INFO: task syz.4.1859:13288 blocked for more than 143 seconds. Tainted: G U 6.14.0-rc2-syzkaller-00039-g09fbf3d50205 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.1859 state:D stack:27088 pid:13288 tgid:13284 ppid:11437 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: 0033:0x7f210518cde9 RSP: 002b:00007f2102fd5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 00007f21053a6080 RCX: 00007f210518cde9 RDX: 000000000000000a RSI: 0000400000000200 RDI: 0000000000000004 RBP: 00007f210520e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f21053a6080 R15: 00007ffca0199118 Showing all locks held in the system: 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 2 locks held by kworker/u8:13/7601: #0: ffff88801ef03148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x12cd/0x1b30 kernel/workqueue.c:3211 #1: ffffc9000b677d18 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x8bb/0x1b30 kernel/workqueue.c:3212 5 locks held by kworker/u8:27/7617: #0: ffff88801bef5948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12cd/0x1b30 kernel/workqueue.c:3211 #1: ffffc9000b5b7d18 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8bb/0x1b30 kernel/workqueue.c:3212 #2: ffffffff8fec2e90 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xca/0xbf0 net/core/net_namespace.c:606 #3: ffffffff8fed8e68 (rtnl_mutex){+.+.}-{4:4}, at: cleanup_net+0x512/0xbf0 net/core/net_namespace.c:642 #4: ffffffff8e1c75b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x282/0x3b0 kernel/rcu/tree_exp.h:302 2 locks held by syz.2.1779/12955: #0: ffffffff8ff79370 (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.4.1859/13288: #0: ffff88807b6349b8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x267/0x390 fs/file.c:1192 #1: ffff88803b7ca420 (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.3.1927/13654: #0: ffff88807e4400e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff88807e4400e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88807e4400e0 (&type->s_umount_key#51){+.+.}-{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 2 locks held by syz.5.1989/14076: #0: ffffffff8ff79370 (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 2 locks held by getty/14109: #0: ffff8880318ef0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000348b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211 2 locks held by syz.8.2155/15199: #0: ffffffff8ff79370 (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.7.2242/15608: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Tainted: G U 6.14.0-rc2-syzkaller-00039-g09fbf3d50205 #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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 64 Comm: kworker/u8:4 Tainted: G U 6.14.0-rc2-syzkaller-00039-g09fbf3d50205 #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:check_wait_context kernel/locking/lockdep.c:4868 [inline] RIP: 0010:__lock_acquire+0x53d/0x3c40 kernel/locking/lockdep.c:5178 Code: a4 d5 11 0b 00 00 eb 10 83 eb 01 49 83 ec 28 83 fb ff 0f 84 a2 0b 00 00 49 8d 4c 24 df 4c 89 e2 4c 89 e6 48 c1 ea 03 83 e6 07 <0f> b6 14 2a 40 38 f2 7f 08 84 d2 0f 85 19 23 00 00 0f b6 51 21 44 RSP: 0018:ffffc9000215f8f8 EFLAGS: 00000002 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffff88801cb04718 RDX: 1ffff110039608e7 RSI: 0000000000000001 RDI: ffff88801cb04761 RBP: dffffc0000000000 R08: 0000000000000002 R09: fffffbfff2dc4998 R10: ffffffff96e24cc7 R11: 0000000000000002 R12: ffff88801cb04739 R13: ffff88801cb03c00 R14: 0000000000000000 R15: ffff88801cb04740 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe36bf79178 CR3: 000000002a3b4000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0x16a/0x1060 net/batman-adv/network-coding.c:719 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