• Julian Wiedmann's avatar
    s390/qeth: fix qdio teardown after early init error · 8b5026bc
    Julian Wiedmann authored
    qeth_l?_set_online() goes through a number of initialization steps, and
    on any error uses qeth_l?_stop_card() to tear down the residual state.
    
    The first initialization step is qeth_core_hardsetup_card(). When this
    fails after having established a QDIO context on the device
    (ie. somewhere after qeth_mpc_initialize()), qeth_l?_stop_card() doesn't
    shut down this QDIO context again (since the card state hasn't
    progressed from DOWN at this stage).
    
    Even worse, we then call qdio_free() as final teardown step to free the
    QDIO data structures - while some of them are still hooked into wider
    QDIO infrastructure such as the IRQ list. This is inevitably followed by
    use-after-frees and other nastyness.
    
    Fix this by unconditionally calling qeth_qdio_clear_card() to shut down
    the QDIO context, and also to halt/clear any pending activity on the
    various IO channels.
    Remove the naive attempt at handling the teardown in
    qeth_mpc_initialize(), it clearly doesn't suffice and we're handling it
    properly now in the wider teardown code.
    
    Fixes: 4a71df50 ("qeth: new qeth device driver")
    Signed-off-by: default avatarJulian Wiedmann <jwi@linux.ibm.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    8b5026bc
qeth_l3_main.c 63.8 KB