INFO: task syz.3.98:6772 blocked for more than 143 seconds. Not tainted 6.15.0-rc6-syzkaller-00278-g172a9d94339c #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.98 state:D stack:26744 pid:6772 tgid:6733 ppid:5819 task_flags:0x400140 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_nested+0x1b5/0x200 kernel/locking/rwsem.c:1694 inode_lock_nested include/linux/fs.h:902 [inline] filename_create+0x1f9/0x470 fs/namei.c:4132 do_mknodat+0x184/0x4d0 fs/namei.c:4265 __do_sys_mknod fs/namei.c:4311 [inline] __se_sys_mknod fs/namei.c:4309 [inline] __x64_sys_mknod+0x8c/0xa0 fs/namei.c:4309 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: 0033:0x7f5c92b8e969 RSP: 002b:00007f5c93997038 EFLAGS: 00000246 ORIG_RAX: 0000000000000085 RAX: ffffffffffffffda RBX: 00007f5c92db6080 RCX: 00007f5c92b8e969 RDX: 0000000000000707 RSI: 0000000000000000 RDI: 0000200000000000 RBP: 00007f5c92c10ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f5c92db6080 R15: 00007ffd653ff108 INFO: task syz.3.98:6773 blocked for more than 144 seconds. Not tainted 6.15.0-rc6-syzkaller-00278-g172a9d94339c #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.98 state:D stack:28200 pid:6773 tgid:6733 ppid:5819 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: 0033:0x7f5c92b8e969 RSP: 002b:00007f5c93976038 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 RAX: ffffffffffffffda RBX: 00007f5c92db6160 RCX: 00007f5c92b8e969 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000d80 RBP: 00007f5c92c10ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f5c92db6160 R15: 00007ffd653ff108 INFO: task syz.3.98:6774 blocked for more than 145 seconds. Not tainted 6.15.0-rc6-syzkaller-00278-g172a9d94339c #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.98 state:D stack:28952 pid:6774 tgid:6733 ppid:5819 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_nested+0x1b5/0x200 kernel/locking/rwsem.c:1694 inode_lock_nested include/linux/fs.h:902 [inline] lock_rename fs/namei.c:3265 [inline] do_renameat2+0x3dd/0xc50 fs/namei.c:5216 __do_sys_rename fs/namei.c:5317 [inline] __se_sys_rename fs/namei.c:5315 [inline] __x64_sys_rename+0x82/0x90 fs/namei.c:5315 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: 0033:0x7f5c92b8e969 RSP: 002b:00007f5c93955038 EFLAGS: 00000246 ORIG_RAX: 0000000000000052 RAX: ffffffffffffffda RBX: 00007f5c92db6240 RCX: 00007f5c92b8e969 RDX: 0000000000000000 RSI: 0000200000000180 RDI: 00002000000003c0 RBP: 00007f5c92c10ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f5c92db6240 R15: 00007ffd653ff108 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8df3dce0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df3dce0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8df3dce0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764 4 locks held by kworker/u8:2/36: #0: ffff888141286148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff888141286148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc90000ad7c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000ad7c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 #2: ffff8880227020e0 (&type->s_umount_key#75){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:562 #3: ffff88805ac73918 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:102 2 locks held by getty/5581: #0: ffff888034e820a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002fee2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 2 locks held by kworker/0:3/5811: 4 locks held by syz.3.98/6734: 2 locks held by syz.3.98/6772: #0: ffff888022702420 (sb_writers#20){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556 #1: ffff88805ac73cc8 (&type->i_mutex_dir_key#14/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:902 [inline] #1: ffff88805ac73cc8 (&type->i_mutex_dir_key#14/1){+.+.}-{4:4}, at: filename_create+0x1f9/0x470 fs/namei.c:4132 2 locks held by syz.3.98/6773: #0: ffff888022702420 (sb_writers#20){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556 #1: ffff88805ac73cc8 (&type->i_mutex_dir_key#18){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] #1: ffff88805ac73cc8 (&type->i_mutex_dir_key#18){++++}-{4:4}, at: open_last_lookups fs/namei.c:3797 [inline] #1: ffff88805ac73cc8 (&type->i_mutex_dir_key#18){++++}-{4:4}, at: path_openat+0x8da/0x3830 fs/namei.c:4036 2 locks held by syz.3.98/6774: #0: ffff888022702420 (sb_writers#20){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556 #1: ffff88805ac73cc8 (&type->i_mutex_dir_key#14/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:902 [inline] #1: ffff88805ac73cc8 (&type->i_mutex_dir_key#14/1){+.+.}-{4:4}, at: lock_rename fs/namei.c:3265 [inline] #1: ffff88805ac73cc8 (&type->i_mutex_dir_key#14/1){+.+.}-{4:4}, at: do_renameat2+0x3dd/0xc50 fs/namei.c:5216 1 lock held by syz-executor/6990: #0: ffffffff8df437b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #0: ffffffff8df437b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b7/0x730 kernel/rcu/tree_exp.h:998 1 lock held by syz-executor/7904: #0: ffffffff8df437b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline] #0: ffffffff8df437b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f4/0x730 kernel/rcu/tree_exp.h:998 2 locks held by syz-executor/8749: #0: ffffffff8e66ffc8 (bio_slab_lock){+.+.}-{4:4}, at: bio_put_slab block/bio.c:140 [inline] #0: ffffffff8e66ffc8 (bio_slab_lock){+.+.}-{4:4}, at: bioset_exit+0x44a/0x690 block/bio.c:1664 #1: ffffffff8df43680 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3774 1 lock held by syz.0.353/9272: #0: ffffffff8e66ffc8 (bio_slab_lock){+.+.}-{4:4}, at: bio_find_or_create_slab block/bio.c:122 [inline] #0: ffffffff8e66ffc8 (bio_slab_lock){+.+.}-{4:4}, at: bioset_init+0x241/0x790 block/bio.c:1705 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc6-syzkaller-00278-g172a9d94339c #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 9272 Comm: syz.0.353 Not tainted 6.15.0-rc6-syzkaller-00278-g172a9d94339c #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:rdtsc_ordered arch/x86/include/asm/msr.h:217 [inline] RIP: 0010:delay_tsc+0x21/0xc0 arch/x86/lib/delay.c:70 Code: 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 53 48 89 fb bf 01 00 00 00 e8 d9 96 42 f6 e8 34 39 01 00 89 c5 0f 01 f9 <66> 90 49 89 d6 49 c1 e6 20 49 09 c6 0f 01 f9 66 90 49 89 d7 49 c1 RSP: 0018:ffffc90004df68d0 EFLAGS: 00000082 RAX: 00000000124d18e0 RBX: 0000000000000899 RCX: 0000000000000001 RDX: 00000000000000a2 RSI: ffffffff8bc11fe0 RDI: ffffffff8bc11fa0 RBP: 0000000000000001 R08: ffff8880240f0237 R09: 1ffff1100481e046 R10: dffffc0000000000 R11: ffffffff8b4e5840 R12: 1ffffffff3364392 R13: 00000000ffffffff R14: dffffc0000000000 R15: 00000000000007e0 FS: 00007fd2b9f4e6c0(0000) GS:ffff8881261f6000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7d4d9757b8 CR3: 0000000011620000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: udelay include/asm-generic/delay.h:62 [inline] wait_for_lsr+0x160/0x2f0 drivers/tty/serial/8250/8250_port.c:2104 fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3348 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3371 [inline] serial8250_console_write+0x134c/0x1ba0 drivers/tty/serial/8250/8250_port.c:3456 console_emit_next_record kernel/printk/printk.c:3138 [inline] console_flush_all+0x725/0xc40 kernel/printk/printk.c:3226 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline] console_unlock+0xc4/0x270 kernel/printk/printk.c:3325 vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450 _printk+0xcf/0x120 kernel/printk/printk.c:2475 show_free_areas mm/show_mem.c:203 [inline] __show_mem+0x903/0x2210 mm/show_mem.c:407 warn_alloc_show_mem mm/page_alloc.c:3738 [inline] warn_alloc+0x2dd/0x310 mm/page_alloc.c:3763 __vmalloc_area_node mm/vmalloc.c:3652 [inline] __vmalloc_node_range_noprof+0x5f2/0x12c0 mm/vmalloc.c:3845 __kvmalloc_node_noprof+0x3a0/0x5e0 mm/slub.c:5034 bch2_fs_journal_init+0x2af/0x7e0 fs/bcachefs/journal.c:1613 bch2_fs_alloc fs/bcachefs/super.c:912 [inline] bch2_fs_open+0x21b9/0x2820 fs/bcachefs/super.c:2210 bch2_fs_get_tree+0x45d/0x13b0 fs/bcachefs/fs.c:2491 vfs_get_tree+0x92/0x2b0 fs/super.c:1759 do_new_mount+0x24a/0xa40 fs/namespace.c:3881 do_mount fs/namespace.c:4221 [inline] __do_sys_mount fs/namespace.c:4432 [inline] __se_sys_mount+0x317/0x410 fs/namespace.c:4409 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: 0033:0x7fd2b919010a Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fd2b9f4de68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fd2b9f4def0 RCX: 00007fd2b919010a RDX: 0000200000000440 RSI: 0000200000000080 RDI: 00007fd2b9f4deb0 RBP: 0000200000000440 R08: 00007fd2b9f4def0 R09: 0000000002800000 R10: 0000000002800000 R11: 0000000000000246 R12: 0000200000000080 R13: 00007fd2b9f4deb0 R14: 0000000000005a7e R15: 0000200000000a00