INFO: task syz.3.329:8830 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.329 state:D stack:26800 pid:8830 tgid:8825 ppid:7897 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5533 [inline] __schedule+0x16d9/0x5700 kernel/sched/core.c:7284 __schedule_loop kernel/sched/core.c:7361 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7668 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1670 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1747 [inline] __rt_mutex_slowlock_locked+0x1f88/0x25b0 kernel/locking/rtmutex.c:1787 __rwbase_read_lock+0xc3/0x190 kernel/locking/rwbase_rt.c:114 rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline] __down_read kernel/locking/rwsem.c:1502 [inline] down_read+0x132/0x200 kernel/locking/rwsem.c:1576 __super_lock fs/super.c:62 [inline] super_lock+0x2d6/0x3d0 fs/super.c:124 __iterate_supers+0x26b/0x420 fs/super.c:979 quota_sync_all fs/quota/quota.c:69 [inline] __do_sys_quotactl fs/quota/quota.c:938 [inline] __se_sys_quotactl+0x3a0/0x9f0 fs/quota/quota.c:917 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9d783ae159 RSP: 002b:00007f9d765e5028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007f9d78636090 RCX: 00007f9d783ae159 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000101 RBP: 00007f9d7844506b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9d78636128 R14: 00007f9d78636090 R15: 00007fff67b046a8 INFO: task syz.3.329:8833 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.329 state:D stack:27048 pid:8833 tgid:8825 ppid:7897 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5533 [inline] __schedule+0x16d9/0x5700 kernel/sched/core.c:7284 __schedule_loop kernel/sched/core.c:7361 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7668 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1670 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1747 [inline] __rt_mutex_slowlock_locked+0x1f88/0x25b0 kernel/locking/rtmutex.c:1787 __rwbase_read_lock+0xc3/0x190 kernel/locking/rwbase_rt.c:114 rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline] __down_read kernel/locking/rwsem.c:1502 [inline] down_read+0x132/0x200 kernel/locking/rwsem.c:1576 __super_lock fs/super.c:62 [inline] super_lock+0x2d6/0x3d0 fs/super.c:124 __iterate_supers+0x26b/0x420 fs/super.c:979 quota_sync_all fs/quota/quota.c:69 [inline] __do_sys_quotactl fs/quota/quota.c:938 [inline] __se_sys_quotactl+0x3a0/0x9f0 fs/quota/quota.c:917 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9d783ae159 RSP: 002b:00007f9d76582028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007f9d78636360 RCX: 00007f9d783ae159 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000101 RBP: 00007f9d7844506b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9d786363f8 R14: 00007f9d78636360 R15: 00007fff67b046a8 Showing all locks held in the system: locks held by kworker/u8:0/12: 3, on CPU#0: #0: ffff888032b39938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff888032b39938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff888032b39938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #0: ffff888032b39938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #1: ffffc90000117c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc90000117c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc90000117c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #1: ffffc90000117c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #2: ffffffff8f5d58b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:134 [inline] #2: ffffffff8f5d58b8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x123/0x16e0 net/ipv6/addrconf.c:4230 locks held by pr/ttyS0/17: 3, last CPU#1: #0: ffffffff8e09d7d8 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:314 [inline] #0: ffffffff8e09d7d8 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:439 [inline] #0: ffffffff8e09d7d8 (console_srcu){....}-{0:0}, at: console_srcu_read_lock+0x30/0x60 kernel/printk/printk.c:291 #1: ffffffff99eaa3f8 (&port_lock_key){+.+.}-{3:3}, at: nbcon_emit_one kernel/printk/nbcon.c:1137 [inline] #1: ffffffff99eaa3f8 (&port_lock_key){+.+.}-{3:3}, at: nbcon_kthread_func+0x64c/0x880 kernel/printk/nbcon.c:1271 #2: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #2: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #2: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #2: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e2/0x400 kernel/locking/spinlock_rt.c:57 locks held by khungtaskd/37: 1, last CPU#0: #0: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871 locks held by kworker/u8:13/1366: 3, on CPU#0: #0: ffff88801aeb0938 ((wq_completion)netns){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff88801aeb0938 ((wq_completion)netns){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff88801aeb0938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #0: ffff88801aeb0938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #1: ffffc90006e5fc40 (net_cleanup_work){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc90006e5fc40 (net_cleanup_work){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc90006e5fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #1: ffffc90006e5fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #2: ffffffff8f5c7060 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810 net/core/net_namespace.c:677 locks held by kworker/0:3/4914: 3, on CPU#0: #0: ffff88813ff27938 ((wq_completion)events){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff88813ff27938 ((wq_completion)events){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff88813ff27938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #0: ffff88813ff27938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #1: ffffc90005a17c40 (deferred_process_work){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc90005a17c40 (deferred_process_work){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc90005a17c40 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #1: ffffc90005a17c40 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #2: ffffffff8f5d58b8 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 locks held by jbd2/sda1-8/4915: 7, last CPU#0: #0: ffff88803391e2c0 (&ret->b_state_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #0: ffff88803391e2c0 (&ret->b_state_lock){+.+.}-{3:3}, at: jbd2_journal_commit_transaction+0x3a56/0x5ba0 fs/jbd2/commit.c:960 #1: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #1: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e2/0x400 kernel/locking/spinlock_rt.c:57 #2: ffff88802a3de920 (&journal->j_list_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #2: ffff88802a3de920 (&journal->j_list_lock){+.+.}-{3:3}, at: jbd2_journal_commit_transaction+0x3bfd/0x5ba0 fs/jbd2/commit.c:990 #3: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #3: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #3: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #3: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e2/0x400 kernel/locking/spinlock_rt.c:57 #4: ffff88802bf7e118 (&wb->list_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #4: ffff88802bf7e118 (&wb->list_lock){+.+.}-{3:3}, at: locked_inode_to_wb_and_lock_list+0x208/0x310 fs/fs-writeback.c:351 #5: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #5: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #5: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #5: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e2/0x400 kernel/locking/spinlock_rt.c:57 #6: ffff8880271a3068 (&sb->s_type->i_lock_key#5){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #6: ffff8880271a3068 (&sb->s_type->i_lock_key#5){+.+.}-{3:3}, at: __mark_inode_dirty+0x705/0x13b0 fs/fs-writeback.c:2788 locks held by getty/5342: 2, on CPU#0: #0: ffff8880369b20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900044cb2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211 locks held by syz-executor/5574: 4, last CPU#0: #0: ffff888040a69db8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:600 [inline] #0: ffff888040a69db8 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x1a4/0x9f0 mm/mmap.c:1299 #1: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: folio_lruvec_lock_irqsave+0x24/0x540 mm/memcontrol.c:1506 #2: ffff88801aed6070 (&lruvec->lru_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #2: ffff88801aed6070 (&lruvec->lru_lock){+.+.}-{3:3}, at: folio_lruvec_lock_irqsave+0x293/0x540 mm/memcontrol.c:1509 #3: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #3: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #3: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #3: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e2/0x400 kernel/locking/spinlock_rt.c:57 locks held by kworker/0:6/5605: 2, last CPU#0: #0: ffff88813ff27938 ((wq_completion)events){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff88813ff27938 ((wq_completion)events){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff88813ff27938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #0: ffff88813ff27938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #1: ffffc90005b27c40 ((work_completion)(&(&devlink->rwork)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc90005b27c40 ((work_completion)(&(&devlink->rwork)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc90005b27c40 ((work_completion)(&(&devlink->rwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #1: ffffc90005b27c40 ((work_completion)(&(&devlink->rwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 locks held by syz-executor/7543: 3, last CPU#1: #0: ffff88801166c0e0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff88801166c0e0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline] #0: ffff88801166c0e0 (&type->s_umount_key#72){++++}-{4:4}, at: deactivate_super+0xac/0xe0 fs/super.c:613 #1: ffff88802ad10350 (&sbi->cp_global_sem_key){+.+.}-{4:4}, at: f2fs_down_write fs/f2fs/f2fs.h:2469 [inline] #1: ffff88802ad10350 (&sbi->cp_global_sem_key){+.+.}-{4:4}, at: f2fs_down_write_trace+0x34/0x1f0 fs/f2fs/checkpoint.c:181 #2: ffff88802ad103e8 (&sbi->cp_rwsem){++++}-{4:4}, at: f2fs_down_write fs/f2fs/f2fs.h:2469 [inline] #2: ffff88802ad103e8 (&sbi->cp_rwsem){++++}-{4:4}, at: f2fs_lock_all fs/f2fs/checkpoint.c:223 [inline] #2: ffff88802ad103e8 (&sbi->cp_rwsem){++++}-{4:4}, at: block_operations fs/f2fs/checkpoint.c:1530 [inline] #2: ffff88802ad103e8 (&sbi->cp_rwsem){++++}-{4:4}, at: f2fs_write_checkpoint+0x677/0x2710 fs/f2fs/checkpoint.c:1987 locks held by syz.3.329/8830: 1, on CPU#0: #0: ffff88801166c0e0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:62 [inline] #0: ffff88801166c0e0 (&type->s_umount_key#72){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:124 locks held by syz.3.329/8833: 1, on CPU#1: #0: ffff88801166c0e0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:62 [inline] #0: ffff88801166c0e0 (&type->s_umount_key#72){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:124 locks held by syz-executor/9703: 1, on CPU#0: #0: ffffffff8f5d58b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:134 [inline] #0: ffffffff8f5d58b8 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x667/0xe00 net/ipv6/addrconf.c:5063 locks held by syz-executor/9821: 4, on CPU#0: #0: ffff88803514e510 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline] #0: ffff88803514e510 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683 #1: ffff8880250bb078 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d9/0x540 fs/kernfs/file.c:336 #2: ffff88802933db48 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline] #2: ffff88802933db48 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22c/0x540 fs/kernfs/file.c:337 #3: ffffffff8ee45d38 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x13c/0x6d0 drivers/net/netdevsim/bus.c:184 locks held by syz-executor/9831: 8, last CPU#0: #0: ffff88803514e510 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline] #0: ffff88803514e510 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683 #1: ffff88805b95f478 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d9/0x540 fs/kernfs/file.c:336 #2: ffff88802933da58 (kn->active#51){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline] #2: ffff88802933da58 (kn->active#51){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22c/0x540 fs/kernfs/file.c:337 #3: ffffffff8ee45d38 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd6/0x370 drivers/net/netdevsim/bus.c:234 #4: ffff88803c86d160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #4: ffff88803c86d160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1171 [inline] #4: ffff88803c86d160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb9/0x880 drivers/base/dd.c:1369 #5: ffff8880341e6310 (&devlink->lock_key#4){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1724 #6: ffff888067cb4890 (&sb->s_type->i_mutex_key#8/2){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1069 [inline] #6: ffff888067cb4890 (&sb->s_type->i_mutex_key#8/2){+.+.}-{4:4}, at: __simple_recursive_removal+0x19a/0x520 fs/libfs.c:619 #7: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #7: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #7: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: fast_dput+0x1e/0x690 fs/dcache.c:938 locks held by syz-executor/9879: 4, last CPU#0: #0: ffffffff8ed35128 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff8ed35128 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8ed35128 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:595 #1: ffffffff8f5d58b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f5d58b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:366 [inline] #1: ffffffff8f5d58b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc10/0x1c30 net/core/rtnetlink.c:4219 #2: ffff88806c70a628 (&idev->mc_lock){+.+.}-{4:4}, at: __ipv6_dev_mc_inc+0x4e/0xaf0 net/ipv6/mcast.c:963 #3: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #3: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #3: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline] #3: ffffffff8e1c3cc0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495 locks held by syz-executor/9947: 2, on CPU#0: #0: ffffffff8ed35128 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff8ed35128 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8ed35128 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:595 #1: ffffffff8f5d58b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f5d58b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:366 [inline] #1: ffffffff8f5d58b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc10/0x1c30 net/core/rtnetlink.c:4219 locks held by dhcpcd-run-hook/10086: 1, last CPU#0: #0: ffff88803eeb21a8 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xa5/0xcb0 fs/seq_file.c:183 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123 nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66 trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x38b/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 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: 17 Comm: pr/ttyS0 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:409 Code: e8 1e 82 64 fc 44 89 f9 d3 e3 49 83 ee 80 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 cf 79 d0 fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 da 73 fa 05 cc 44 89 f9 80 e1 07 RSP: 0018:ffffc900001678b8 EFLAGS: 00000202 RAX: 1ffffffff33d5400 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000000 RBP: dffffc0000000000 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffffff856255c0 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff99eaa420 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125cc3000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f75e76c2eb8 CR3: 00000000413d4000 CR4: 00000000003526f0 Call Trace: serial_in drivers/tty/serial/8250/8250.h:128 [inline] serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline] wait_for_lsr+0x190/0x300 drivers/tty/serial/8250/8250_port.c:2013 serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3270 [inline] __serial8250_console_fifo_write+0xd0/0x3f0 drivers/tty/serial/8250/8250_port.c:3345 serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3378 [inline] __serial8250_console_write drivers/tty/serial/8250/8250_port.c:3429 [inline] serial8250_console_write+0xac5/0x1230 drivers/tty/serial/8250/8250_port.c:3493 nbcon_emit_next_record+0xef5/0x1a90 kernel/printk/nbcon.c:-1 nbcon_emit_one kernel/printk/nbcon.c:1157 [inline] nbcon_kthread_func+0x679/0x880 kernel/printk/nbcon.c:1271 kthread+0x38b/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245