• Pauli Virtanen's avatar
    Bluetooth: fix use-after-free in accessing skb after sending it · 947ec0d0
    Pauli Virtanen authored
    hci_send_cmd_sync first sends skb and then tries to clone it.  However,
    the driver may have already freed the skb at that point.
    
    Fix by cloning the sent_cmd cloned just above, instead of the original.
    
    Log:
    ================================================================
    BUG: KASAN: slab-use-after-free in __copy_skb_header+0x1a/0x240
    ...
    Call Trace: ..
     __skb_clone+0x59/0x2c0
     hci_cmd_work+0x3b3/0x3d0 [bluetooth]
     process_one_work+0x459/0x900
    ...
    Allocated by task 129: ...
     __alloc_skb+0x1ae/0x220
     __hci_cmd_sync_sk+0x44c/0x7a0 [bluetooth]
     __hci_cmd_sync_status+0x24/0xb0 [bluetooth]
     set_cig_params_sync+0x778/0x7d0 [bluetooth]
    ...
    Freed by task 0: ...
     kmem_cache_free+0x157/0x3c0
     __usb_hcd_giveback_urb+0x11e/0x1e0
     usb_giveback_urb_bh+0x1ad/0x2a0
     tasklet_action_common.isra.0+0x259/0x4a0
     __do_softirq+0x15b/0x5a7
    ================================================================
    
    Fixes: 2615fd9a ("Bluetooth: hci_sync: Fix overwriting request callback")
    Signed-off-by: default avatarPauli Virtanen <pav@iki.fi>
    Signed-off-by: default avatarLuiz Augusto von Dentz <luiz.von.dentz@intel.com>
    947ec0d0
hci_core.c 96.4 KB