 00007fe7a4c9aae0 RCX: 00007fe7a49170a8 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000000000c RBP: 000000000000000c R08: 00000000ffffffff R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002 R13: ffffffffffffffff R14: 00000000ffffffff R15: 00000000ffffffff