INFO: task syz.0.18:6635 blocked in I/O wait for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.18 state:D stack:25752 pid:6635 tgid:6635 ppid:6465 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x169e/0x54f0 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x164/0x360 kernel/sched/core.c:7283 io_schedule+0x7f/0xd0 kernel/sched/core.c:8110 folio_wait_bit_common+0x6dd/0xbc0 mm/filemap.c:1324 folio_lock include/linux/pagemap.h:1159 [inline] writeback_get_folio mm/page-writeback.c:2435 [inline] writeback_iter+0x8d8/0x1290 mm/page-writeback.c:2529 iomap_writepages+0x152/0x2e0 fs/iomap/buffered-io.c:1958 gfs2_writepages+0x1bb/0x2a0 fs/gfs2/aops.c:175 do_writepages+0x32e/0x550 mm/page-writeback.c:2571 filemap_writeback mm/filemap.c:388 [inline] filemap_fdatawrite_range mm/filemap.c:413 [inline] filemap_fdatawrite+0x1ec/0x2f0 mm/filemap.c:419 gfs2_ordered_write fs/gfs2/log.c:730 [inline] __gfs2_log_flush+0x85b/0x1dc0 fs/gfs2/log.c:1134 gfs2_log_flush+0x34/0x50 fs/gfs2/log.c:1216 gfs2_trans_end+0x37b/0x570 fs/gfs2/trans.c:163 gfs2_page_mkwrite+0x1529/0x18f0 fs/gfs2/file.c:535 do_page_mkwrite+0x150/0x310 mm/memory.c:3668 do_shared_fault mm/memory.c:5971 [inline] do_fault mm/memory.c:6033 [inline] do_pte_missing+0x736/0x2940 mm/memory.c:4550 handle_pte_fault mm/memory.c:6414 [inline] __handle_mm_fault mm/memory.c:6552 [inline] handle_mm_fault+0xdb5/0x14c0 mm/memory.c:6721 do_user_addr_fault+0xa73/0x1340 arch/x86/mm/fault.c:1334 handle_page_fault arch/x86/mm/fault.c:1474 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7fafec2b5585 RSP: 002b:00007fffbb0b1b30 EFLAGS: 00010246 RAX: 0000200000000180 RBX: 0000000000000008 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00005555767393d8 RBP: 00007fffbb0b1c50 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 00007fffbb0b1c90 R13: 00007fafec625fac R14: 000000000002838d R15: 00007fafec625fa0 Showing all locks held in the system: 1 lock held by khungtaskd/39: #0: ffffffff8dfc8180 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8dfc8180 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8dfc8180 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6777 2 locks held by kworker/u8:2/44: #0: ffff88813fe7c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x890/0x1710 kernel/workqueue.c:3284 #1: ffffc90000b67c40 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work+0x8b7/0x1710 kernel/workqueue.c:3285 4 locks held by kworker/u8:7/159: #0: ffff88801f6c5138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x890/0x1710 kernel/workqueue.c:3284 #1: ffffc90003a07c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x8b7/0x1710 kernel/workqueue.c:3285 #2: ffff888039fac0d0 (&type->s_umount_key#55){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:565 #3: ffff8880329311a0 (&sdp->sd_log_flush_lock){++++}-{4:4}, at: gfs2_log_flush+0x27/0x50 fs/gfs2/log.c:1215 2 locks held by kworker/u8:8/753: #0: ffff88813fe7c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x890/0x1710 kernel/workqueue.c:3284 #1: ffffc90003c17c40 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work+0x8b7/0x1710 kernel/workqueue.c:3285 2 locks held by getty/5366: #0: ffff88803265d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003cbe2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211 4 locks held by syz.0.18/6635: #0: ffff888045380808 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:310 #1: ffff888039fac5f8 (sb_pagefaults#2){.+.+}-{0:0}, at: do_page_mkwrite+0x150/0x310 mm/memory.c:3668 #2: ffff888039fac770 (sb_internal#2){.+.+}-{0:0}, at: gfs2_trans_begin+0x6f/0xe0 fs/gfs2/trans.c:123 #3: ffff8880329311a0 (&sdp->sd_log_flush_lock){++++}-{4:4}, at: gfs2_log_flush+0x27/0x50 fs/gfs2/log.c:1215 1 lock held by gfs2_logd/syz:s/6639: #0: ffff8880329311a0 (&sdp->sd_log_flush_lock){++++}-{4:4}, at: gfs2_logd+0x2ac/0x1180 fs/gfs2/log.c:1351 2 locks held by gfs2_quotad/syz/6640: #0: ffff888039fac770 (sb_internal#2){.+.+}-{0:0}, at: gfs2_trans_begin+0x6f/0xe0 fs/gfs2/trans.c:123 #1: ffff8880329311a0 (&sdp->sd_log_flush_lock){++++}-{4:4}, at: __gfs2_trans_begin+0x51e/0x910 fs/gfs2/trans.c:87 1 lock held by udevd/6647: #0: ffffffff8dfc8180 (rcu_read_lock){....}-{1:3}, at: srcu_lock_acquire include/linux/srcu.h:187 [inline] #0: ffffffff8dfc8180 (rcu_read_lock){....}-{1:3}, at: srcu_read_lock include/linux/srcu.h:294 [inline] #0: ffffffff8dfc8180 (rcu_read_lock){....}-{1:3}, at: tomoyo_read_lock security/tomoyo/common.h:1112 [inline] #0: ffffffff8dfc8180 (rcu_read_lock){....}-{1:3}, at: tomoyo_check_open_permission+0x1d3/0x470 security/tomoyo/file.c:772 2 locks held by syz.1.263/7674: #0: ffff8880445926c8 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:310 #1: ffffffff8dfc8180 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #1: ffffffff8dfc8180 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #1: ffffffff8dfc8180 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x200 mm/pgtable-generic.c:290 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 39 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd3/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 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: 6647 Comm: udevd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:stack_trace_consume_entry+0x7/0x280 kernel/stacktrace.c:83 Code: cc cc cc cc e8 fa 80 77 09 66 2e 0f 1f 84 00 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 18 48 ba 00 00 00 00 00 fc ff df 4c RSP: 0018:ffffc90003d27490 EFLAGS: 00000286 RAX: ffffffff82228655 RBX: ffffc90003d27560 RCX: 0000000000000000 RDX: 0000000000000001 RSI: ffffffff82228655 RDI: ffffc90003d27560 RBP: ffffc90003d27530 R08: ffffc90003d27850 R09: 0000000000000000 R10: ffffc90003d274f8 R11: ffffffff81afb320 R12: ffff88802f680000 R13: 0000000000000000 R14: ffffffff81afb320 R15: ffffc90003d274a8 FS: 00007fb5d5535880(0000) GS:ffff88812602a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f93fc9dd000 CR3: 000000004071a000 CR4: 00000000003526f0 Call Trace: arch_stack_walk+0x10f/0x150 arch/x86/kernel/stacktrace.c:27 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2700 [inline] slab_free mm/slub.c:6258 [inline] kfree+0x1c5/0x6c0 mm/slub.c:6573 tomoyo_realpath_from_path+0x598/0x5d0 security/tomoyo/realpath.c:286 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x283/0x560 security/tomoyo/file.c:827 security_inode_getattr+0x12b/0x310 security/security.c:1895 vfs_getattr+0x23/0x70 fs/stat.c:259 vfs_statx_path+0x2b/0x230 fs/stat.c:299 vfs_statx+0x12e/0x200 fs/stat.c:356 vfs_fstatat+0x11b/0x170 fs/stat.c:373 __do_sys_newfstatat fs/stat.c:538 [inline] __se_sys_newfstatat fs/stat.c:532 [inline] __x64_sys_newfstatat+0x151/0x200 fs/stat.c:532 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb5d568db0a Code: 48 8b 15 f1 f2 0d 00 f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 41 89 ca b8 06 01 00 00 0f 05 <3d> 00 f0 ff ff 77 07 31 c0 c3 0f 1f 40 00 48 8b 15 b9 f2 0d 00 f7 RSP: 002b:00007ffc3b66f338 EFLAGS: 00000202 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 00007ffc3b66fd10 RCX: 00007fb5d568db0a RDX: 00007ffc3b66f360 RSI: 00007ffc3b66fd10 RDI: 00000000ffffff9c RBP: 00007ffc3b66fd1f R08: 0000000000000075 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000202 R12: 0000558dbf34f2e5 R13: 00007ffc3b66f3f0 R14: 0000558dba3016d7 R15: 0000558dbf34f2e0 ---------------- Code disassembly (best guess): 0: cc int3 1: cc int3 2: cc int3 3: cc int3 4: e8 fa 80 77 09 call 0x9778103 9: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1) 10: 00 00 00 13: 90 nop 14: 90 nop 15: 90 nop 16: 90 nop 17: 90 nop 18: 90 nop 19: 90 nop 1a: 90 nop 1b: 90 nop 1c: 90 nop 1d: 90 nop 1e: 90 nop 1f: 90 nop 20: 90 nop 21: 90 nop 22: 90 nop 23: f3 0f 1e fa endbr64 27: 55 push %rbp 28: 41 57 push %r15 * 2a: 41 56 push %r14 <-- trapping instruction 2c: 41 55 push %r13 2e: 41 54 push %r12 30: 53 push %rbx 31: 48 83 ec 18 sub $0x18,%rsp 35: 48 ba 00 00 00 00 00 movabs $0xdffffc0000000000,%rdx 3c: fc ff df 3f: 4c rex.WR