• Cong Wang's avatar
    idr: fix overflow case for idr_for_each_entry_ul() · e33d2b74
    Cong Wang authored
    idr_for_each_entry_ul() is buggy as it can't handle overflow
    case correctly. When we have an ID == UINT_MAX, it becomes an
    infinite loop. This happens when running on 32-bit CPU where
    unsigned long has the same size with unsigned int.
    
    There is no better way to fix this than casting it to a larger
    integer, but we can't just 64 bit integer on 32 bit CPU. Instead
    we could just use an additional integer to help us to detect this
    overflow case, that is, adding a new parameter to this macro.
    Fortunately tc action is its only user right now.
    
    Fixes: 65a206c0 ("net/sched: Change act_api and act_xxx modules to use IDR")
    Reported-by: default avatarLi Shuang <shuali@redhat.com>
    Tested-by: default avatarDavide Caratti <dcaratti@redhat.com>
    Cc: Matthew Wilcox <willy@infradead.org>
    Cc: Chris Mi <chrism@mellanox.com>
    Signed-off-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    e33d2b74
act_api.c 36.3 KB