When qeth_qdio_handle_aob() frees dangling allocations in the notified TX buffer, there are rare tear-down cases where qeth_drain_output_queue() would later call qeth_clear_output_buffer() for the same buffer - and thus end up walking the buffer a second time to check for dangling kmem_cache allocations. Luckily current code previously scrubs such a buffer, so qeth_clear_output_buffer() would find buf->buffer->element[i].addr as NULL and not do anything. But this is fragile, and we can easily improve it by consistently clearing the ->is_header flag after freeing the allocation. Signed-off-by: Julian Wiedmann <jwi@xxxxxxxxxxxxx> --- drivers/s390/net/qeth_core_main.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c index da27ef451d05..f4b60294a969 100644 --- a/drivers/s390/net/qeth_core_main.c +++ b/drivers/s390/net/qeth_core_main.c @@ -546,6 +546,7 @@ static void qeth_qdio_handle_aob(struct qeth_card *card, if (data && buffer->is_header[i]) kmem_cache_free(qeth_core_header_cache, data); + buffer->is_header[i] = 0; } atomic_set(&buffer->state, QETH_QDIO_BUF_EMPTY); -- 2.17.1
