INFO: task syz.5.1874:13104 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.1874 state:D stack:23032 pid:13104 tgid:13102 ppid:9027 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6740 kernel/sched/core.c:7239 __schedule_loop kernel/sched/core.c:7316 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7331 super_lock+0x286/0x3f0 fs/super.c:118 __iterate_supers+0x38b/0x4a0 fs/super.c:994 quota_sync_all fs/quota/quota.c:69 [inline] __do_sys_quotactl fs/quota/quota.c:938 [inline] __se_sys_quotactl fs/quota/quota.c:917 [inline] __x64_sys_quotactl+0x2b3/0x400 fs/quota/quota.c:917 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5a8e39e0d9 RSP: 002b:00007f5a8f223028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007f5a8e626090 RCX: 00007f5a8e39e0d9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000101 RBP: 00007f5a8e435024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5a8e626128 R14: 00007f5a8e626090 R15: 00007ffc9d0264b8 Showing all locks held in the system: locks held by khungtaskd/31: 1, last CPU#0: #0: ffffffff8ede9440 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8ede9440 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8ede9440 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6793 locks held by syz.3.744/8853: 1, on CPU#1: #0: ffff888033c1e0e8 (&type->s_umount_key#90/1){+.+.}-{4:4}, at: alloc_super fs/super.c:365 [inline] #0: ffff888033c1e0e8 (&type->s_umount_key#90/1){+.+.}-{4:4}, at: sget_fc+0x3c2/0x1f20 fs/super.c:889 locks held by syz-executor/13916: 1, last CPU#1: #0: ffffffff8ede9440 (rcu_read_lock){....}-{1:3}, at: srcu_lock_acquire include/linux/srcu.h:187 [inline] #0: ffffffff8ede9440 (rcu_read_lock){....}-{1:3}, at: srcu_read_lock include/linux/srcu.h:294 [inline] #0: ffffffff8ede9440 (rcu_read_lock){....}-{1:3}, at: tomoyo_read_lock security/tomoyo/common.h:1112 [inline] #0: ffffffff8ede9440 (rcu_read_lock){....}-{1:3}, at: tomoyo_check_open_permission+0x169/0x3c0 security/tomoyo/file.c:772 locks held by syz.7.2193/14529: 3, on CPU#0: #0: ffff88807f291430 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1259 #1: ffff88807c4b2460 (sb_writers#10){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:739 #2: ffff88804755e080 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:336 locks held by syz.7.2193/14579: 2, on CPU#0: #0: ffff88802ca85cf8 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:183 #1: ffff88804755e080 (&of->mutex){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:165 locks held by getty/15088: 2, on CPU#1: #0: ffff8880380360a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900036b32e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:122 nmi_trigger_cpumask_backtrace+0x21f/0x2a0 lib/nmi_backtrace.c:65 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x141/0x190 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xcb1/0x1030 kernel/hung_task.c:561 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x730/0xd60 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: 4953 Comm: klogd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:__lock_acquire+0xb8/0x1ec0 kernel/locking/lockdep.c:5154 Code: dd 9e 12 83 fb 01 0f 87 37 03 00 00 89 d8 0f 87 6a 19 00 00 49 8b 44 c7 08 48 85 c0 0f 84 21 03 00 00 45 8b 94 24 a0 0b 00 00 <41> 83 fa 2f 76 09 40 84 ed 0f 85 d5 10 00 00 48 2d e0 7d 89 96 48 RSP: 0018:ffffc90003457a70 EFLAGS: 00000082 RAX: ffffffff968ae3b0 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88801c1536b8 RBP: 0000000094891b01 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffff88807eb3a580 R13: 0000000000000001 R14: 0000000000000000 R15: ffff88801c1536b8 FS: 00007fe62ef99c80(0000) GS:ffff888123cd4000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb13efef2f8 CR3: 000000007e97e000 CR4: 00000000003526f0 Call Trace: lock_acquire kernel/locking/lockdep.c:5886 [inline] lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5843 __might_fault+0xde/0x140 mm/memory.c:7292 _inline_copy_to_user include/linux/uaccess.h:197 [inline] _copy_to_user+0x2d/0xd0 lib/usercopy.c:24 copy_to_user include/linux/uaccess.h:230 [inline] syslog_print+0x360/0x620 kernel/printk/printk.c:1662 do_syslog+0x5bd/0x6d0 kernel/printk/printk.c:1763 __do_sys_syslog kernel/printk/printk.c:1855 [inline] __se_sys_syslog kernel/printk/printk.c:1853 [inline] __x64_sys_syslog+0x74/0xb0 kernel/printk/printk.c:1853 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe62f163a37 Code: 73 01 c3 48 8b 0d c1 f3 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 67 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 91 f3 0c 00 f7 d8 64 89 01 48 RSP: 002b:00007ffd608be0e8 EFLAGS: 00000206 ORIG_RAX: 0000000000000067 RAX: ffffffffffffffda RBX: 00007fe62f303490 RCX: 00007fe62f163a37 RDX: 00000000000003ff RSI: 00007fe62f303490 RDI: 0000000000000002 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000004000 R11: 0000000000000206 R12: 00007fe62f303490 R13: 00007fe62f2e0dfe R14: 00007fe62f3034ab R15: 00007fe62f3034ab