INFO: task syz.5.329:8841 blocked for more than 143 seconds. Not tainted 6.15.0-rc5-syzkaller-00032-g0d8d44db295c #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.329 state:D stack:28952 pid:8841 tgid:8812 ppid:5985 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: 0033:0x7f2b1f98e969 RSP: 002b:00007f2b20826038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f2b1fbb6080 RCX: 00007f2b1f98e969 RDX: 0000200000000080 RSI: 00002000000000c0 RDI: 0000000000000000 RBP: 00007f2b1fa10ab1 R08: 0000200000000400 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f2b1fbb6080 R15: 00007ffe03fa1158 INFO: task syz.5.329:8842 blocked for more than 144 seconds. Not tainted 6.15.0-rc5-syzkaller-00032-g0d8d44db295c #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.329 state:D stack:28952 pid:8842 tgid:8812 ppid:5985 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_sys_chdir fs/open.c:557 [inline] __se_sys_chdir+0x91/0x280 fs/open.c:551 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: 0033:0x7f2b1f98e969 RSP: 002b:00007f2b20805038 EFLAGS: 00000246 ORIG_RAX: 0000000000000050 RAX: ffffffffffffffda RBX: 00007f2b1fbb6160 RCX: 00007f2b1f98e969 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000140 RBP: 00007f2b1fa10ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f2b1fbb6160 R15: 00007ffe03fa1158 Showing all locks held in the system: 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 8 locks held by kworker/u8:2/36: 8 locks held by kworker/u8:3/53: 2 locks held by kworker/u8:8/3019: #0: ffff8880b88399d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:605 #1: ffff8880b8823b08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39e/0x6d0 kernel/sched/psi.c:987 2 locks held by getty/5572: #0: ffff8880336da0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036d32f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 5 locks held by syz.5.329/8813: #0: ffff88804e1a6420 (sb_writers#20){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556 #1: ffff8880777cb670 (&sb->s_type->i_mutex_key#25/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:902 [inline] #1: ffff8880777cb670 (&sb->s_type->i_mutex_key#25/1){+.+.}-{4:4}, at: filename_create+0x1f9/0x470 fs/namei.c:4132 #2: ffff8880777cba58 (&inode->ei_update_lock){+.+.}-{4:4}, at: __bch2_create+0x2f2/0xb90 fs/bcachefs/fs.c:569 #3: ffff88806c004228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline] #3: ffff88806c004228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline] #3: ffff88806c004228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: bch2_trans_srcu_lock+0xaf/0x220 fs/bcachefs/btree_iter.c:3202 #4: ffff88806c026590 (&c->gc_lock){++++}-{4:4}, at: bch2_btree_update_start+0x68f/0x14c0 fs/bcachefs/btree_update_interior.c:1179 1 lock held by syz.5.329/8841: #0: ffff8880777cb670 (&sb->s_type->i_mutex_key#25){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:877 [inline] #0: ffff8880777cb670 (&sb->s_type->i_mutex_key#25){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1833 1 lock held by syz.5.329/8842: #0: ffff8880777cb670 (&sb->s_type->i_mutex_key#25){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:877 [inline] #0: ffff8880777cb670 (&sb->s_type->i_mutex_key#25){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1833 3 locks held by bch-copygc/loop/8834: 2 locks held by syz-executor/9112: #0: ffff8880664d40e0 (&type->s_umount_key#79){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff8880664d40e0 (&type->s_umount_key#79){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff8880664d40e0 (&type->s_umount_key#79){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505 #1: ffffffff8df41200 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3774 2 locks held by syz-executor/10170: #0: ffff88805984e0e0 (&type->s_umount_key#79){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff88805984e0e0 (&type->s_umount_key#79){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88805984e0e0 (&type->s_umount_key#79){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505 #1: ffffffff8df41200 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3774 1 lock held by syz.6.569/11343: #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.6.569/11400: 2 locks held by dhcpcd-run-hook/11410: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc5-syzkaller-00032-g0d8d44db295c #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 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: 11400 Comm: syz.6.569 Not tainted 6.15.0-rc5-syzkaller-00032-g0d8d44db295c #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210 Code: 89 fb e8 23 00 00 00 48 8b 3d ec d4 d5 0b 48 89 de 5b e9 f3 3c 55 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 08 30 72 92 65 8b 15 b8 60 RSP: 0018:ffffc9000af77970 EFLAGS: 00000206 RAX: 1ffff920015eefb4 RBX: dffffc0000000000 RCX: 0000000000000001 RDX: ffffffff84afae2f RSI: ffffffff8e6a2720 RDI: 0000000000000000 RBP: ffffc9000af77b30 R08: ffff88801eb21e00 R09: 0000000000000006 R10: 0000000000000005 R11: 0000000000000002 R12: 1ffff920015eefb3 R13: 0000000000000000 R14: ffffc9000af77d98 R15: 00007f3d7ab29000 FS: 00007f3d853606c0(0000) GS:ffff8881261fd000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2d36a41ba8 CR3: 000000005fb06000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: should_fail_usercopy+0x9/0x20 lib/fault-inject-usercopy.c:36 copy_from_user_iter lib/iov_iter.c:50 [inline] iterate_ubuf include/linux/iov_iter.h:30 [inline] iterate_and_advance2 include/linux/iov_iter.h:300 [inline] iterate_and_advance include/linux/iov_iter.h:328 [inline] __copy_from_iter lib/iov_iter.c:249 [inline] copy_page_from_iter_atomic+0x2bc/0x18a0 lib/iov_iter.c:483 copy_folio_from_iter_atomic include/linux/uio.h:210 [inline] generic_perform_write+0x5f1/0x910 mm/filemap.c:4121 shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3464 new_sync_write fs/read_write.c:591 [inline] vfs_write+0x548/0xa90 fs/read_write.c:684 ksys_write+0x145/0x250 fs/read_write.c:736 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: 0033:0x7f3d8458d41f Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48 RSP: 002b:00007f3d8535fdf0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007f3d8458d41f RDX: 0000000001000000 RSI: 00007f3d79e00000 RDI: 0000000000000006 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000005a96 R10: 000020000000c102 R11: 0000000000000293 R12: 0000000000000006 R13: 00007f3d8535fef0 R14: 00007f3d8535feb0 R15: 00007f3d79e00000