Hi Vamshi, > kmemleak report: > unreferenced object 0xffff9b1127f00500 (size 208): > comm "kworker/u17:2", pid 500, jiffies 4294937470 (age 580.136s) > hex dump (first 32 bytes): > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > 00 60 ed 05 11 9b ff ff 00 00 00 00 00 00 00 00 .`.............. > backtrace: > [<000000006ab3fd59>] kmem_cache_alloc_node+0x17a/0x480 > [<0000000051a5f6f9>] __alloc_skb+0x5b/0x1d0 > [<0000000037e2d252>] hci_prepare_cmd+0x32/0xc0 [bluetooth] > [<0000000010b586d5>] hci_req_add_ev+0x84/0xe0 [bluetooth] > [<00000000d2deb520>] hci_req_clear_event_filter+0x42/0x70 [bluetooth] > [<00000000f864bd8c>] hci_req_prepare_suspend+0x84/0x470 [bluetooth] > [<000000001deb2cc4>] hci_prepare_suspend+0x31/0x40 [bluetooth] > [<000000002677dd79>] process_one_work+0x209/0x3b0 > [<00000000aaa62b07>] worker_thread+0x34/0x400 > [<00000000826d176c>] kthread+0x126/0x140 > [<000000002305e558>] ret_from_fork+0x22/0x30 > unreferenced object 0xffff9b1125c6ee00 (size 512): > comm "kworker/u17:2", pid 500, jiffies 4294937470 (age 580.136s) > hex dump (first 32 bytes): > 04 00 00 00 0d 00 00 00 05 0c 01 00 11 9b ff ff ................ > 00 00 00 00 00 00 00 00 01 00 00 00 00 00 00 00 ................ > backtrace: > [<000000009f07c0cc>] slab_post_alloc_hook+0x59/0x270 > [<0000000049431dc2>] __kmalloc_node_track_caller+0x15f/0x330 > [<00000000027a42f6>] __kmalloc_reserve.isra.70+0x31/0x90 > [<00000000e8e3e76a>] __alloc_skb+0x87/0x1d0 > [<0000000037e2d252>] hci_prepare_cmd+0x32/0xc0 [bluetooth] > [<0000000010b586d5>] hci_req_add_ev+0x84/0xe0 [bluetooth] > [<00000000d2deb520>] hci_req_clear_event_filter+0x42/0x70 [bluetooth] > [<00000000f864bd8c>] hci_req_prepare_suspend+0x84/0x470 [bluetooth] > [<000000001deb2cc4>] hci_prepare_suspend+0x31/0x40 [bluetooth] > [<000000002677dd79>] process_one_work+0x209/0x3b0 > [<00000000aaa62b07>] worker_thread+0x34/0x400 > [<00000000826d176c>] kthread+0x126/0x140 > [<000000002305e558>] ret_from_fork+0x22/0x30 > unreferenced object 0xffff9b112b395788 (size 8): > comm "kworker/u17:2", pid 500, jiffies 4294937470 (age 580.136s) > hex dump (first 8 bytes): > 20 00 00 00 00 00 04 00 ....... > backtrace: > [<0000000052dc28d2>] kmem_cache_alloc_trace+0x15e/0x460 > [<0000000046147591>] alloc_ctrl_urb+0x52/0xe0 [btusb] > [<00000000a2ed3e9e>] btusb_send_frame+0x91/0x100 [btusb] > [<000000001e66030e>] hci_send_frame+0x7e/0xf0 [bluetooth] > [<00000000bf6b7269>] hci_cmd_work+0xc5/0x130 [bluetooth] > [<000000002677dd79>] process_one_work+0x209/0x3b0 > [<00000000aaa62b07>] worker_thread+0x34/0x400 > [<00000000826d176c>] kthread+0x126/0x140 > [<000000002305e558>] ret_from_fork+0x22/0x30 > > In pm sleep-resume context, while the btusb device rebinds, it enters > hci_unregister_dev(), whilst there is a possibility of hdev receiving > PM_POST_SUSPEND suspend_notifier event, leading to generation of msg > frames. When hci_unregister_dev() completes, i.e. hdev context is > destroyed/freed, those intermittently sent msg frames cause memory > leak. > > BUG details: > Below is stack trace of thread that enters hci_unregister_dev(), marks > the hdev flag HCI_UNREGISTER to 1, and then goes onto to wait on notifier > lock - refer unregister_pm_notifier(). > > hci_unregister_dev+0xa5/0x320 [bluetoot] > btusb_disconnect+0x68/0x150 [btusb] > usb_unbind_interface+0x77/0x250 > ? kernfs_remove_by_name_ns+0x75/0xa0 > device_release_driver_internal+0xfe/0x1 > device_release_driver+0x12/0x20 > bus_remove_device+0xe1/0x150 > device_del+0x192/0x3e0 > ? usb_remove_ep_devs+0x1f/0x30 > usb_disable_device+0x92/0x1b0 > usb_disconnect+0xc2/0x270 > hub_event+0x9f6/0x15d0 > ? rpm_idle+0x23/0x360 > ? rpm_idle+0x26b/0x360 > process_one_work+0x209/0x3b0 > worker_thread+0x34/0x400 > ? process_one_work+0x3b0/0x3b0 > kthread+0x126/0x140 > ? kthread_park+0x90/0x90 > ret_from_fork+0x22/0x30 > > Below is stack trace of thread executing hci_suspend_notifier() which > processes the PM_POST_SUSPEND event, while the unbinding thread is > waiting on lock. > > hci_suspend_notifier.cold.39+0x5/0x2b [bluetooth] > blocking_notifier_call_chain+0x69/0x90 > pm_notifier_call_chain+0x1a/0x20 > pm_suspend.cold.9+0x334/0x352 > state_store+0x84/0xf0 > kobj_attr_store+0x12/0x20 > sysfs_kf_write+0x3b/0x40 > kernfs_fop_write+0xda/0x1c0 > vfs_write+0xbb/0x250 > ksys_write+0x61/0xe0 > __x64_sys_write+0x1a/0x20 > do_syscall_64+0x37/0x80 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > Fix hci_suspend_notifer(), not to act on events when flag HCI_UNREGISTER > is set. > > Signed-off-by: Vamshi K Sthambamkadi <vamshi.k.sthambamkadi@xxxxxxxxx> > --- > net/bluetooth/hci_core.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) patch has been applied to bluetooth-next tree. Regards Marcel
