syzbot

INFO: task syz.2.548:9557 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.548       state:D stack:28072 pid:9557  tgid:9556  ppid:8214   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929
 __schedule_loop kernel/sched/core.c:7011 [inline]
 rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7307
 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline]
 __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
 __rt_mutex_slowlock_locked+0x1e04/0x25e0 kernel/locking/rtmutex.c:1760
 __rwbase_read_lock+0xbc/0x180 kernel/locking/rwbase_rt.c:114
 rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline]
 __down_read kernel/locking/rwsem.c:1466 [inline]
 down_read+0x127/0x1f0 kernel/locking/rwsem.c:1539
 __super_lock fs/super.c:59 [inline]
 super_lock+0x2a9/0x3b0 fs/super.c:121
 user_get_super+0xc8/0x120 fs/super.c:997
 quotactl_block fs/quota/quota.c:890 [inline]
 __do_sys_quotactl fs/quota/quota.c:955 [inline]
 __se_sys_quotactl+0x4da/0x950 fs/quota/quota.c:917
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3684c7efc9
RSP: 002b:00007f3682ede038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f3684ed5fa0 RCX: 00007f3684c7efc9
RDX: 0000000000000000 RSI: 0000200000000580 RDI: ffffffff80000500
RBP: 00007f3684d01f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000200000000680 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3684ed6038 R14: 00007f3684ed5fa0 R15: 00007ffed8f33f18
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/38:
 #0: ffffffff8d7aa4c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8d7aa4c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #0: ffffffff8d7aa4c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:6/1129:
 #0: ffff88801a294938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
 #0: ffff88801a294938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
 #1: ffffc900048bfba0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
 #1: ffffc900048bfba0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
 #2: ffffffff8ea6a220 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x820 net/core/net_namespace.c:669
 #3: ffffffff8ea77138 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xdc/0x890 net/core/dev.c:12837
1 lock held by dhcpcd/5463:
 #0: ffffffff8ea77138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #0: ffffffff8ea77138 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:978
2 locks held by getty/5559:
 #0: ffff88823bf2a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90003e7e2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1400 drivers/tty/n_tty.c:2222
4 locks held by syz-executor/5805:
3 locks held by kworker/u8:12/7408:
 #0: ffff88813fe29938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
 #0: ffff88813fe29938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
 #1: ffffc9000c82fba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
 #1: ffffc9000c82fba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
 #2: ffffffff8ea77138 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
1 lock held by syz.2.548/9557:
 #0: ffff88805ed040d0 (&type->s_umount_key#63){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
 #0: ffff88805ed040d0 (&type->s_umount_key#63){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
3 locks held by kworker/u8:13/9945:
 #0: ffff88802fd82938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
 #0: ffff88802fd82938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
 #1: ffffc9000497fba0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
 #1: ffffc9000497fba0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
 #2: ffffffff8ea77138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #2: ffffffff8ea77138 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x119/0x15a0 net/ipv6/addrconf.c:4194
7 locks held by syz-executor/10091:
 #0: ffff888034190480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3111 [inline]
 #0: ffff888034190480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682
 #1: ffff888054d32478 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343
 #2: ffff888144b723c8 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #2: ffff888144b723c8 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344
 #3: ffffffff8e307ed8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x12c/0x6f0 drivers/net/netdevsim/bus.c:184
 #4: ffff8880305590d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
 #4: ffff8880305590d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006
 #5: ffff88803055c300 (&devlink->lock_key#35){+.+.}-{4:4}, at: nsim_drv_probe+0xc2/0xba0 drivers/net/netdevsim/dev.c:1582
 #6: ffffffff8ea77138 (rtnl_mutex){+.+.}-{4:4}, at: nsim_init_netdevsim drivers/net/netdevsim/netdev.c:1047 [inline]
 #6: ffffffff8ea77138 (rtnl_mutex){+.+.}-{4:4}, at: nsim_create+0x800/0x1060 drivers/net/netdevsim/netdev.c:1141
4 locks held by syz-executor/10094:
 #0: ffff888034190480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3111 [inline]
 #0: ffff888034190480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682
 #1: ffff888047c1d478 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343
 #2: ffff888144b723c8 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #2: ffff888144b723c8 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344
 #3: ffffffff8e307ed8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x12c/0x6f0 drivers/net/netdevsim/bus.c:184
2 locks held by syz-executor/10118:
 #0: ffffffff8e201220 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e201220 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #0: ffffffff8e201220 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
 #1: ffffffff8ea77138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #1: ffffffff8ea77138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 #1: ffffffff8ea77138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064
2 locks held by syz-executor/10184:
 #0: ffffffff8ea6a220 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0 net/core/net_namespace.c:576
 #1: ffffffff8ea77138 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2ab/0x800 net/ipv4/ip_tunnel.c:1146
2 locks held by syz-executor/10190:
 #0: ffffffff8ea6a220 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0 net/core/net_namespace.c:576
 #1: ffffffff8ea77138 (rtnl_mutex){+.+.}-{4:4}, at: register_nexthop_notifier+0x80/0x210 net/ipv4/nexthop.c:3971

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
 <TASK>
 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:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline]
 watchdog+0xf60/0xfa0 kernel/hung_task.c:495
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5805 Comm: syz-executor Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:97 [inline]
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:115 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:140 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:172 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:191 [inline]
RIP: 0010:kasan_check_range+0x89/0x2c0 mm/kasan/generic.c:200
Code: ff df 4f 8d 1c 17 49 ff c8 4d 89 c1 49 c1 e9 03 48 bb 01 00 00 00 00 fc ff df 4d 8d 34 19 4d 89 f4 4d 29 dc 49 83 fc 10 7f 29 <4d> 85 e4 0f 84 41 01 00 00 4c 89 cb 48 f7 d3 4c 01 fb 41 80 3b 00
RSP: 0018:ffffc90004abf6c0 EFLAGS: 00000283
RAX: ffffffff840b5a01 RBX: dffffc0000000001 RCX: ffffffff840b5b05
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffea0000deceb4
RBP: 0000000000000003 R08: ffffea0000deceb7 R09: 1ffffd40001bd9d6
R10: dffffc0000000000 R11: fffff940001bd9d6 R12: 0000000000000001
R13: 0000000000000001 R14: fffff940001bd9d7 R15: 1ffffd40001bd9d6
FS:  00005555829b9500(0000) GS:ffff888126cc2000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2d3669fe7a CR3: 000000004c21a000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_dec_and_test include/linux/atomic/atomic-instrumented.h:1383 [inline]
 page_ref_dec_and_test include/linux/page_ref.h:205 [inline]
 put_page_testzero include/linux/mm.h:1102 [inline]
 folio_put_testzero include/linux/mm.h:1107 [inline]
 folio_put include/linux/mm.h:1424 [inline]
 f2fs_folio_put+0x105/0x1a0 fs/f2fs/f2fs.h:2983
 __get_node_folio+0xf3a/0x14d0 fs/f2fs/node.c:1590
 f2fs_update_inode_page+0x82/0x190 fs/f2fs/inode.c:766
 f2fs_sync_inode_meta fs/f2fs/checkpoint.c:1156 [inline]
 block_operations fs/f2fs/checkpoint.c:1263 [inline]
 f2fs_write_checkpoint+0xb4d/0x2440 fs/f2fs/checkpoint.c:1678
 kill_f2fs_super+0x2cc/0x6d0 fs/f2fs/super.c:5448
 deactivate_locked_super+0xbc/0x130 fs/super.c:473
 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1327
 task_work_run+0x1d4/0x260 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop+0xe9/0x130 kernel/entry/common.c:43
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
 do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f72d37b02f7
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:00007ffd0acb3e08 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f72d3831d7d RCX: 00007f72d37b02f7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd0acb3ec0
RBP: 00007ffd0acb3ec0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd0acb4f50
R13: 00007f72d3831d7d R14: 000000000001d916 R15: 00007ffd0acb4f90
 </TASK>