INFO: task syz.0.1299:10187 blocked for more than 143 seconds. Not tainted 6.15.0-next-20250530-syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.1299 state:D stack:25176 pid:10187 tgid:10185 ppid:5833 task_flags:0x400548 flags:0x00024000 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:148 io_wq_exit_workers io_uring/io-wq.c:1317 [inline] io_wq_put_and_exit+0x31b/0x690 io_uring/io-wq.c:1345 io_uring_clean_tctx+0x11f/0x1a0 io_uring/tctx.c:203 io_uring_cancel_generic+0x68f/0x730 io_uring/io_uring.c:3204 io_uring_files_cancel include/linux/io_uring.h:19 [inline] do_exit+0x345/0x22e0 kernel/exit.c:911 do_group_exit+0x21c/0x2d0 kernel/exit.c:1104 get_signal+0x1286/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:111 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8f2b78e969 RSP: 002b:00007f8f2c5480e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f8f2b9b5fa8 RCX: 00007f8f2b78e969 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f8f2b9b5fa8 RBP: 00007f8f2b9b5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f8f2b9b5fac R13: 0000000000000000 R14: 00007ffed9281e70 R15: 00007ffed9281f58 Showing all locks held in the system: 2 locks held by ksoftirqd/0/15: 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 2 locks held by getty/5595: #0: ffff8880306150a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036bb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 3 locks held by kworker/u8:10/5972: #0: ffff8880b863b918 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:614 #1: ffff8880b8623f08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x314/0x6d0 kernel/sched/psi.c:975 #2: ffff8880b8625958 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x8ee/0xf30 kernel/time/timer.c:1117 1 lock held by iou-wrk-10187/10193: #0: ffff888079fdc0a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_ring_submit_lock io_uring/io_uring.h:287 [inline] #0: ffff888079fdc0a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_manage_buffers_legacy+0xa33/0xc90 io_uring/kbuf.c:549 1 lock held by iou-wrk-10187/10195: #0: ffff888079fdc0a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_ring_submit_lock io_uring/io_uring.h:287 [inline] #0: ffff888079fdc0a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_manage_buffers_legacy+0xa33/0xc90 io_uring/kbuf.c:549 1 lock held by iou-wrk-10187/10197: #0: ffff888079fdc0a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_ring_submit_lock io_uring/io_uring.h:287 [inline] #0: ffff888079fdc0a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_manage_buffers_legacy+0xa33/0xc90 io_uring/kbuf.c:549 1 lock held by iou-wrk-10187/10199: #0: ffff888079fdc0a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_ring_submit_lock io_uring/io_uring.h:287 [inline] #0: ffff888079fdc0a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_manage_buffers_legacy+0xa33/0xc90 io_uring/kbuf.c:549 1 lock held by iou-wrk-10187/10200: 1 lock held by iou-wrk-10187/10202: #0: ffff888079fdc0a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_ring_submit_lock io_uring/io_uring.h:287 [inline] #0: ffff888079fdc0a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_manage_buffers_legacy+0xa33/0xc90 io_uring/kbuf.c:549 1 lock held by iou-wrk-10187/10203: #0: ffff888079fdc0a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_ring_submit_lock io_uring/io_uring.h:287 [inline] #0: ffff888079fdc0a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_manage_buffers_legacy+0xa33/0xc90 io_uring/kbuf.c:549 1 lock held by iou-wrk-10187/10204: #0: ffff888079fdc0a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_ring_submit_lock io_uring/io_uring.h:287 [inline] #0: ffff888079fdc0a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_manage_buffers_legacy+0xa33/0xc90 io_uring/kbuf.c:549 2 locks held by syz.5.1812/11849: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-next-20250530-syzkaller #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+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 6039 Comm: kworker/u8:12 Not tainted 6.15.0-next-20250530-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: bat_events batadv_nc_worker RIP: 0010:check_wait_context kernel/locking/lockdep.c:4873 [inline] RIP: 0010:__lock_acquire+0x45c/0xd20 kernel/locking/lockdep.c:5190 Code: f9 ff bd ff ff ff ff 0f 4c e9 ff c5 45 8d 7c 24 01 49 ff cc 44 89 f9 83 c1 fe 78 44 44 89 e3 81 e3 ff ff ff 7f 83 f9 31 73 1d <48> 8d 0c 9b 8b 8c cf 10 0b 00 00 31 c1 41 ff cf 49 ff cc f7 c1 00 RSP: 0018:ffffc9000a8b78f0 EFLAGS: 00000097 RAX: 0000000000020007 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000003 RSI: 0000000000000000 RDI: ffff88802e703c00 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8b33b452 R10: dffffc0000000000 R11: ffffffff8b33b380 R12: 0000000000000000 R13: 0000000000000001 R14: ffff88802e704740 R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff888125c53000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6f6e77fab8 CR3: 000000000df38000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0xef/0x610 net/batman-adv/network-coding.c:719 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+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245