INFO: task syz-executor286:5846 blocked for more than 143 seconds. Not tainted 6.15.0-rc5-syzkaller-00136-g9c69f8884904 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor286 state:D stack:19624 pid:5846 tgid:5846 ppid:5844 task_flags:0x400140 flags:0x00004006 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 __closure_sync+0x163/0x220 lib/closure.c:146 bch2_wait_on_allocator fs/bcachefs/alloc_foreground.h:256 [inline] bch2_btree_update_start+0x1193/0x14c0 fs/bcachefs/btree_update_interior.c:1251 bch2_btree_split_leaf+0x13c/0x8f0 fs/bcachefs/btree_update_interior.c:1879 bch2_trans_commit_error+0x1a8/0x1100 fs/bcachefs/btree_trans_commit.c:904 __bch2_trans_commit+0x779c/0x8ae0 fs/bcachefs/btree_trans_commit.c:1069 bch2_trans_commit fs/bcachefs/btree_update.h:195 [inline] __bch2_create+0x887/0xb90 fs/bcachefs/fs.c:595 bch2_mknod+0x67/0xd0 fs/bcachefs/fs.c:752 vfs_mknod+0x37c/0x3c0 fs/namei.c:4228 do_mknodat+0x385/0x4d0 fs/namei.c:-1 __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: 0033:0x7f870a6aed59 RSP: 002b:00007ffec8ab8338 EFLAGS: 00000246 ORIG_RAX: 0000000000000085 RAX: ffffffffffffffda RBX: 0000200000000080 RCX: 00007f870a6aed59 RDX: 0000000000000000 RSI: 0000000000001000 RDI: 0000200000000080 RBP: 00007f870a7325f0 R08: 000000000000f624 R09: 00005555791aa4c0 R10: 00007ffec8ab8200 R11: 0000000000000246 R12: 00007ffec8ab8360 R13: 00007ffec8ab8588 R14: 431bde82d7b634db R15: 00007f870a6f803b 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 2 locks held by getty/5580: #0: ffff888034caa0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000333b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 5 locks held by syz-executor286/5846: #0: ffff88807dfa4420 (sb_writers#8){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556 #1: ffff888077ae0148 (&sb->s_type->i_mutex_key#14/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:902 [inline] #1: ffff888077ae0148 (&sb->s_type->i_mutex_key#14/1){+.+.}-{4:4}, at: filename_create+0x1f9/0x470 fs/namei.c:4132 #2: ffff888077ae0530 (&inode->ei_update_lock){+.+.}-{4:4}, at: __bch2_create+0x2f2/0xb90 fs/bcachefs/fs.c:569 #3: ffff888078184228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline] #3: ffff888078184228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline] #3: ffff888078184228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: __bch2_trans_get+0x806/0xda0 fs/bcachefs/btree_iter.c:3385 #4: ffff8880781a6590 (&c->gc_lock){.+.+}-{4:4}, at: bch2_btree_update_start+0x68f/0x14c0 fs/bcachefs/btree_update_interior.c:1179 2 locks held by bch-copygc/loop/5855: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc5-syzkaller-00136-g9c69f8884904 #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: 5855 Comm: bch-copygc/loop Not tainted 6.15.0-rc5-syzkaller-00136-g9c69f8884904 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 RIP: 0010:lock_acquire+0xb/0x360 kernel/locking/lockdep.c:5826 Code: 95 c0 c3 cc cc cc cc cc 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 41 55 <41> 54 53 48 83 ec 60 4d 89 ce 45 89 c7 41 89 cc 89 54 24 04 89 f3 RSP: 0018:ffffc9000415ef08 EFLAGS: 00000246 RAX: 0000000000000001 RBX: ffffffff8171d298 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8df3b860 RBP: dffffc0000000000 R08: 0000000000000000 R09: 0000000000000000 R10: ffffc9000415f068 R11: fffff5200082be19 R12: 1ffff9200082be0d R13: ffffc9000415f0a0 R14: ffffc9000415f068 R15: ffffffff8171a9f5 FS: 0000000000000000(0000) GS:ffff888126200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffde2a2af19 CR3: 000000000dd36000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479 __unwind_start+0x5b9/0x760 arch/x86/kernel/unwind_orc.c:758 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe4/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2380 [inline] slab_free mm/slub.c:4642 [inline] kfree+0x193/0x440 mm/slub.c:4841 move_buckets_wait+0x1024/0x12d0 fs/bcachefs/movinggc.c:134 bch2_copygc_get_buckets fs/bcachefs/movinggc.c:158 [inline] bch2_copygc+0x281/0x3cf0 fs/bcachefs/movinggc.c:221 bch2_copygc_thread+0x8c9/0xd40 fs/bcachefs/movinggc.c:405 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 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.364 msecs