INFO: task syz.2.57:5754 blocked for more than 143 seconds. Not tainted 6.11.0-rc5-syzkaller-00015-g3e9bff3bbe13 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.57 state:D stack:27392 pid:5754 tgid:5732 ppid:5216 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x17ae/0x4a10 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6621 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6678 rwsem_down_write_slowpath+0xeeb/0x13b0 kernel/locking/rwsem.c:1178 __down_write_common kernel/locking/rwsem.c:1306 [inline] __down_write kernel/locking/rwsem.c:1315 [inline] down_write_nested+0x1e0/0x220 kernel/locking/rwsem.c:1696 inode_lock_nested include/linux/fs.h:834 [inline] do_unlinkat+0x26a/0x830 fs/namei.c:4473 __do_sys_unlinkat fs/namei.c:4529 [inline] __se_sys_unlinkat fs/namei.c:4522 [inline] __x64_sys_unlinkat+0xcc/0xf0 fs/namei.c:4522 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f75def79e79 RSP: 002b:00007f75dfcf7038 EFLAGS: 00000246 ORIG_RAX: 0000000000000107 RAX: ffffffffffffffda RBX: 00007f75df116058 RCX: 00007f75def79e79 RDX: 0000000000000000 RSI: 0000000020000680 RDI: 0000000000000006 RBP: 00007f75defe793e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f75df116058 R15: 00007ffd238b5238 INFO: task syz.2.57:5755 blocked for more than 143 seconds. Not tainted 6.11.0-rc5-syzkaller-00015-g3e9bff3bbe13 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.57 state:D stack:26384 pid:5755 tgid:5732 ppid:5216 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x17ae/0x4a10 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6621 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6678 rwsem_down_write_slowpath+0xeeb/0x13b0 kernel/locking/rwsem.c:1178 __down_write_common kernel/locking/rwsem.c:1306 [inline] __down_write kernel/locking/rwsem.c:1315 [inline] down_write_nested+0x1e0/0x220 kernel/locking/rwsem.c:1696 inode_lock_nested include/linux/fs.h:834 [inline] filename_create+0x260/0x540 fs/namei.c:3979 do_mkdirat+0xbd/0x3a0 fs/namei.c:4225 __do_sys_mkdirat fs/namei.c:4248 [inline] __se_sys_mkdirat fs/namei.c:4246 [inline] __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4246 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f75def79e79 RSP: 002b:00007f75dfcd6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f75df116130 RCX: 00007f75def79e79 RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000000000005 RBP: 00007f75defe793e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f75df116130 R15: 00007ffd238b5238 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e738320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #0: ffffffff8e738320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e738320 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6626 7 locks held by kworker/u8:2/35: 3 locks held by kworker/u8:9/2942: #0: ffff88802a455148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline] #0: ffff88802a455148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312 #1: ffffc90009cffd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline] #1: ffffc90009cffd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312 #2: ffffffff8fa72608 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xd0/0x16f0 net/ipv6/addrconf.c:4194 3 locks held by kworker/u8:11/2975: #0: ffff888015489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline] #0: ffff888015489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312 #1: ffffc90009d1fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline] #1: ffffc90009d1fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312 #2: ffffffff8fa72608 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276 1 lock held by dhcpcd/4884: #0: ffffffff8fa72608 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0x2ce/0x1bc0 net/ipv4/devinet.c:1101 2 locks held by getty/4974: #0: ffff88802b99a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000312b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6ac/0x1e00 drivers/tty/n_tty.c:2211 3 locks held by syz.2.57/5733: 2 locks held by syz.2.57/5754: #0: ffff888059bbe420 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:515 #1: ffff8880614453b8 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:834 [inline] #1: ffff8880614453b8 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: do_unlinkat+0x26a/0x830 fs/namei.c:4473 2 locks held by syz.2.57/5755: #0: ffff888059bbe420 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:515 #1: ffff8880614453b8 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:834 [inline] #1: ffff8880614453b8 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: filename_create+0x260/0x540 fs/namei.c:3979 5 locks held by syz.4.77/5952: 7 locks held by syz-executor/7047: #0: ffff88801e908420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2881 [inline] #0: ffff88801e908420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x227/0xc90 fs/read_write.c:586 #1: ffff88807e083888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1eb/0x500 fs/kernfs/file.c:325 #2: ffff888022cc43c8 (kn->active#50){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20f/0x500 fs/kernfs/file.c:326 #3: ffffffff8f30ebc8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216 #4: ffff888056dab0e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #4: ffff888056dab0e8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1094 [inline] #4: ffff888056dab0e8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xce/0x7c0 drivers/base/dd.c:1292 #5: ffff888056dac250 (&devlink->lock_key#14){+.+.}-{3:3}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1672 #6: ffffffff8fa72608 (rtnl_mutex){+.+.}-{3:3}, at: nsim_destroy+0x71/0x5c0 drivers/net/netdevsim/netdev.c:773 1 lock held by syz-executor/7057: #0: ffffffff8fa72608 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fa72608 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6644 4 locks held by syz-executor/7081: #0: ffff88801e908420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2881 [inline] #0: ffff88801e908420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x227/0xc90 fs/read_write.c:586 #1: ffff88807e61fc88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1eb/0x500 fs/kernfs/file.c:325 #2: ffff888022cc43c8 (kn->active#50){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20f/0x500 fs/kernfs/file.c:326 #3: ffffffff8f30ebc8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216 1 lock held by syz.2.289/7239: #0: ffffffff8e73d6f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:328 [inline] #0: ffffffff8e73d6f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:958 1 lock held by syz.2.289/7240: #0: ffff888020a71360 (&lo->lo_mutex){+.+.}-{3:3}, at: loop_set_status+0x2a/0x900 drivers/block/loop.c:1252 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.11.0-rc5-syzkaller-00015-g3e9bff3bbe13 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Call Trace: __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xff4/0x1040 kernel/hung_task.c:379 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 7241 Comm: syz.2.289 Not tainted 6.11.0-rc5-syzkaller-00015-g3e9bff3bbe13 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 RIP: 0033:0x7f117143da46 Code: 39 d3 74 47 4c 8b 57 18 4c 8d 42 01 89 c1 83 c0 08 4c 89 47 28 41 0f b6 14 12 89 47 34 48 d3 e2 49 09 d1 39 f0 7c d5 44 89 ca <29> f0 89 f1 89 47 34 b8 01 00 00 00 49 d3 f9 48 d3 e0 44 89 4f 30 RSP: 002b:00007f1170ffe498 EFLAGS: 00000293 RAX: 0000000000000003 RBX: 00007f1170ffe540 RCX: 0000000000000000 RDX: 0000000000000006 RSI: 0000000000000000 RDI: 00007f1170ffe5e0 RBP: 0000000000000015 R08: 0000000000000002 R09: 0000000000000006 R10: 0000000000000002 R11: 00007f1170ffe550 R12: 0000000000000001 R13: 00007f11715fb880 R14: 0000000000000000 R15: 00007f1170ffe5e0 FS: 00007f1170fff6c0 GS: 0000000000000000