Hello, syzbot found the following issue on: HEAD commit: b3a3cbde Add linux-next specific files for 20210115 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=1290cb3f500000 kernel config: https://syzkaller.appspot.com/x/.config?x=6ea08dae6aab586f dashboard link: https://syzkaller.appspot.com/bug?extid=e45cf80926482af211a0 compiler: gcc (GCC) 10.1.0-syz 20200507 Unfortunately, I don't have any reproducer for this issue yet. IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+e45cf80926482af211a0@xxxxxxxxxxxxxxxxxxxxxxxxx INFO: task kworker/0:1H:3061 blocked for more than 143 seconds. Not tainted 5.11.0-rc3-next-20210115-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:1H state:D stack:27904 pid: 3061 ppid: 2 flags:0x00004000 Workqueue: glock_workqueue glock_work_func Call Trace: context_switch kernel/sched/core.c:4373 [inline] __schedule+0x90c/0x21a0 kernel/sched/core.c:5124 schedule+0xcf/0x270 kernel/sched/core.c:5203 rwsem_down_write_slowpath+0x7e5/0x1200 kernel/locking/rwsem.c:1106 __down_write_common kernel/locking/rwsem.c:1261 [inline] __down_write_common kernel/locking/rwsem.c:1258 [inline] __down_write kernel/locking/rwsem.c:1270 [inline] down_write+0x132/0x150 kernel/locking/rwsem.c:1407 freeze_super+0x41/0x330 fs/super.c:1663 freeze_go_sync+0x1e2/0x330 fs/gfs2/glops.c:588 do_xmote+0x2ff/0xbc0 fs/gfs2/glock.c:616 run_queue+0x323/0x680 fs/gfs2/glock.c:753 glock_work_func+0xff/0x3f0 fs/gfs2/glock.c:920 process_one_work+0x98d/0x15f0 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 INFO: task syz-executor.1:24203 can't die for more than 143 seconds. task:syz-executor.1 state:D stack:25656 pid:24203 ppid: 23040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4373 [inline] __schedule+0x90c/0x21a0 kernel/sched/core.c:5124 schedule+0xcf/0x270 kernel/sched/core.c:5203 schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1868 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x163/0x260 kernel/sched/completion.c:138 flush_workqueue+0x3ff/0x13e0 kernel/workqueue.c:2838 gfs2_gl_hash_clear+0xc8/0x270 fs/gfs2/glock.c:1984 gfs2_fill_super+0x2073/0x2720 fs/gfs2/ops_fstype.c:1231 get_tree_bdev+0x440/0x760 fs/super.c:1291 gfs2_get_tree+0x4a/0x270 fs/gfs2/ops_fstype.c:1254 vfs_get_tree+0x89/0x2f0 fs/super.c:1496 do_new_mount fs/namespace.c:2889 [inline] path_mount+0x12ae/0x1e70 fs/namespace.c:3220 do_mount fs/namespace.c:3233 [inline] __do_sys_mount fs/namespace.c:3441 [inline] __se_sys_mount fs/namespace.c:3418 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3418 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x460c6a RSP: 002b:00007f8f38606a78 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f8f38606b10 RCX: 0000000000460c6a RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f8f38606ad0 RBP: 00007f8f38606ad0 R08: 00007f8f38606b10 R09: 0000000020000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000020000000 R13: 0000000020000100 R14: 0000000020000200 R15: 0000000020047a20 INFO: task syz-executor.1:24203 blocked for more than 143 seconds. Not tainted 5.11.0-rc3-next-20210115-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.1 state:D stack:25656 pid:24203 ppid: 23040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4373 [inline] __schedule+0x90c/0x21a0 kernel/sched/core.c:5124 schedule+0xcf/0x270 kernel/sched/core.c:5203 schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1868 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x163/0x260 kernel/sched/completion.c:138 flush_workqueue+0x3ff/0x13e0 kernel/workqueue.c:2838 gfs2_gl_hash_clear+0xc8/0x270 fs/gfs2/glock.c:1984 gfs2_fill_super+0x2073/0x2720 fs/gfs2/ops_fstype.c:1231 get_tree_bdev+0x440/0x760 fs/super.c:1291 gfs2_get_tree+0x4a/0x270 fs/gfs2/ops_fstype.c:1254 vfs_get_tree+0x89/0x2f0 fs/super.c:1496 do_new_mount fs/namespace.c:2889 [inline] path_mount+0x12ae/0x1e70 fs/namespace.c:3220 do_mount fs/namespace.c:3233 [inline] __do_sys_mount fs/namespace.c:3441 [inline] __se_sys_mount fs/namespace.c:3418 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3418 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x460c6a RSP: 002b:00007f8f38606a78 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f8f38606b10 RCX: 0000000000460c6a RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f8f38606ad0 RBP: 00007f8f38606ad0 R08: 00007f8f38606b10 R09: 0000000020000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000020000000 R13: 0000000020000100 R14: 0000000020000200 R15: 0000000020047a20 Showing all locks held in the system: 1 lock held by khungtaskd/1662: #0: ffffffff8b370ee0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6259 3 locks held by kworker/0:1H/3061: #0: ffff888142ecf538 ((wq_completion)glock_workqueue){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888142ecf538 ((wq_completion)glock_workqueue){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff888142ecf538 ((wq_completion)glock_workqueue){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888142ecf538 ((wq_completion)glock_workqueue){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff888142ecf538 ((wq_completion)glock_workqueue){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff888142ecf538 ((wq_completion)glock_workqueue){+.+.}-{0:0}, at: process_one_work+0x871/0x15f0 kernel/workqueue.c:2246 #1: ffffc90001edfda8 ((work_completion)(&(&gl->gl_work)->work)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x15f0 kernel/workqueue.c:2250 #2: ffff8880718c60e0 (&type->s_umount_key#82){+.+.}-{3:3}, at: freeze_super+0x41/0x330 fs/super.c:1663 1 lock held by in:imklog/8137: #0: ffff88801813d270 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:947 2 locks held by agetty/8141: #0: ffff888019119098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:266 #1: ffffc90000f292e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x21d/0x1aa0 drivers/tty/n_tty.c:2160 2 locks held by syz-executor.5/11026: #0: ffff88806d6b6098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:266 #1: ffffc900092fb2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x21d/0x1aa0 drivers/tty/n_tty.c:2160 2 locks held by syz-executor.5/11065: #0: ffff88806bc46098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:266 #1: ffffc90009b352e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x21d/0x1aa0 drivers/tty/n_tty.c:2160 2 locks held by syz-executor.5/11122: #0: ffff88806f7e7098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:266 #1: ffffc90009d232e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x21d/0x1aa0 drivers/tty/n_tty.c:2160 2 locks held by syz-executor.5/11177: #0: ffff88806fc18098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:266 #1: ffffc900010ca2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x21d/0x1aa0 drivers/tty/n_tty.c:2160 1 lock held by syz-executor.1/24203: #0: ffff8880718c60e0 (&type->s_umount_key#81/1){+.+.}-{3:3}, at: alloc_super+0x201/0xaf0 fs/super.c:229 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1662 Comm: khungtaskd Not tainted 5.11.0-rc3-next-20210115-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:147 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:253 [inline] watchdog+0xd89/0xf30 kernel/hung_task.c:338 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4866 Comm: systemd-journal Not tainted 5.11.0-rc3-next-20210115-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:native_restore_fl arch/x86/include/asm/irqflags.h:41 [inline] RIP: 0010:arch_local_irq_restore arch/x86/include/asm/irqflags.h:84 [inline] RIP: 0010:lock_is_held_type+0xe7/0x120 kernel/locking/lockdep.c:5483 Code: e0 03 44 39 f0 41 0f 94 c5 48 c7 c7 a0 96 4b 89 e8 ce 0c 00 00 b8 ff ff ff ff 65 0f c1 05 e1 bc 06 77 83 f8 01 75 1b ff 34 24 <9d> 48 83 c4 08 44 89 e8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 45 31 ed RSP: 0018:ffffc9000160fec0 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffffff8b370e20 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff8178e0b5 R11: 0000000000000000 R12: ffff88801170b800 R13: 0000000000000000 R14: 00000000ffffffff R15: 0000000000000000 FS: 00007fdfb845b8c0(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fdfb5904000 CR3: 0000000026029000 CR4: 00000000001526e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_is_held include/linux/lockdep.h:271 [inline] rcu_read_lock_sched_held+0x3a/0x70 kernel/rcu/update.c:125 trace_irq_disable include/trace/events/preemptirq.h:36 [inline] trace_hardirqs_off_finish kernel/trace/trace_preemptirq.c:67 [inline] trace_hardirqs_off_finish+0x224/0x270 kernel/trace/trace_preemptirq.c:61 __enter_from_user_mode kernel/entry/common.c:25 [inline] syscall_enter_from_user_mode+0x18/0x50 kernel/entry/common.c:106 do_syscall_64+0xf/0x70 arch/x86/entry/common.c:41 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7fdfb77179c7 Code: 83 c4 08 48 3d 01 f0 ff ff 73 01 c3 48 8b 0d c8 d4 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 b8 15 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a1 d4 2b 00 f7 d8 64 89 01 48 RSP: 002b:00007fffdb006028 EFLAGS: 00000246 ORIG_RAX: 0000000000000015 RAX: ffffffffffffffda RBX: 00007fffdb008f40 RCX: 00007fdfb77179c7 RDX: 00007fdfb8188a00 RSI: 0000000000000000 RDI: 000055ae1d4fc9a3 RBP: 00007fffdb006060 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fffdb008f40 R15: 00007fffdb006550 --- This report is generated by a bot. 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