INFO: task syz.2.179:7185 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.179 state:D stack:24536 pid:7185 tgid:7181 ppid:5797 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1480/0x50a0 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7241 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1dfe/0x25e0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xb5/0x160 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14f/0x750 kernel/locking/rwbase_rt.c:244 inode_lock include/linux/fs.h:1027 [inline] open_last_lookups fs/namei.c:4537 [inline] path_openat+0xb53/0x3df0 fs/namei.c:4784 do_filp_open+0x1fa/0x410 fs/namei.c:4814 do_sys_openat2+0x121/0x200 fs/open.c:1430 do_sys_open fs/open.c:1436 [inline] __do_sys_open fs/open.c:1444 [inline] __se_sys_open fs/open.c:1440 [inline] __x64_sys_open+0x11e/0x150 fs/open.c:1440 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fee5d7bf749 RSP: 002b:00007fee5ba26038 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007fee5da15fa0 RCX: 00007fee5d7bf749 RDX: 0000000000000000 RSI: 0000000000080242 RDI: 0000200000000040 RBP: 00007fee5d843f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fee5da16038 R14: 00007fee5da15fa0 R15: 00007ffc64b988a8 INFO: task syz.2.179:7191 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.179 state:D stack:25432 pid:7191 tgid:7181 ppid:5797 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1480/0x50a0 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7241 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1dfe/0x25e0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xb5/0x160 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14f/0x750 kernel/locking/rwbase_rt.c:244 inode_lock_nested include/linux/fs.h:1072 [inline] __start_dirop fs/namei.c:2864 [inline] start_dirop fs/namei.c:2875 [inline] filename_create+0x1fb/0x360 fs/namei.c:4879 do_mkdirat+0xca/0x4b0 fs/namei.c:5156 __do_sys_mkdirat fs/namei.c:5186 [inline] __se_sys_mkdirat fs/namei.c:5184 [inline] __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:5184 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fee5d7bde97 RSP: 002b:00007fee5ba04e68 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007fee5ba04ef0 RCX: 00007fee5d7bde97 RDX: 00000000000001ff RSI: 0000200000000080 RDI: 00000000ffffff9c RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000080 R13: 00007fee5ba04eb0 R14: 0000000000000000 R15: 0000000000000000 INFO: task syz.2.179:7192 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.179 state:D stack:25456 pid:7192 tgid:7181 ppid:5797 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1480/0x50a0 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 io_schedule+0x81/0xe0 kernel/sched/core.c:7789 folio_wait_bit_common+0x6b5/0xb90 mm/filemap.c:1323 folio_lock include/linux/pagemap.h:1159 [inline] release_metapage+0x103/0xab0 fs/jfs/jfs_metapage.c:870 discard_metapage fs/jfs/jfs_metapage.h:88 [inline] __get_metapage+0x9a3/0xde0 fs/jfs/jfs_metapage.c:753 dtSplitPage+0x7f8/0x3b20 fs/jfs/jfs_dtree.c:1471 dtSplitUp fs/jfs/jfs_dtree.c:1092 [inline] dtInsert+0x109b/0x5f40 fs/jfs/jfs_dtree.c:871 jfs_create+0x6c8/0xa80 fs/jfs/namei.c:137 lookup_open fs/namei.c:4440 [inline] open_last_lookups fs/namei.c:4540 [inline] path_openat+0x18d1/0x3df0 fs/namei.c:4784 do_filp_open+0x1fa/0x410 fs/namei.c:4814 do_sys_openat2+0x121/0x200 fs/open.c:1430 do_sys_open fs/open.c:1436 [inline] __do_sys_openat fs/open.c:1452 [inline] __se_sys_openat fs/open.c:1447 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1447 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fee5d7bf749 RSP: 002b:00007fee5b9e4038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fee5da16180 RCX: 00007fee5d7bf749 RDX: 0000000000000042 RSI: 0000200000000040 RDI: ffffffffffffff9c RBP: 00007fee5d843f91 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000000001df R11: 0000000000000246 R12: 0000000000000000 R13: 00007fee5da16218 R14: 00007fee5da16180 R15: 00007ffc64b988a8 INFO: task syz.2.179:7193 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.179 state:D stack:28952 pid:7193 tgid:7181 ppid:5797 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1480/0x50a0 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7241 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1dfe/0x25e0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xb5/0x160 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14f/0x750 kernel/locking/rwbase_rt.c:244 inode_lock_nested include/linux/fs.h:1072 [inline] __start_dirop fs/namei.c:2864 [inline] start_dirop fs/namei.c:2875 [inline] filename_create+0x1fb/0x360 fs/namei.c:4879 do_mkdirat+0xca/0x4b0 fs/namei.c:5156 __do_sys_mkdirat fs/namei.c:5186 [inline] __se_sys_mkdirat fs/namei.c:5184 [inline] __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:5184 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fee5d7bde97 RSP: 002b:00007fee5b5c0e68 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007fee5b5c0ef0 RCX: 00007fee5d7bde97 RDX: 00000000000001ff RSI: 0000200000000040 RDI: 00000000ffffff9c RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000040 R13: 00007fee5b5c0eb0 R14: 0000000000000000 R15: 0000000000000000 INFO: task syz.2.179:7195 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.179 state:D stack:26840 pid:7195 tgid:7181 ppid:5797 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1480/0x50a0 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7241 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1dfe/0x25e0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xb5/0x160 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14f/0x750 kernel/locking/rwbase_rt.c:244 inode_lock include/linux/fs.h:1027 [inline] open_last_lookups fs/namei.c:4537 [inline] path_openat+0xb53/0x3df0 fs/namei.c:4784 do_filp_open+0x1fa/0x410 fs/namei.c:4814 do_sys_openat2+0x121/0x200 fs/open.c:1430 do_sys_open fs/open.c:1436 [inline] __do_sys_openat fs/open.c:1452 [inline] __se_sys_openat fs/open.c:1447 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1447 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fee5d7bf749 RSP: 002b:00007fee5b19e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fee5da16360 RCX: 00007fee5d7bf749 RDX: 0000000000143041 RSI: 0000200000000040 RDI: ffffffffffffff9c RBP: 00007fee5d843f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fee5da163f8 R14: 00007fee5da16360 R15: 00007ffc64b988a8 Showing all locks held in the system: 4 locks held by kworker/u8:1/13: #0: ffff888140463938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff888140463938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc90000127b80 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc90000127b80 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 #2: ffff888063f2a0d0 (&type->s_umount_key#91){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563 #3: ffff88805af181e8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108 1 lock held by khungtaskd/39: #0: ffffffff8d5ae880 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d5ae880 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8d5ae880 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 5 locks held by kworker/u8:7/182: #0: ffff888019ad4938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff888019ad4938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc90003b37b80 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc90003b37b80 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 #2: ffffffff8e896200 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x7b0 net/core/net_namespace.c:670 #3: ffffffff8e8a3338 (rtnl_mutex){+.+.}-{4:4}, at: wg_netns_pre_exit+0x1c/0x200 drivers/net/wireguard/device.c:419 #4: ffff888059ccd7b8 (&wg->device_update_lock){+.+.}-{4:4}, at: wg_netns_pre_exit+0xb0/0x200 drivers/net/wireguard/device.c:424 5 locks held by kworker/u8:9/1274: 1 lock held by dhcpcd/5464: #0: ffffffff8e8a3338 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8e8a3338 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x323/0x1b20 net/ipv4/devinet.c:1120 2 locks held by getty/5554: #0: ffff8880352a50a0 (&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+0x44f/0x1460 drivers/tty/n_tty.c:2211 2 locks held by syz.2.179/7185: #0: ffff888063f2a480 (sb_writers#28){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499 #1: ffff88805af185b8 (&type->i_mutex_dir_key#21){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #1: ffff88805af185b8 (&type->i_mutex_dir_key#21){++++}-{4:4}, at: open_last_lookups fs/namei.c:4537 [inline] #1: ffff88805af185b8 (&type->i_mutex_dir_key#21){++++}-{4:4}, at: path_openat+0xb53/0x3df0 fs/namei.c:4784 2 locks held by syz.2.179/7191: #0: ffff888063f2a480 (sb_writers#28){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499 #1: ffff88805af185b8 (&type->i_mutex_dir_key#21/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1072 [inline] #1: ffff88805af185b8 (&type->i_mutex_dir_key#21/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2864 [inline] #1: ffff88805af185b8 (&type->i_mutex_dir_key#21/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2875 [inline] #1: ffff88805af185b8 (&type->i_mutex_dir_key#21/1){+.+.}-{4:4}, at: filename_create+0x1fb/0x360 fs/namei.c:4879 4 locks held by syz.2.179/7192: #0: ffff888063f2a480 (sb_writers#28){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499 #1: ffff88805af185b8 (&type->i_mutex_dir_key#21){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #1: ffff88805af185b8 (&type->i_mutex_dir_key#21){++++}-{4:4}, at: open_last_lookups fs/namei.c:4537 [inline] #1: ffff88805af185b8 (&type->i_mutex_dir_key#21){++++}-{4:4}, at: path_openat+0xb53/0x3df0 fs/namei.c:4784 #2: ffff88805af181e8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_create+0x1f5/0xa80 fs/jfs/namei.c:100 #3: ffff88805db71568 (&jfs_ip->commit_mutex/1){+.+.}-{4:4}, at: jfs_create+0x210/0xa80 fs/jfs/namei.c:101 2 locks held by syz.2.179/7193: #0: ffff888063f2a480 (sb_writers#28){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499 #1: ffff88805af185b8 (&type->i_mutex_dir_key#21/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1072 [inline] #1: ffff88805af185b8 (&type->i_mutex_dir_key#21/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2864 [inline] #1: ffff88805af185b8 (&type->i_mutex_dir_key#21/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2875 [inline] #1: ffff88805af185b8 (&type->i_mutex_dir_key#21/1){+.+.}-{4:4}, at: filename_create+0x1fb/0x360 fs/namei.c:4879 2 locks held by syz.2.179/7195: #0: ffff888063f2a480 (sb_writers#28){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499 #1: ffff88805af185b8 (&type->i_mutex_dir_key#21){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #1: ffff88805af185b8 (&type->i_mutex_dir_key#21){++++}-{4:4}, at: open_last_lookups fs/namei.c:4537 [inline] #1: ffff88805af185b8 (&type->i_mutex_dir_key#21){++++}-{4:4}, at: path_openat+0xb53/0x3df0 fs/namei.c:4784 2 locks held by syz.7.198/7616: #0: ffff888063f2a0d0 (&type->s_umount_key#91){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff888063f2a0d0 (&type->s_umount_key#91){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 #1: ffff8881423948c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:397 [inline] #1: ffff8881423948c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x1af/0xb80 fs/fs-writeback.c:2892 2 locks held by syz.6.259/7992: #0: ffff888063f2a0d0 (&type->s_umount_key#91){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff888063f2a0d0 (&type->s_umount_key#91){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 #1: ffff8881423948c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:397 [inline] #1: ffff8881423948c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x1af/0xb80 fs/fs-writeback.c:2892 7 locks held by syz-executor/8542: #0: ffff8880357d4480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2681 [inline] #0: ffff8880357d4480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682 #1: ffff88802a573078 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff8881433fde18 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff8881433fde18 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8e12a1f8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:234 #4: ffff88805bc5e0d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #4: ffff88805bc5e0d8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1104 [inline] #4: ffff88805bc5e0d8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x800 drivers/base/dd.c:1302 #5: ffff88805bc9c300 (&devlink->lock_key){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1777 #6: ffffffff8e8a3338 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #6: ffffffff8e8a3338 (rtnl_mutex){+.+.}-{4:4}, at: unregister_netdevice_notifier_net+0x8d/0x2a0 net/core/dev.c:2112 3 locks held by kworker/u8:31/8847: #0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc9000c70fb80 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000c70fb80 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 #2: ffffffff8e8a3338 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 1 lock held by syz-executor/8979: 4 locks held by syz.5.398/9008: 2 locks held by syz.8.399/9022: 2 locks held by syz.9.400/9023: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 39 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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:160 [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:346 [inline] watchdog+0xf95/0xfe0 kernel/hung_task.c:515 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 17 Comm: pr/legacy Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:io_serial_out+0x7c/0xc0 drivers/tty/serial/8250/8250_port.c:407 Code: f9 b5 fc 44 89 f9 d3 e5 49 83 ee 80 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 ac 60 18 fd 41 03 2e 89 d8 89 ea ee <5b> 41 5c 41 5e 41 5f 5d c3 cc cc cc cc cc 44 89 f9 80 e1 07 38 c1 RSP: 0018:ffffc90000167930 EFLAGS: 00000202 RAX: 000000000000002b RBX: 000000000000002b RCX: 0000000000000000 RDX: 00000000000003f8 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00000000000003f8 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffffff850a7820 R12: dffffc0000000000 R13: 0000000000000001 R14: ffffffff98f83d40 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888126e06000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055c5e8375138 CR3: 000000003726c000 CR4: 00000000003526f0 Call Trace: serial_port_out include/linux/serial_core.h:811 [inline] serial8250_console_putchar drivers/tty/serial/8250/8250_port.c:3192 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:-1 [inline] serial8250_console_write+0x1291/0x1b40 drivers/tty/serial/8250/8250_port.c:3342 console_emit_next_record kernel/printk/printk.c:3109 [inline] console_flush_one_record+0x6b5/0xbe0 kernel/printk/printk.c:3215 legacy_kthread_func+0x16f/0x210 kernel/printk/printk.c:3674 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246