• Eric Dumazet's avatar
    ipv6: do not clear pinet6 field · f77d6021
    Eric Dumazet authored
    We have seen multiple NULL dereferences in __inet6_lookup_established()
    
    After analysis, I found that inet6_sk() could be NULL while the
    check for sk_family == AF_INET6 was true.
    
    Bug was added in linux-2.6.29 when RCU lookups were introduced in UDP
    and TCP stacks.
    
    Once an IPv6 socket, using SLAB_DESTROY_BY_RCU is inserted in a hash
    table, we no longer can clear pinet6 field.
    
    This patch extends logic used in commit fcbdf09d
    ("net: fix nulls list corruptions in sk_prot_alloc")
    
    TCP/UDP/UDPLite IPv6 protocols provide their own .clear_sk() method
    to make sure we do not clear pinet6 field.
    
    At socket clone phase, we do not really care, as cloning the parent (non
    NULL) pinet6 is not adding a fatal race.
    Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    f77d6021
udplite.c 3.39 KB