| Message ID | 20210114095853.GA1650@cosmos |
|---|---|
| State | Accepted |
| Commit | 5ff20cbe6752a5bc06ff58fee8aa11a0d5075819 |
| Headers | show |
| Series | Bluetooth: btusb: fix memory leak on suspend and resume | expand |
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c index 9d2c9a1c552f..29c88dbbc3fe 100644 --- a/net/bluetooth/hci_core.c +++ b/net/bluetooth/hci_core.c @@ -3566,7 +3566,8 @@ static int hci_suspend_notifier(struct notifier_block *nb, unsigned long action, } /* Suspend notifier should only act on events when powered. */ - if (!hdev_is_powered(hdev)) + if (!hdev_is_powered(hdev) || + !hci_dev_test_flag(hdev, HCI_UNREGISTER)) goto done; if (action == PM_SUSPEND_PREPARE) {
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@gmail.com> --- net/bluetooth/hci_core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)