INFO: task syz.5.258:8749 blocked for more than 143 seconds. Not tainted 6.15.0-rc3-syzkaller-00094-g02ddfb981de8 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.258 state:D stack:25048 pid:8749 tgid:8747 ppid:8076 task_flags:0x440140 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x168f/0x4c70 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x165/0x360 kernel/sched/core.c:6860 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917 rwsem_down_read_slowpath+0x552/0x880 kernel/locking/rwsem.c:1084 __down_read_common kernel/locking/rwsem.c:1248 [inline] __down_read kernel/locking/rwsem.c:1261 [inline] down_read+0x98/0x2e0 kernel/locking/rwsem.c:1526 filemap_invalidate_lock_shared include/linux/fs.h:922 [inline] page_cache_ra_order+0x445/0xc70 mm/readahead.c:491 filemap_get_pages+0x43c/0x1eb0 mm/filemap.c:2591 filemap_splice_read+0x4fc/0xbc0 mm/filemap.c:2981 do_splice_read fs/splice.c:979 [inline] splice_direct_to_actor+0x4a6/0xcc0 fs/splice.c:1083 do_splice_direct_actor fs/splice.c:1201 [inline] do_splice_direct+0x181/0x270 fs/splice.c:1227 do_sendfile+0x4da/0x7d0 fs/read_write.c:1368 __do_sys_sendfile64 fs/read_write.c:1429 [inline] __se_sys_sendfile64+0x13e/0x190 fs/read_write.c:1415 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5d6c38e969 RSP: 002b:00007f5d6d269038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f5d6c5b5fa0 RCX: 00007f5d6c38e969 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 0000000000000008 RBP: 00007f5d6c410ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000fffe82 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f5d6c5b5fa0 R15: 00007fff2011cee8 INFO: task syz.1.262:8795 blocked for more than 144 seconds. Not tainted 6.15.0-rc3-syzkaller-00094-g02ddfb981de8 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.262 state:D stack:25272 pid:8795 tgid:8794 ppid:8399 task_flags:0x440140 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x168f/0x4c70 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x165/0x360 kernel/sched/core.c:6860 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917 rwsem_down_read_slowpath+0x552/0x880 kernel/locking/rwsem.c:1084 __down_read_common kernel/locking/rwsem.c:1248 [inline] __down_read kernel/locking/rwsem.c:1261 [inline] down_read+0x98/0x2e0 kernel/locking/rwsem.c:1526 filemap_invalidate_lock_shared include/linux/fs.h:922 [inline] page_cache_ra_order+0x445/0xc70 mm/readahead.c:491 filemap_get_pages+0x43c/0x1eb0 mm/filemap.c:2591 filemap_splice_read+0x4fc/0xbc0 mm/filemap.c:2981 do_splice_read fs/splice.c:979 [inline] splice_direct_to_actor+0x4a6/0xcc0 fs/splice.c:1083 do_splice_direct_actor fs/splice.c:1201 [inline] do_splice_direct+0x181/0x270 fs/splice.c:1227 do_sendfile+0x4da/0x7d0 fs/read_write.c:1368 __do_sys_sendfile64 fs/read_write.c:1429 [inline] __se_sys_sendfile64+0x13e/0x190 fs/read_write.c:1415 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f03d3b8e969 RSP: 002b:00007f03d497c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f03d3db5fa0 RCX: 00007f03d3b8e969 RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000005 RBP: 00007f03d3c10ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000fffe82 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f03d3db5fa0 R15: 00007fffbee9d638 Showing all locks held in the system: 3 locks held by kworker/u8:0/12: 1 lock held by khungtaskd/31: #0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764 4 locks held by kworker/u8:3/53: #0: ffff88801aef3948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801aef3948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc90000be7c60 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000be7c60 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 #2: ffffffff8f2d4050 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x145/0xbd0 net/core/net_namespace.c:608 #3: ffffffff8f2e0b88 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xdc/0x890 net/core/dev.c:12524 3 locks held by kworker/u8:4/67: #0: ffff88801a089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801a089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc9000155fc60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000155fc60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 #2: ffffffff8f2e0b88 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 3 locks held by kworker/u8:7/2944: #0: ffff8880300bd148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff8880300bd148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc9000bb3fc60 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000bb3fc60 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 #2: ffffffff8f2e0b88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f2e0b88 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x112/0x14b0 net/ipv6/addrconf.c:4195 4 locks held by udevd/5189: #0: ffff88805061b0a0 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe10 fs/seq_file.c:182 #1: ffff8880250a9888 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x55/0x3c0 fs/kernfs/file.c:154 #2: ffff8880465ea788 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0x75/0x3c0 fs/kernfs/file.c:155 #3: ffff88807ae9d0e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #3: ffff88807ae9d0e8 (&dev->mutex){....}-{4:4}, at: uevent_show+0x174/0x330 drivers/base/core.c:2730 2 locks held by dhcpcd/5483: #0: ffff88806d2a06d0 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: netlink_dump+0xcd/0xe70 net/netlink/af_netlink.c:2255 #1: ffffffff8f2e0b88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f2e0b88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200 net/core/rtnetlink.c:6823 2 locks held by getty/5570: #0: ffff88803490a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900033332f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 3 locks held by syz.8.190/7824: 1 lock held by syz.5.258/8749: #0: ffff88802293a040 (mapping.invalidate_lock#2){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:922 [inline] #0: ffff88802293a040 (mapping.invalidate_lock#2){++++}-{4:4}, at: page_cache_ra_order+0x445/0xc70 mm/readahead.c:491 1 lock held by syz.1.262/8795: #0: ffff88802293a040 (mapping.invalidate_lock#2){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:922 [inline] #0: ffff88802293a040 (mapping.invalidate_lock#2){++++}-{4:4}, at: page_cache_ra_order+0x445/0xc70 mm/readahead.c:491 1 lock held by syz-executor/9681: #0: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #0: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b7/0x730 kernel/rcu/tree_exp.h:998 1 lock held by syz.8.360/10209: #0: ffff88802293a040 (mapping.invalidate_lock#2){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:922 [inline] #0: ffff88802293a040 (mapping.invalidate_lock#2){++++}-{4:4}, at: page_cache_ra_order+0x445/0xc70 mm/readahead.c:491 1 lock held by syz.0.370/10318: #0: ffff88802293a040 (mapping.invalidate_lock#2){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:922 [inline] #0: ffff88802293a040 (mapping.invalidate_lock#2){++++}-{4:4}, at: page_cache_ra_order+0x445/0xc70 mm/readahead.c:491 1 lock held by syz-executor/10588: #0: ffffffff8f2e0b88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f2e0b88 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x5b7/0xd20 net/ipv6/addrconf.c:5028 7 locks held by syz-executor/10606: #0: ffff888034b78420 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3041 [inline] #0: ffff888034b78420 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x211/0xa90 fs/read_write.c:680 #1: ffff888033ea4088 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e0/0x4f0 fs/kernfs/file.c:325 #2: ffff888143b1a3c8 (kn->active#50){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x203/0x4f0 fs/kernfs/file.c:326 #3: ffffffff8eb81ca8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x12c/0x6f0 drivers/net/netdevsim/bus.c:166 #4: ffff88807ae9d0e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #4: ffff88807ae9d0e8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1005 #5: ffff88807ae9e250 (&devlink->lock_key#28){+.+.}-{4:4}, at: nsim_drv_probe+0xc1/0xb70 drivers/net/netdevsim/dev.c:1537 #6: ffffffff8f2e0b88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #6: ffffffff8f2e0b88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2089 1 lock held by syz.1.391/10616: #0: ffff88802293a040 (mapping.invalidate_lock#2){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:922 [inline] #0: ffff88802293a040 (mapping.invalidate_lock#2){++++}-{4:4}, at: page_cache_ra_order+0x445/0xc70 mm/readahead.c:491 2 locks held by syz-executor/10835: #0: ffffffff8ea7b8e0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8ea7b8e0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8ea7b8e0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8f2e0b88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f2e0b88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8f2e0b88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4064 2 locks held by syz-executor/10871: #0: ffffffff8f7f9a70 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8f7f9a70 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8f7f9a70 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8f2e0b88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f2e0b88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8f2e0b88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4064 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc3-syzkaller-00094-g02ddfb981de8 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 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:274 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:437 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 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: 9681 Comm: syz-executor Not tainted 6.15.0-rc3-syzkaller-00094-g02ddfb981de8 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:409 Code: e8 0e a3 89 fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 9f 72 e9 fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 cc cc cc cc cc 44 89 f9 80 e1 07 RSP: 0018:ffffc9000511f538 EFLAGS: 00000006 RAX: 1ffffffff3362905 RBX: 00000000000003f9 RCX: 0000000000000000 RDX: 00000000000003f9 RSI: 0000000000000000 RDI: 0000000000000020 RBP: ffffc9000511f710 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: ffffffff85361930 R12: dffffc0000000000 R13: dffffc0000000000 R14: ffffffff99b14980 R15: 0000000000000000 FS: 0000555573145500(0000) GS:ffff888126203000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2f3e7ff8 CR3: 0000000060ae0000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: serial_port_in include/linux/serial_core.h:791 [inline] serial8250_console_write+0x581/0x1ba0 drivers/tty/serial/8250/8250_port.c:3420 console_emit_next_record kernel/printk/printk.c:3138 [inline] console_flush_all+0x725/0xc40 kernel/printk/printk.c:3226 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline] console_unlock+0xc4/0x270 kernel/printk/printk.c:3325 vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450 _printk+0xcf/0x120 kernel/printk/printk.c:2475 _btrfs_printk+0x562/0x5b0 fs/btrfs/messages.c:248 btrfs_put_super+0x69/0x80 fs/btrfs/super.c:73 generic_shutdown_super+0x132/0x2c0 fs/super.c:642 kill_anon_super+0x3b/0x70 fs/super.c:1237 btrfs_kill_super+0x41/0x50 fs/btrfs/super.c:2099 deactivate_locked_super+0xb9/0x130 fs/super.c:473 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1435 task_work_run+0x1d1/0x260 kernel/task_work.c:227 resume_user_mode_work+0x5e/0x80 include/linux/resume_user_mode.h:50 exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x9a/0x120 kernel/entry/common.c:218 do_syscall_64+0x103/0x210 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f009718fc97 Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8 RSP: 002b:00007fff0b9efa48 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f009721089d RCX: 00007f009718fc97 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff0b9efb00 RBP: 00007fff0b9efb00 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fff0b9f0b90 R13: 00007f009721089d R14: 000000000006efb5 R15: 00007fff0b9f0bd0