INFO: task syz-executor:5766 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21608 pid:5766 ppid:1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 bit_wait+0x11/0xd0 kernel/sched/wait_bit.c:199 __wait_on_bit+0xac/0x2d0 kernel/sched/wait_bit.c:49 out_of_line_wait_on_bit+0x123/0x170 kernel/sched/wait_bit.c:64 wait_on_bit include/linux/wait_bit.h:76 [inline] gfs2_glock_wait+0xbd/0x2a0 fs/gfs2/glock.c:1380 gfs2_glock_nq_init fs/gfs2/glock.h:252 [inline] __gfs2_lookup+0x118/0x270 fs/gfs2/inode.c:905 __lookup_slow+0x281/0x3b0 fs/namei.c:1702 lookup_slow+0x53/0x70 fs/namei.c:1719 walk_component+0x2be/0x3f0 fs/namei.c:2010 lookup_last fs/namei.c:2467 [inline] path_lookupat+0x169/0x440 fs/namei.c:2491 filename_lookup+0x1f4/0x510 fs/namei.c:2520 user_path_at_empty+0x42/0x60 fs/namei.c:2917 user_path_at include/linux/namei.h:57 [inline] ksys_umount fs/namespace.c:1921 [inline] __do_sys_umount fs/namespace.c:1929 [inline] __se_sys_umount fs/namespace.c:1927 [inline] __x64_sys_umount+0xf5/0x170 fs/namespace.c:1927 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f9892d90a77 RSP: 002b:00007ffc4a9b2ff8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: ffffffffffffffda RBX: 00007f9892e13d7d RCX: 00007f9892d90a77 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc4a9b30b0 RBP: 00007ffc4a9b30b0 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc4a9b41a0 R13: 00007f9892e13d7d R14: 0000555590dec4a8 R15: 00007ffc4a9b6360 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 4 locks held by kworker/u4:8/2978: 2 locks held by getty/5528: #0: ffff88814c9f30a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217 1 lock held by syz-executor/5766: #0: ffff888058fbcb48 (&type->i_mutex_dir_key#27){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:814 [inline] #0: ffff888058fbcb48 (&type->i_mutex_dir_key#27){++++}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1718 2 locks held by kworker/1:4/5818: #0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc9000480fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc9000480fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 3 locks held by kworker/0:4/5831: #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc900048efd00 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc900048efd00 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline] #2: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x830 kernel/rcu/tree_exp.h:1004 3 locks held by syz.9.847/10865: #0: ffff88806a703470 (&fc->uapi_mutex){+.+.}-{3:3}, at: __do_sys_fsconfig fs/fsopen.c:479 [inline] #0: ffff88806a703470 (&fc->uapi_mutex){+.+.}-{3:3}, at: __se_sys_fsconfig+0x6d4/0x850 fs/fsopen.c:355 #1: ffff88807f1520e0 (&type->s_umount_key#32){++++}-{3:3}, at: vfs_cmd_reconfigure fs/fsopen.c:272 [inline] #1: ffff88807f1520e0 (&type->s_umount_key#32){++++}-{3:3}, at: vfs_fsconfig_locked+0x164/0x320 fs/fsopen.c:302 #2: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline] #2: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x830 kernel/rcu/tree_exp.h:1004 1 lock held by syz.9.847/10882: #0: ffff88807f1520e0 (&type->s_umount_key#32){++++}-{3:3}, at: do_remount fs/namespace.c:2924 [inline] #0: ffff88807f1520e0 (&type->s_umount_key#32){++++}-{3:3}, at: path_mount+0xcd3/0xfe0 fs/namespace.c:3705 1 lock held by cmp/10899: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf41/0xf80 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 5753 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:__bitmap_andnot+0x151/0x350 lib/bitmap.c:286 Code: 74 05 e8 22 f8 c0 fd 4d 8b 64 2f 08 4d 89 f7 49 8d 7c 2e 08 48 89 f8 48 c1 e8 03 4d 89 ee 42 80 3c 28 00 74 05 e8 ff f7 c0 fd <4d> 8b 6c 2f 08 48 8b 44 24 08 48 8d 7c 28 08 48 89 f8 48 c1 e8 03 RSP: 0018:ffffc900001f0b00 EFLAGS: 00000046 RAX: 1ffffffff21aa658 RBX: 0000000000000000 RCX: ffff88802e8abc00 RDX: 0000000000000100 RSI: 0000000000004000 RDI: ffffffff90d532c0 RBP: 000000000000ee50 R08: ffffffff907c469f R09: 0000000000000000 R10: ffffffff907c4610 R11: fffffbfff20f88d4 R12: 0000000000000000 R13: dffffc0000000000 R14: dffffc0000000000 R15: ffffffff90d44468 FS: 0000555568187500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f10f6a536bc CR3: 00000000761ea000 CR4: 00000000003506e0 Call Trace: bitmap_andnot include/linux/bitmap.h:367 [inline] __free_zapped_classes+0x2ae/0x2d0 kernel/locking/lockdep.c:6226 free_zapped_rcu+0xbe/0x240 kernel/locking/lockdep.c:6246 rcu_do_batch kernel/rcu/tree.c:2194 [inline] rcu_core+0xcc4/0x1720 kernel/rcu/tree.c:2467 handle_softirqs+0x280/0x820 kernel/softirq.c:578 do_softirq+0xed/0x180 kernel/softirq.c:479 __local_bh_enable_ip+0x178/0x1c0 kernel/softirq.c:406 tcp_recvmsg+0x220/0x810 net/ipv4/tcp.c:2605 inet_recvmsg+0x130/0x1e0 net/ipv4/af_inet.c:882 sock_recvmsg_nosec net/socket.c:1046 [inline] sock_recvmsg net/socket.c:1068 [inline] sock_read_iter+0x2b7/0x3b0 net/socket.c:1138 call_read_iter include/linux/fs.h:2012 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x431/0x920 fs/read_write.c:470 ksys_read+0x147/0x250 fs/read_write.c:613 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f82a218e11d Code: a8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb bd e8 a8 48 00 00 0f 1f 84 00 00 00 00 00 80 3d 41 d4 22 00 00 74 17 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 5b c3 66 2e 0f 1f 84 00 00 00 00 00 48 83 ec RSP: 002b:00007ffd766a7668 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f82a218e11d RDX: 0000000000000004 RSI: 00007ffd766a767c RDI: 0000000000000003 RBP: 0000000000000000 R08: 00000000000001ce R09: 0000000000745d1e R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd766a7a90 R13: 0000000000000004 R14: 00007ffd766a767c R15: 00007ffd766a7710