• Luiz Augusto von Dentz's avatar
    Bluetooth: af_bluetooth: Fix deadlock · f7b94bdc
    Luiz Augusto von Dentz authored
    Attemting to do sock_lock on .recvmsg may cause a deadlock as shown
    bellow, so instead of using sock_sock this uses sk_receive_queue.lock
    on bt_sock_ioctl to avoid the UAF:
    
    INFO: task kworker/u9:1:121 blocked for more than 30 seconds.
          Not tainted 6.7.6-lemon #183
    Workqueue: hci0 hci_rx_work
    Call Trace:
     <TASK>
     __schedule+0x37d/0xa00
     schedule+0x32/0xe0
     __lock_sock+0x68/0xa0
     ? __pfx_autoremove_wake_function+0x10/0x10
     lock_sock_nested+0x43/0x50
     l2cap_sock_recv_cb+0x21/0xa0
     l2cap_recv_frame+0x55b/0x30a0
     ? psi_task_switch+0xeb/0x270
     ? finish_task_switch.isra.0+0x93/0x2a0
     hci_rx_work+0x33a/0x3f0
     process_one_work+0x13a/0x2f0
     worker_thread+0x2f0/0x410
     ? __pfx_worker_thread+0x10/0x10
     kthread+0xe0/0x110
     ? __pfx_kthread+0x10/0x10
     ret_from_fork+0x2c/0x50
     ? __pfx_kthread+0x10/0x10
     ret_from_fork_asm+0x1b/0x30
     </TASK>
    
    Fixes: 2e07e834 ("Bluetooth: af_bluetooth: Fix Use-After-Free in bt_sock_recvmsg")
    Signed-off-by: default avatarLuiz Augusto von Dentz <luiz.von.dentz@intel.com>
    f7b94bdc
af_bluetooth.c 18.5 KB