• David Ahern's avatar
    netlink: Relax attr validation for fixed length types · 6e237d09
    David Ahern authored
    Commit 28033ae4 ("net: netlink: Update attr validation to require
    exact length for some types") requires attributes using types NLA_U* and
    NLA_S* to have an exact length. This change is exposing bugs in various
    userspace commands that are sending attributes with an invalid length
    (e.g., attribute has type NLA_U8 and userspace sends NLA_U32). While
    the commands are clearly broken and need to be fixed, users are arguing
    that the sudden change in enforcement is breaking older commands on
    newer kernels for use cases that otherwise "worked".
    
    Relax the validation to print a warning mesage similar to what is done
    for messages containing extra bytes after parsing.
    
    Fixes: 28033ae4 ("net: netlink: Update attr validation to require exact length for some types")
    Signed-off-by: 's avatarDavid Ahern <dsahern@gmail.com>
    Reviewed-by: 's avatarJohannes Berg <johannes@sipsolutions.net>
    Signed-off-by: 's avatarDavid S. Miller <davem@davemloft.net>
    6e237d09
nlattr.c 17.8 KB