INFO: task syz.4.327:6966 blocked for more than 143 seconds. Not tainted 6.15.0-syzkaller-11173-g546b1c9e93c2 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.327 state:D stack:25800 pid:6966 tgid:6964 ppid:5839 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 netfs_wait_for_request+0x1f0/0x600 fs/netfs/misc.c:450 netfs_unbuffered_write_iter_locked+0x52a/0x910 fs/netfs/direct_write.c:110 netfs_unbuffered_write_iter+0x4c4/0x660 fs/netfs/direct_write.c:193 do_iter_readv_writev+0x56b/0x7f0 fs/read_write.c:-1 vfs_writev+0x31a/0x960 fs/read_write.c:1057 do_writev+0x14d/0x2d0 fs/read_write.c:1103 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f48d4f8e969 RSP: 002b:00007f48d5e1e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 00007f48d51b5fa0 RCX: 00007f48d4f8e969 RDX: 0000000000000002 RSI: 0000200000000000 RDI: 0000000000000006 RBP: 00007f48d5010ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f48d51b5fa0 R15: 00007ffd160836e8 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e13f140 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13f140 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13f140 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 4 locks held by kworker/1:2/1212: 2 locks held by getty/5585: #0: ffff888030dd10a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 2 locks held by kworker/0:3/5826: 3 locks held by syz.4.327/6966: #0: ffff88802a5ba638 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x247/0x320 fs/file.c:1213 #1: ffff888029f88428 (sb_writers#17){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3092 [inline] #1: ffff888029f88428 (sb_writers#17){.+.+}-{0:0}, at: vfs_writev+0x288/0x960 fs/read_write.c:1055 #2: ffff888057ac8148 (&sb->s_type->i_mutex_key#23){++++}-{4:4}, at: netfs_start_io_direct+0x1ef/0x230 fs/netfs/locking.c:188 2 locks held by syz.3.617/8118: 2 locks held by syz.1.636/8197: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-syzkaller-11173-g546b1c9e93c2 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:470 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 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: 12 Comm: kworker/u8:0 Not tainted 6.15.0-syzkaller-11173-g546b1c9e93c2 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210 Code: 89 fb e8 23 00 00 00 48 8b 3d b4 c7 f7 0b 48 89 de 5b e9 f3 8e 56 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 08 d0 98 92 65 8b 15 98 83 RSP: 0018:ffffc90000117930 EFLAGS: 00000246 RAX: ffffffff893d4b53 RBX: ffff88802abe6b40 RCX: ffff88801d29da00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000001 R08: ffffffff8f9fb8f7 R09: 1ffffffff1f3f71e R10: dffffc0000000000 R11: fffffbfff1f3f71f R12: dffffc0000000000 R13: 1ffff1100557cd73 R14: 0000000000000000 R15: 1ffff1100557cd74 FS: 0000000000000000(0000) GS:ffff888125d93000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000030000 CR3: 00000000354e8000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: nf_conntrack_put include/linux/netfilter/nf_conntrack_common.h:36 [inline] skb_release_head_state+0x175/0x250 net/core/skbuff.c:1142 skb_release_all net/core/skbuff.c:1150 [inline] __kfree_skb net/core/skbuff.c:1166 [inline] consume_skb+0x60/0xf0 net/core/skbuff.c:1398 nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline] nsim_dev_trap_report_work+0x7cf/0xb80 drivers/net/netdevsim/dev.c:851 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245