INFO: task syz.1.750:9541 blocked for more than 143 seconds. Tainted: G U 6.14.0-rc2-syzkaller-00034-gfebbc555cf0f #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.750 state:D stack:27248 pid:9541 tgid:9540 ppid:5831 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5377 [inline] __schedule+0xf43/0x5890 kernel/sched/core.c:6764 __schedule_loop kernel/sched/core.c:6841 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6856 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6913 __mutex_lock_common kernel/locking/mutex.c:662 [inline] __mutex_lock+0x6bd/0xb10 kernel/locking/mutex.c:730 nfsd_nl_threads_set_doit+0x694/0xbe0 fs/nfsd/nfsctl.c:1629 genl_family_rcv_msg_doit+0x202/0x2f0 net/netlink/genetlink.c:1115 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0x565/0x800 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x165/0x410 net/netlink/af_netlink.c:2543 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline] netlink_unicast+0x53c/0x7f0 net/netlink/af_netlink.c:1348 netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1892 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:733 [inline] ____sys_sendmsg+0x9ae/0xb40 net/socket.c:2573 ___sys_sendmsg+0x135/0x1e0 net/socket.c:2627 __sys_sendmsg+0x16e/0x220 net/socket.c:2659 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff99e38cde9 RSP: 002b:00007ff99f268038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007ff99e5a5fa0 RCX: 00007ff99e38cde9 RDX: 0000000000000840 RSI: 0000400000000240 RDI: 0000000000000003 RBP: 00007ff99e40e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ff99e5a5fa0 R15: 00007fff8448ccf8 INFO: task syz.4.776:9617 blocked for more than 144 seconds. Tainted: G U 6.14.0-rc2-syzkaller-00034-gfebbc555cf0f #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.776 state:D stack:27952 pid:9617 tgid:9614 ppid:7780 task_flags:0x400140 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5377 [inline] __schedule+0xf43/0x5890 kernel/sched/core.c:6764 __schedule_loop kernel/sched/core.c:6841 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6856 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6913 __mutex_lock_common kernel/locking/mutex.c:662 [inline] __mutex_lock+0x6bd/0xb10 kernel/locking/mutex.c:730 expkey_flush+0x18/0x90 fs/nfsd/export.c:252 write_flush.constprop.0+0x2a1/0x3a0 net/sunrpc/cache.c:1549 pde_write fs/proc/inode.c:330 [inline] proc_reg_write+0x23d/0x330 fs/proc/inode.c:342 do_loop_readv_writev fs/read_write.c:843 [inline] do_loop_readv_writev fs/read_write.c:828 [inline] vfs_writev+0x6da/0xdd0 fs/read_write.c:1052 do_writev+0x133/0x340 fs/read_write.c:1096 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8f5f98cde9 RSP: 002b:00007f8f60757038 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 00007f8f5fba6160 RCX: 00007f8f5f98cde9 RDX: 0000000000000002 RSI: 0000400000000200 RDI: 0000000000000004 RBP: 00007f8f5fa0e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f8f5fba6160 R15: 00007ffcdd3a4cc8 Showing all locks held in the system: 1 lock held by pool_workqueue_/3: #0: ffffffff8e1c75b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a4/0x3b0 kernel/rcu/tree_exp.h:334 1 lock held by khungtaskd/30: #0: ffffffff8e1bc140 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e1bc140 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e1bc140 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6746 5 locks held by kworker/u8:10/6895: 1 lock held by syz.2.327/7507: 2 locks held by kworker/u8:13/7750: 2 locks held by getty/9036: #0: ffff88814d2790a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc90002ed22f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211 2 locks held by syz.0.717/9417: #0: ffffffff8ff79070 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e5bda88 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xe3/0x1b40 fs/nfsd/nfsctl.c:1922 2 locks held by syz.1.750/9541: #0: ffffffff8ff79070 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e5bda88 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x694/0xbe0 fs/nfsd/nfsctl.c:1629 3 locks held by syz.4.776/9617: #0: ffff888033a715f8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x267/0x390 fs/file.c:1192 #1: ffff888034af6420 (sb_writers#3){.+.+}-{0:0}, at: do_writev+0x133/0x340 fs/read_write.c:1096 #2: ffffffff8e5bda88 (nfsd_mutex){+.+.}-{4:4}, at: expkey_flush+0x18/0x90 fs/nfsd/export.c:252 2 locks held by syz.6.832/9924: #0: ffff88803bbec0e0 (&type->s_umount_key#49){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff88803bbec0e0 (&type->s_umount_key#49){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88803bbec0e0 (&type->s_umount_key#49){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:505 #1: ffffffff8e5bda88 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596 1 lock held by syz.6.832/9925: #0: ffff88803bbec0e0 (&type->s_umount_key#49){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff88803bbec0e0 (&type->s_umount_key#49){+.+.}-{4:4}, at: super_lock+0x176/0x3f0 fs/super.c:120 2 locks held by syz.7.1014/10773: #0: ffffffff8ff79070 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e5bda88 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x694/0xbe0 fs/nfsd/nfsctl.c:1629 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Tainted: G U 6.14.0-rc2-syzkaller-00034-gfebbc555cf0f #0 Tainted: [U]=USER Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline] watchdog+0xf62/0x12b0 kernel/hung_task.c:399 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 2959 Comm: kworker/u8:6 Tainted: G U 6.14.0-rc2-syzkaller-00034-gfebbc555cf0f #0 Tainted: [U]=USER Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Workqueue: bat_events batadv_nc_worker RIP: 0010:lockdep_softirqs_on+0x17a/0x340 kernel/locking/lockdep.c:4545 Code: ea 03 65 ff 05 3f 2d 6c 7e 0f b6 04 02 84 c0 74 08 3c 03 0f 8e b7 01 00 00 48 8d bb b0 0a 00 00 48 b8 00 00 00 00 00 fc ff df 85 d0 0a 00 00 01 00 00 00 48 89 fa 48 c1 ea 03 80 3c 02 00 0f RSP: 0018:ffffc9000c1c7a80 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: ffff888030629e00 RCX: 0000000000000000 RDX: 1ffff110060c551a RSI: ffffffff8b6ce880 RDI: ffff88803062a8b0 RBP: ffff888030629e00 R08: 0000000000000000 R09: fffffbfff20bfce2 R10: ffffffff905fe717 R11: 0000000000000002 R12: ffffffff8b1564c6 R13: ffff888082c19100 R14: 0000000000000000 R15: ffff888146fbcc80 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f109d779178 CR3: 0000000030a60000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __local_bh_enable_ip+0xd7/0x120 kernel/softirq.c:377 spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_nc_purge_paths+0x1c6/0x390 net/batman-adv/network-coding.c:471 batadv_nc_worker+0x94a/0x1060 net/batman-adv/network-coding.c:722 process_one_work+0x958/0x1b30 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3317 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244