INFO: task syz.4.704:8031 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.704 state:D stack:25464 pid: 8031 ppid: 4185 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537 rwsem_down_read_slowpath+0x548/0x9d0 kernel/locking/rwsem.c:1055 __down_read_common kernel/locking/rwsem.c:1239 [inline] __down_read kernel/locking/rwsem.c:1252 [inline] down_read+0x96/0x2e0 kernel/locking/rwsem.c:1500 iterate_supers+0xa4/0x1d0 fs/super.c:716 quota_sync_all fs/quota/quota.c:68 [inline] __do_sys_quotactl fs/quota/quota.c:936 [inline] __se_sys_quotactl+0x33b/0x6f0 fs/quota/quota.c:915 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: 0033:0x7f18a66b6819 RSP: 002b:00007f18a48ef028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007f18a6930090 RCX: 00007f18a66b6819 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000100 RBP: 00007f18a674cc91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f18a6930128 R14: 00007f18a6930090 R15: 00007ffdcd943ac8 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c31eaa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/3959: #0: ffff88802c549098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc90002d032e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158 2 locks held by kworker/u4:6/4279: 2 locks held by kworker/1:11/4443: #0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc90005767d00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 1 lock held by udevd/5129: 4 locks held by syz.1.336/6034: #0: ffff888068e300e0 (&type->s_umount_key#25/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229 #1: ffffc900032c10f0 (&journal->j_mutex){+.+.}-{3:3}, at: reiserfs_mutex_lock_safe fs/reiserfs/reiserfs.h:814 [inline] #1: ffffc900032c10f0 (&journal->j_mutex){+.+.}-{3:3}, at: lock_journal fs/reiserfs/journal.c:534 [inline] #1: ffffc900032c10f0 (&journal->j_mutex){+.+.}-{3:3}, at: do_journal_end+0x304/0x42d0 fs/reiserfs/journal.c:4025 #2: ffffc900032c1180 (&journal->j_flush_mutex){+.+.}-{3:3}, at: reiserfs_mutex_lock_safe fs/reiserfs/reiserfs.h:814 [inline] #2: ffffc900032c1180 (&journal->j_flush_mutex){+.+.}-{3:3}, at: flush_journal_list+0x180/0x1ba0 fs/reiserfs/journal.c:1366 #3: ffff88805fe95890 (&jl->j_commit_mutex){+.+.}-{3:3}, at: reiserfs_mutex_lock_safe fs/reiserfs/reiserfs.h:814 [inline] #3: ffff88805fe95890 (&jl->j_commit_mutex){+.+.}-{3:3}, at: flush_commit_list+0x6de/0x1d70 fs/reiserfs/journal.c:1005 1 lock held by syz.4.704/8031: #0: ffff888068e300e0 (&type->s_umount_key#74){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716 1 lock held by syz.9.1111/10056: 1 lock held by syz.8.1138/10194: #0: ffffffff9669e8d8 (nfnl_subsys_ipset){+.+.}-{3:3}, at: nfnl_lock net/netfilter/nfnetlink.c:93 [inline] #0: ffffffff9669e8d8 (nfnl_subsys_ipset){+.+.}-{3:3}, at: nfnetlink_rcv_msg+0xa07/0x11f0 net/netfilter/nfnetlink.c:290 2 locks held by dhcpcd/10198: #0: ffff88807593a120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1744 [inline] #0: ffff88807593a120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x35/0xda0 net/packet/af_packet.c:3212 #1: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #1: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a5/0x750 kernel/rcu/tree_exp.h:845 1 lock held by dhcpcd/10199: #0: ffff88806816a120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1744 [inline] #0: ffff88806816a120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x35/0xda0 net/packet/af_packet.c:3212 2 locks held by dhcpcd/10202: #0: ffff88805e036120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1744 [inline] #0: ffff88805e036120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x35/0xda0 net/packet/af_packet.c:3212 #1: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #1: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a5/0x750 kernel/rcu/tree_exp.h:845 1 lock held by dhcpcd/10203: #0: ffff88807a6c4120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1744 [inline] #0: ffff88807a6c4120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x35/0xda0 net/packet/af_packet.c:3212 ============================================= 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 02/12/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a2/0x3d0 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: 5156 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:202 Code: 66 2e 0f 1f 84 00 00 00 00 00 53 48 89 fb e8 17 00 00 00 48 8b 3d 90 c4 10 0c 48 89 de 5b e9 b7 41 44 00 00 00 cc cc 00 00 cc <48> 8b 04 24 65 48 8b 0d a4 4e 89 7e 65 8b 15 a5 4e 89 7e 81 e2 00 RSP: 0018:ffffc9000330f7b8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff888019fed940 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000330f910 R08: ffffffff8d89e36f R09: 1ffffffff1b13c6d R10: dffffc0000000000 R11: fffffbfff1b13c6e R12: dffffc0000000000 R13: ffff88801d273652 R14: ffff88801d2737b0 R15: 00000000000000d8 FS: 000055555bad4500(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055d41084d660 CR3: 00000000685dc000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __find_get_block_slow fs/buffer.c:203 [inline] __find_get_block+0x41e/0x10a0 fs/buffer.c:1310 flush_commit_list+0xbf0/0x1d70 fs/reiserfs/journal.c:1051 do_journal_end+0x38ad/0x42d0 fs/reiserfs/journal.c:4372 reiserfs_sync_fs+0xe9/0x170 fs/reiserfs/super.c:78 sync_filesystem+0x1be/0x220 fs/sync.c:66 generic_shutdown_super+0x6b/0x300 fs/super.c:448 kill_block_super+0x7c/0xe0 fs/super.c:1427 deactivate_locked_super+0x93/0xf0 fs/super.c:335 cleanup_mnt+0x42d/0x4e0 fs/namespace.c:1148 task_work_run+0x125/0x1a0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f06aacf3a57 Code: a2 c7 05 9c fc 24 00 00 00 00 00 eb 96 e8 e1 12 00 00 90 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 RSP: 002b:00007ffd1b72a518 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f06aad88048 RCX: 00007f06aacf3a57 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd1b72a5d0 RBP: 00007ffd1b72a5d0 R08: 00007ffd1b72b5d0 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd1b72b660 R13: 00007f06aad88048 R14: 00000000000812a5 R15: 00007ffd1b72b6a0