INFO: task syz.1.27:5369 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.27 state:D stack:24960 pid: 5369 ppid: 5005 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_timeout+0x97/0x280 kernel/time/timer.c:1890 do_wait_for_common+0x29a/0x440 kernel/sched/completion.c:85 __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x48/0x60 kernel/sched/completion.c:138 kthread_stop+0x16e/0x540 kernel/kthread.c:666 gfs2_make_fs_ro+0x14c/0x5d0 fs/gfs2/super.c:533 signal_our_withdraw fs/gfs2/util.c:166 [inline] gfs2_withdraw+0x5f9/0x1460 fs/gfs2/util.c:343 gfs2_metatype_check_ii+0x74/0x90 fs/gfs2/util.c:520 gfs2_metatype_check_i fs/gfs2/util.h:129 [inline] gfs2_quota_init+0xc81/0xe80 fs/gfs2/quota.c:1406 gfs2_make_fs_rw+0x3f5/0x560 fs/gfs2/super.c:155 gfs2_fill_super+0x188a/0x1f50 fs/gfs2/ops_fstype.c:1276 get_tree_bdev+0x3f1/0x610 fs/super.c:1325 gfs2_get_tree+0x4d/0x1e0 fs/gfs2/ops_fstype.c:1332 vfs_get_tree+0x88/0x270 fs/super.c:1530 do_new_mount+0x24a/0xa40 fs/namespace.c:3034 do_mount fs/namespace.c:3377 [inline] __do_sys_mount fs/namespace.c:3585 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3562 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f57d501a90a RSP: 002b:00007f57d4289e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f57d4289ef0 RCX: 00007f57d501a90a RDX: 0000200000000400 RSI: 0000200000012500 RDI: 00007f57d4289eb0 RBP: 0000200000000400 R08: 00007f57d4289ef0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000012500 R13: 00007f57d4289eb0 R14: 00000000000125bb R15: 00002000000004c0 INFO: task gfs2_quotad:5378 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:gfs2_quotad state:D stack:27112 pid: 5378 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 bit_wait+0xd/0xc0 kernel/sched/wait_bit.c:199 __wait_on_bit kernel/sched/wait_bit.c:49 [inline] out_of_line_wait_on_bit+0x15e/0x200 kernel/sched/wait_bit.c:64 wait_on_bit include/linux/wait_bit.h:76 [inline] __gfs2_glock_dq+0x6b5/0xa10 fs/gfs2/glock.c:1588 gfs2_glock_dq fs/gfs2/glock.c:1652 [inline] gfs2_glock_dq_uninit+0x4f/0x110 fs/gfs2/glock.c:1672 gfs2_statfs_sync+0x6fa/0x780 fs/gfs2/super.c:310 quotad_check_timeo fs/gfs2/quota.c:1519 [inline] gfs2_quotad+0x365/0x880 fs/gfs2/quota.c:1581 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c11c720 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 1 lock held by udevd/3559: #0: ffff88801f85c518 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x157/0xa60 block/bdev.c:820 2 locks held by getty/3946: #0: ffff88814d922098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900026562e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158 1 lock held by udevd/4880: 2 locks held by kworker/1:16/4989: #0: ffff888016872138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc9000328fd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 3 locks held by kworker/1:18/4991: #0: ffff888016870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc9000338fd00 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffffffff8c1211a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #2: ffffffff8c1211a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x347/0x6b0 kernel/rcu/tree_exp.h:845 2 locks held by udevd/5022: #0: ffff88801f857918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x157/0xa60 block/bdev.c:820 #1: ffff888147c1e468 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_open+0x6a/0x100 drivers/block/loop.c:2056 1 lock held by syz.1.27/5369: #0: ffff8880278380e0 (&type->s_umount_key#53/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229 1 lock held by udevd/5546: #0: ffff88801f850918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x157/0xa60 block/bdev.c:820 2 locks held by udevd/6149: #0: ffff88801f85c518 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xf9/0x7d0 block/bdev.c:915 #1: ffff888147c21468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0xaa/0xb90 drivers/block/loop.c:1366 1 lock held by syz.4.433/6656: #0: ffff888147c1e468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0xaa/0xb90 drivers/block/loop.c:1366 2 locks held by syz.0.436/6660: #0: ffff88801f850918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xf9/0x7d0 block/bdev.c:915 #1: ffff88801f8e2468 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_release+0x4d/0x1f0 drivers/block/loop.c:2071 2 locks held by syz.2.438/6664: #0: ffff88801f854118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xf9/0x7d0 block/bdev.c:915 #1: ffff888147c18468 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_release+0x4d/0x1f0 drivers/block/loop.c:2071 1 lock held by syz.3.440/6668: #0: ffff88801f855d18 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x157/0xa60 block/bdev.c:820 1 lock held by syz.5.441/6670: #0: ffff88801f85c518 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x157/0xa60 block/bdev.c:820 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 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+0x168/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe0f/0xe50 kernel/hung_task.c:369 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 6672 Comm: syz.4.442 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x32/0x60 kernel/kcov.c:206 Code: a4 a3 8a 7e 65 8b 15 a5 a3 8a 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 34 16 00 00 00 74 2c 8b 91 10 16 00 00 <83> fa 02 75 21 48 8b 91 18 16 00 00 48 8b 32 48 8d 7e 01 8b 89 14 RSP: 0000:ffffc900061ffc50 EFLAGS: 00000246 RAX: ffffffff81b00d88 RBX: 0000000000000000 RCX: ffff8880209fd940 RDX: 0000000000000000 RSI: ffff88805630ea50 RDI: ffffea0001382900 RBP: dffffc0000000000 R08: dffffc0000000000 R09: ffffed100ee21891 R10: ffffed100ee21891 R11: 1ffff1100ee21890 R12: 00007fca9ed7b000 R13: ffff88805630ea50 R14: 0000000000000000 R15: ffffea0001382900 FS: 00007fcaa69096c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fca9ed7b000 CR3: 000000001eeb2000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: page_add_new_anon_rmap+0x28/0x8a0 mm/rmap.c:1184 do_anonymous_page mm/memory.c:3877 [inline] handle_pte_fault mm/memory.c:4648 [inline] __handle_mm_fault mm/memory.c:4785 [inline] handle_mm_fault+0x37c3/0x43b0 mm/memory.c:4883 do_user_addr_fault+0x489/0xc80 arch/x86/mm/fault.c:1357 handle_page_fault arch/x86/mm/fault.c:1445 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1501 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606 RIP: 0033:0x7fcaa755ac90 Code: 39 4f 08 72 4c 8d 4d ff 85 ed 74 33 66 0f 1f 44 00 00 48 39 f0 72 1b 4d 8b 07 49 89 c1 49 29 f1 47 0f b6 0c 08 45 84 c9 74 08 <45> 88 0c 00 49 8b 47 10 48 83 c0 01 49 89 47 10 83 e9 01 73 d3 41 RSP: 002b:00007fcaa69084a0 EFLAGS: 00010202 RAX: 0000000000892000 RBX: 00007fcaa6908540 RCX: 0000000000000101 RDX: 00000000000003ff RSI: 0000000000001000 RDI: 00007fcaa69085e0 RBP: 0000000000000102 R08: 00007fca9e4e9000 R09: 0000000000000001 R10: 0000200000037082 R11: 00000000000125b9 R12: 0000000000000c01 R13: 00007fcaa77343e0 R14: 0000000000000017 R15: 00007fcaa69085e0