INFO: task syz.0.82:5331 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.82 state:D stack:22304 pid:5331 ppid:5190 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 io_schedule+0x7c/0xd0 kernel/sched/core.c:8797 __lock_metapage fs/jfs/jfs_metapage.c:50 [inline] lock_metapage+0x1e8/0x310 fs/jfs/jfs_metapage.c:64 __get_metapage+0x4c6/0xfa0 fs/jfs/jfs_metapage.c:639 xtSplitPage+0x238/0x1c10 fs/jfs/jfs_xtree.c:974 xtSplitUp+0x293/0x1c20 fs/jfs/jfs_xtree.c:771 xtInsert+0x455/0xbb0 fs/jfs/jfs_xtree.c:593 extAlloc+0x9f6/0xf30 fs/jfs/jfs_extent.c:145 jfs_get_block+0x343/0xab0 fs/jfs/inode.c:254 __block_write_begin_int+0x54b/0x1a70 fs/buffer.c:1991 __block_write_begin fs/buffer.c:2041 [inline] block_write_begin+0x96/0x1e0 fs/buffer.c:2102 jfs_write_begin+0x31/0x70 fs/jfs/inode.c:310 generic_perform_write+0x2f7/0x5a0 mm/filemap.c:3862 __generic_file_write_iter+0x148/0x2a0 mm/filemap.c:3960 generic_file_write_iter+0xab/0x2e0 mm/filemap.c:3989 __kernel_write_iter+0x26d/0x630 fs/read_write.c:517 dump_emit_page fs/coredump.c:950 [inline] dump_user_range+0x3ea/0x7f0 fs/coredump.c:977 elf_core_dump+0x2f77/0x3490 fs/binfmt_elf.c:2354 do_coredump+0x15ff/0x22b0 fs/coredump.c:824 get_signal+0x10aa/0x1350 kernel/signal.c:2857 arch_do_signal_or_restart+0xb7/0x1240 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:316 exc_page_fault+0x88/0x100 arch/x86/mm/fault.c:1490 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x7f61fd18f751 RSP: 002b:00000000fffffe60 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f61fd3e5fa0 RCX: 00007f61fd18f749 RDX: 0000000000000000 RSI: 00000000fffffe60 RDI: 0000000000040000 RBP: 00007f61fd213f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f61fd3e5fa0 R14: 00007f61fd3e5fa0 R15: 0000000000000006 Showing all locks held in the system: 4 locks held by kworker/u4:0/9: #0: ffff888017616938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc900000e7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8db2e6d0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x132/0xb80 net/core/net_namespace.c:594 #3: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: caif_exit_net+0x66/0x490 net/caif/caif_dev.c:527 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8c92bab0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8c92c2d0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 3 locks held by kworker/1:0/22: #0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc900001c7d00 (fqdir_free_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8c930cc0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x48/0x600 kernel/rcu/tree.c:4023 1 lock held by khungtaskd/27: #0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 1 lock held by dhcpcd/3932: #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0x288/0x1af0 net/ipv4/devinet.c:1080 2 locks held by getty/4023: #0: ffff88807f6d0098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198 3 locks held by kworker/1:3/4287: #0: ffff88802f15b138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90004197d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x14d0 net/ipv6/addrconf.c:4131 2 locks held by kworker/1:6/4469: #0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90003577d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 3 locks held by kworker/1:11/4877: 4 locks held by syz.0.82/5331: #0: ffff888059ee8460 (sb_writers#13){.+.+}-{0:0}, at: do_coredump+0x15de/0x22b0 fs/coredump.c:823 #1: ffff8880688b2a80 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #1: ffff8880688b2a80 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: generic_file_write_iter+0x7f/0x2e0 mm/filemap.c:3986 #2: ffff8880688b2638 (&jfs_ip->rdwrlock#2){+.+.}-{3:3}, at: jfs_get_block+0x13e/0xab0 fs/jfs/inode.c:219 #3: ffff8880688b26c8 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: extAlloc+0x10b/0xf30 fs/jfs/jfs_extent.c:81 2 locks held by udevd/5761: 4 locks held by syz.9.164/6405: #0: ffff8880591ce460 (sb_writers#13){.+.+}-{0:0}, at: do_coredump+0x15de/0x22b0 fs/coredump.c:823 #1: ffff8880548de200 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #1: ffff8880548de200 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: generic_file_write_iter+0x7f/0x2e0 mm/filemap.c:3986 #2: ffff8880548dddb8 (&jfs_ip->rdwrlock#2){+.+.}-{3:3}, at: jfs_get_block+0x13e/0xab0 fs/jfs/inode.c:219 #3: ffff8880548dde48 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: extAlloc+0x10b/0xf30 fs/jfs/jfs_extent.c:81 1 lock held by syz-executor/6433: #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147 2 locks held by syz-executor/6511: #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147 #1: ffffffff8c930df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] #1: ffffffff8c930df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x455/0x830 kernel/rcu/tree_exp.h:962 1 lock held by syz-executor/6550: #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147 2 locks held by syz-executor/6642: #0: ffffffff8db2e6d0 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x32e/0x5b0 net/core/net_namespace.c:504 #1: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: register_nexthop_notifier+0x7d/0x210 net/ipv4/nexthop.c:3619 2 locks held by syz.0.240/6662: 1 lock held by syz.0.241/6663: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xeee/0xf30 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 2905 Comm: kworker/u4:5 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: bat_events batadv_nc_worker RIP: 0010:__lock_acquire+0xed/0x7c50 kernel/locking/lockdep.c:4919 Code: 84 c0 0f 85 53 65 00 00 83 3d b2 3a 9c 0c 00 0f 84 c0 27 00 00 83 3d c1 85 1c 0b 00 74 29 48 89 d8 48 c1 e8 03 42 80 3c 00 00 <74> 12 48 89 df e8 c9 08 6e 00 49 b8 00 00 00 00 00 fc ff df 48 81 RSP: 0000:ffffc9000c3f7780 EFLAGS: 00000046 RAX: 1ffff1100f4e1903 RBX: ffff88807a70c818 RCX: 1ffff9200187ef14 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88807a70c818 RBP: ffffc9000c3f79d0 R08: dffffc0000000000 R09: 0000000000000000 R10: fffffbfff1bfe1c6 R11: 1ffffffff1bfe1c5 R12: ffff88802e790000 R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9567d06000 CR3: 000000007ebe8000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x32/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] batadv_nc_purge_paths+0xe7/0x3b0 net/batman-adv/network-coding.c:442 batadv_nc_worker+0x365/0x600 net/batman-adv/network-coding.c:722 process_one_work+0x898/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295