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authorMin Li <lm0963hack@gmail.com>2023-03-04 21:50:35 +0800
committerLuiz Augusto von Dentz <luiz.von.dentz@intel.com>2023-03-22 16:05:55 -0700
commit1c66bee492a5fe00ae3fe890bb693bfc99f994c6 (patch)
tree7a2e1a88a871ec10a20a28a6112babdd26926345
parent294d749b5df5a22d17989833fb1a0a2cd1dfd243 (diff)
Bluetooth: Fix race condition in hci_cmd_sync_clear
There is a potential race condition in hci_cmd_sync_work and hci_cmd_sync_clear, and could lead to use-after-free. For instance, hci_cmd_sync_work is added to the 'req_workqueue' after cancel_work_sync The entry of 'cmd_sync_work_list' may be freed in hci_cmd_sync_clear, and causing kernel panic when it is used in 'hci_cmd_sync_work'. Here's the call trace: dump_stack_lvl+0x49/0x63 print_report.cold+0x5e/0x5d3 ? hci_cmd_sync_work+0x282/0x320 kasan_report+0xaa/0x120 ? hci_cmd_sync_work+0x282/0x320 __asan_report_load8_noabort+0x14/0x20 hci_cmd_sync_work+0x282/0x320 process_one_work+0x77b/0x11c0 ? _raw_spin_lock_irq+0x8e/0xf0 worker_thread+0x544/0x1180 ? poll_idle+0x1e0/0x1e0 kthread+0x285/0x320 ? process_one_work+0x11c0/0x11c0 ? kthread_complete_and_exit+0x30/0x30 ret_from_fork+0x22/0x30 </TASK> Allocated by task 266: kasan_save_stack+0x26/0x50 __kasan_kmalloc+0xae/0xe0 kmem_cache_alloc_trace+0x191/0x350 hci_cmd_sync_queue+0x97/0x2b0 hci_update_passive_scan+0x176/0x1d0 le_conn_complete_evt+0x1b5/0x1a00 hci_le_conn_complete_evt+0x234/0x340 hci_le_meta_evt+0x231/0x4e0 hci_event_packet+0x4c5/0xf00 hci_rx_work+0x37d/0x880 process_one_work+0x77b/0x11c0 worker_thread+0x544/0x1180 kthread+0x285/0x320 ret_from_fork+0x22/0x30 Freed by task 269: kasan_save_stack+0x26/0x50 kasan_set_track+0x25/0x40 kasan_set_free_info+0x24/0x40 ____kasan_slab_free+0x176/0x1c0 __kasan_slab_free+0x12/0x20 slab_free_freelist_hook+0x95/0x1a0 kfree+0xba/0x2f0 hci_cmd_sync_clear+0x14c/0x210 hci_unregister_dev+0xff/0x440 vhci_release+0x7b/0xf0 __fput+0x1f3/0x970 ____fput+0xe/0x20 task_work_run+0xd4/0x160 do_exit+0x8b0/0x22a0 do_group_exit+0xba/0x2a0 get_signal+0x1e4a/0x25b0 arch_do_signal_or_restart+0x93/0x1f80 exit_to_user_mode_prepare+0xf5/0x1a0 syscall_exit_to_user_mode+0x26/0x50 ret_from_fork+0x15/0x30 Fixes: 6a98e3836fa2 ("Bluetooth: Add helper for serialized HCI command execution") Cc: stable@vger.kernel.org Signed-off-by: Min Li <lm0963hack@gmail.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
-rw-r--r--net/bluetooth/hci_sync.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
index 7e152e912e8c..5b8dc8fb2e27 100644
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -643,6 +643,7 @@ void hci_cmd_sync_clear(struct hci_dev *hdev)
cancel_work_sync(&hdev->cmd_sync_work);
cancel_work_sync(&hdev->reenable_adv_work);
+ mutex_lock(&hdev->cmd_sync_work_lock);
list_for_each_entry_safe(entry, tmp, &hdev->cmd_sync_work_list, list) {
if (entry->destroy)
entry->destroy(hdev, entry->data, -ECANCELED);
@@ -650,6 +651,7 @@ void hci_cmd_sync_clear(struct hci_dev *hdev)
list_del(&entry->list);
kfree(entry);
}
+ mutex_unlock(&hdev->cmd_sync_work_lock);
}
void __hci_cmd_sync_cancel(struct hci_dev *hdev, int err)