• Sven Eckelmann's avatar
    batman-adv: Fix double free during fragment merge error · 248e23b5
    Sven Eckelmann authored
    The function batadv_frag_skb_buffer was supposed not to consume the skbuff
    on errors. This was followed in the helper function
    batadv_frag_insert_packet when the skb would potentially be inserted in the
    fragment queue. But it could happen that the next helper function
    batadv_frag_merge_packets would try to merge the fragments and fail. This
    results in a kfree_skb of all the enqueued fragments (including the just
    inserted one). batadv_recv_frag_packet would detect the error in
    batadv_frag_skb_buffer and try to free the skb again.
    
    The behavior of batadv_frag_skb_buffer (and its helper
    batadv_frag_insert_packet) must therefore be changed to always consume the
    skbuff to have a common behavior and avoid the double kfree_skb.
    
    Fixes: 610bfc6b ("batman-adv: Receive fragmented packets and merge")
    Signed-off-by: default avatarSven Eckelmann <sven@narfation.org>
    Signed-off-by: default avatarSimon Wunderlich <sw@simonwunderlich.de>
    248e23b5
fragmentation.c 15.9 KB