INFO: task syz.2.2672:14239 blocked for more than 143 seconds. Not tainted 6.11.0-rc7-syzkaller-00152-g68d4209158f4 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.2672 state:D stack:28352 pid:14239 tgid:14238 ppid:2657 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0xcda/0x2f80 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6621 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6678 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x5b8/0x9c0 kernel/locking/mutex.c:752 yurex_write+0x17f/0x940 drivers/usb/misc/yurex.c:447 vfs_write+0x29a/0x1140 fs/read_write.c:588 ksys_write+0x12f/0x260 fs/read_write.c:643 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f69179fdef9 RSP: 002b:00007f6916677038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f6917bb5f80 RCX: 00007f69179fdef9 RDX: 0000000000000001 RSI: 0000000020000000 RDI: 0000000000000004 RBP: 00007f6917a70b76 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f6917bb5f80 R15: 00007ffd15280498 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff88ebb660 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #0: ffffffff88ebb660 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff88ebb660 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6626 1 lock held by klogd/2537: #0: ffff8881f593d718 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:560 [inline] #0: ffff8881f593d718 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock kernel/sched/sched.h:1415 [inline] #0: ffff8881f593d718 (&rq->__lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1714 [inline] #0: ffff8881f593d718 (&rq->__lock){-.-.}-{2:2}, at: __schedule+0x28e/0x2f80 kernel/sched/core.c:6436 2 locks held by getty/2606: #0: ffff888106b0f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900000432f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfc8/0x1490 drivers/tty/n_tty.c:2211 3 locks held by kworker/0:3/4932: 3 locks held by kworker/0:5/5091: 3 locks held by kworker/u8:1/10863: #0: ffff888100abb148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x1277/0x1b40 kernel/workqueue.c:3206 #1: ffffc9000167fd80 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x921/0x1b40 kernel/workqueue.c:3207 #2: ffffffff8a161d50 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xbb/0xbb0 net/core/net_namespace.c:594 5 locks held by kworker/0:6/13617: #0: ffff888105ebad48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1277/0x1b40 kernel/workqueue.c:3206 #1: ffffc90010497d80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x921/0x1b40 kernel/workqueue.c:3207 #2: ffff88810937d190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #2: ffff88810937d190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5849 #3: ffff888119f0f190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #3: ffff888119f0f190 (&dev->mutex){....}-{3:3}, at: usb_disconnect+0x10a/0x920 drivers/usb/core/hub.c:2295 #4: ffff888119f0b160 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #4: ffff888119f0b160 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1094 [inline] #4: ffff888119f0b160 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa4/0x610 drivers/base/dd.c:1292 1 lock held by syz.2.2672/14239: #0: ffff8881115f6cb0 (&dev->io_mutex#2){+.+.}-{3:3}, at: yurex_write+0x17f/0x940 drivers/usb/misc/yurex.c:447 1 lock held by syz.2.2672/14252: #0: ffff8881115f6cb0 (&dev->io_mutex#2){+.+.}-{3:3}, at: yurex_write+0x17f/0x940 drivers/usb/misc/yurex.c:447 1 lock held by syz-executor/16461: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.11.0-rc7-syzkaller-00152-g68d4209158f4 #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+0x116/0x1f0 lib/dump_stack.c:119 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 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+0xf0c/0x1240 kernel/hung_task.c:379 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 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: 16727 Comm: syz.4.3085 Not tainted 6.11.0-rc7-syzkaller-00152-g68d4209158f4 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 RIP: 0010:instrument_atomic_read include/linux/instrumented.h:68 [inline] RIP: 0010:atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] RIP: 0010:page_ref_count include/linux/page_ref.h:67 [inline] RIP: 0010:folio_ref_count include/linux/page_ref.h:89 [inline] RIP: 0010:page_count include/linux/page_ref.h:94 [inline] RIP: 0010:page_is_buddy mm/internal.h:526 [inline] RIP: 0010:find_buddy_page_pfn mm/internal.h:578 [inline] RIP: 0010:__free_one_page+0x7a9/0xaa0 mm/page_alloc.c:791 Code: 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 1e 02 00 00 48 8b 43 48 a8 01 0f 84 f7 fb ff ff 48 83 e8 01 48 89 44 24 18 48 8b 44 24 18 04 00 00 00 48 8d 78 34 48 89 7c 24 20 e8 34 10 09 00 48 8b 7c RSP: 0018:ffffc90014be7860 EFLAGS: 00000046 RAX: ffffea0004e7a700 RBX: ffffea0004e7a700 RCX: 0000000000000001 RDX: 0000000000000002 RSI: ffffea0004e7a788 RDI: ffffea0004e7a708 RBP: 0000000000000001 R08: dffffc0000000000 R09: fffff940009cf4f6 R10: ffffea0004e7a7b7 R11: ffff8881f59432a0 R12: 0000000000139e9c R13: 0000000000139e9e R14: ffffea0004e7a780 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881f5900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1edb121440 CR3: 000000011590e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: free_pcppages_bulk+0x2e3/0x620 mm/page_alloc.c:1194 free_unref_page_commit+0x575/0xd50 mm/page_alloc.c:2594 free_unref_page+0x799/0xce0 mm/page_alloc.c:2642 vfree+0x181/0x7a0 mm/vmalloc.c:3367 kcov_put kernel/kcov.c:438 [inline] kcov_put+0x2a/0x40 kernel/kcov.c:434 kcov_close+0x10/0x20 kernel/kcov.c:534 __fput+0x408/0xbb0 fs/file_table.c:422 task_work_run+0x14e/0x250 kernel/task_work.c:228 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xaa3/0x2b30 kernel/exit.c:882 do_group_exit+0xd3/0x2a0 kernel/exit.c:1031 get_signal+0x25fb/0x2770 kernel/signal.c:2917 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x147/0x260 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc8c6c6def9 Code: Unable to access opcode bytes at 0x7fc8c6c6decf. RSP: 002b:00007fc8c58a50e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007fc8c6e26138 RCX: 00007fc8c6c6def9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fc8c6e26138 RBP: 00007fc8c6e26130 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fc8c6e2613c R13: 0000000000000000 R14: 00007ffc71b25c80 R15: 00007ffc71b25d68