INFO: task syz.4.3609:20002 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.4.3609 state:D stack:28992 pid:20002 tgid:19977 ppid:17000 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: 0033:0x7f05dab4def9 RSP: 002b:00007f05d9785038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f05dad06130 RCX: 00007f05dab4def9 RDX: 0000000000000001 RSI: 0000000020000000 RDI: 0000000000000005 RBP: 00007f05dabc0b76 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f05dad06130 R15: 00007ffc1abfb568 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 2 locks held by getty/2609: #0: ffff888100ea60a0 (&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 5 locks held by kworker/0:4/4933: #0: ffff888106687548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1277/0x1b40 kernel/workqueue.c:3206 #1: ffffc9000dc3fd80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x921/0x1b40 kernel/workqueue.c:3207 #2: ffff88810975d190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #2: ffff88810975d190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5849 #3: ffff888131437190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #3: ffff888131437190 (&dev->mutex){....}-{3:3}, at: usb_disconnect+0x10a/0x920 drivers/usb/core/hub.c:2295 #4: ffff888114110160 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #4: ffff888114110160 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1094 [inline] #4: ffff888114110160 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa4/0x610 drivers/base/dd.c:1292 7 locks held by kworker/0:5/4969: #0: ffff888106687548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1277/0x1b40 kernel/workqueue.c:3206 #1: ffffc9000edb7d80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x921/0x1b40 kernel/workqueue.c:3207 #2: ffff8881093dc190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #2: ffff8881093dc190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5849 #3: ffff888133eb6190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #3: ffff888133eb6190 (&dev->mutex){....}-{3:3}, at: usb_disconnect+0x10a/0x920 drivers/usb/core/hub.c:2295 #4: ffff8881311b1160 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #4: ffff8881311b1160 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1094 [inline] #4: ffff8881311b1160 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa4/0x610 drivers/base/dd.c:1292 #5: ffffffff89bab988 (input_mutex){+.+.}-{3:3}, at: __input_unregister_device+0x136/0x450 drivers/input/input.c:2275 #6: ffffffff88ec6df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock+0x1a4/0x3b0 kernel/rcu/tree_exp.h:328 4 locks held by udevd/4972: #0: ffff88811e3df1c8 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xde/0x12c0 fs/seq_file.c:182 #1: ffff888116661888 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff88810f73e968 (kn->active#18){++++}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff888133eb6190 (&dev->mutex){....}-{3:3}, at: device_lock_interruptible include/linux/device.h:1014 [inline] #3: ffff888133eb6190 (&dev->mutex){....}-{3:3}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 5 locks held by kworker/0:0/18955: #0: ffff888106687548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1277/0x1b40 kernel/workqueue.c:3206 #1: ffffc900123d7d80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x921/0x1b40 kernel/workqueue.c:3207 #2: ffff88810936d190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #2: ffff88810936d190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5849 #3: ffff88811cfe6190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #3: ffff88811cfe6190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1004 #4: ffff888113649160 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #4: ffff888113649160 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1004 1 lock held by syz.4.3609/20001: #0: ffff88811186a0b0 (&dev->io_mutex){+.+.}-{3:3}, at: yurex_write+0x17f/0x940 drivers/usb/misc/yurex.c:447 1 lock held by syz.4.3609/20002: #0: ffff88811186a0b0 (&dev->io_mutex){+.+.}-{3:3}, at: yurex_write+0x17f/0x940 drivers/usb/misc/yurex.c:447 1 lock held by syz.0.3940/21667: #0: ffffffff88ec6df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock+0x1a4/0x3b0 kernel/rcu/tree_exp.h:328 ============================================= NMI backtrace for cpu 1 CPU: 1 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 2530 Comm: syslogd 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:unwind_next_frame+0x57/0x23a0 arch/x86/kernel/unwind_orc.c:682 Code: 04 02 84 c0 74 08 3c 03 0f 8e 0f 0d 00 00 8b 2b 31 ff 89 ee e8 6a 37 3f 00 85 ed 75 1c 31 db e8 1f 35 3f 00 89 d8 48 83 c4 40 <5b> 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc e8 05 35 3f 00 48 8d RSP: 0018:ffffc900015ff510 EFLAGS: 00000282 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff8115701f RDX: ffff8881156a3a80 RSI: ffffffff81155e71 RDI: 0000000000000005 RBP: ffffc900015ff900 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000080000000 R11: 0000000000000000 R12: ffffc900015f8000 R13: ffffc90001600000 R14: ffffc900015ff908 R15: ffffc900015ff8e8 FS: 00007f9eb760b380(0000) GS:ffff8881f5800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7fc758efe0 CR3: 00000001157e8000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0x100/0x170 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x95/0xd0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579 poison_slab_object+0xf7/0x160 mm/kasan/common.c:240 __kasan_slab_free+0x14/0x30 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2256 [inline] slab_free mm/slub.c:4477 [inline] kfree+0x10b/0x380 mm/slub.c:4598 skb_kfree_head net/core/skbuff.c:1084 [inline] skb_free_head+0x108/0x1d0 net/core/skbuff.c:1096 skb_release_data+0x772/0x920 net/core/skbuff.c:1123 skb_release_all net/core/skbuff.c:1188 [inline] __kfree_skb net/core/skbuff.c:1202 [inline] consume_skb net/core/skbuff.c:1426 [inline] consume_skb+0xd0/0x160 net/core/skbuff.c:1420 __unix_dgram_recvmsg+0x81c/0xdd0 net/unix/af_unix.c:2527 unix_dgram_recvmsg+0xd0/0x110 net/unix/af_unix.c:2544 sock_recvmsg_nosec net/socket.c:1046 [inline] sock_recvmsg+0x1f6/0x250 net/socket.c:1068 sock_read_iter+0x2c7/0x3c0 net/socket.c:1138 new_sync_read fs/read_write.c:395 [inline] vfs_read+0xa39/0xbd0 fs/read_write.c:476 ksys_read+0x1f8/0x260 fs/read_write.c:619 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: 0033:0x7f9eb775fb6a Code: 00 3d 00 00 41 00 75 0d 50 48 8d 3d 2d 08 0a 00 e8 ea 7d 01 00 31 c0 e9 07 ff ff ff 64 8b 04 25 18 00 00 00 85 c0 75 1b 0f 05 <48> 3d 00 f0 ff ff 76 6c 48 8b 15 8f a2 0d 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffc2f64fa38 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f9eb775fb6a RDX: 00000000000000ff RSI: 0000560895f35300 RDI: 0000000000000000 RBP: 0000560895f352c0 R08: 0000000000000001 R09: 0000000000000000 R10: 00007f9eb78fe3a3 R11: 0000000000000246 R12: 0000560895f3533a R13: 0000560895f35300 R14: 0000000000000000 R15: 00007f9eb7942a80