s390/qeth: fix use-after-free in error path

The error path in qeth_alloc_qdio_buffers() that takes care of
cleaning up the Output Queues is buggy. It first frees the queue, but
then calls qeth_clear_outq_buffers() with that very queue struct.

Make the call to qeth_clear_outq_buffers() part of the free action
(in the correct order), and while at it fix the naming of the helper.

Fixes: 0da9581ddb ("qeth: exploit asynchronous delivery of storage blocks")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Julian Wiedmann 2019-02-04 17:40:07 +01:00 committed by David S. Miller
parent 5065b2dd3e
commit afa0c5904b
1 changed files with 6 additions and 9 deletions

View File

@ -2395,11 +2395,12 @@ static int qeth_init_qdio_out_buf(struct qeth_qdio_out_q *q, int bidx)
return 0;
}
static void qeth_free_qdio_out_buf(struct qeth_qdio_out_q *q)
static void qeth_free_output_queue(struct qeth_qdio_out_q *q)
{
if (!q)
return;
qeth_clear_outq_buffers(q, 1);
qdio_free_buffers(q->qdio_bufs, QDIO_MAX_BUFFERS_PER_Q);
kfree(q);
}
@ -2473,10 +2474,8 @@ static int qeth_alloc_qdio_buffers(struct qeth_card *card)
card->qdio.out_qs[i]->bufs[j] = NULL;
}
out_freeoutq:
while (i > 0) {
qeth_free_qdio_out_buf(card->qdio.out_qs[--i]);
qeth_clear_outq_buffers(card->qdio.out_qs[i], 1);
}
while (i > 0)
qeth_free_output_queue(card->qdio.out_qs[--i]);
kfree(card->qdio.out_qs);
card->qdio.out_qs = NULL;
out_freepool:
@ -2509,10 +2508,8 @@ static void qeth_free_qdio_buffers(struct qeth_card *card)
qeth_free_buffer_pool(card);
/* free outbound qdio_qs */
if (card->qdio.out_qs) {
for (i = 0; i < card->qdio.no_out_queues; ++i) {
qeth_clear_outq_buffers(card->qdio.out_qs[i], 1);
qeth_free_qdio_out_buf(card->qdio.out_qs[i]);
}
for (i = 0; i < card->qdio.no_out_queues; i++)
qeth_free_output_queue(card->qdio.out_qs[i]);
kfree(card->qdio.out_qs);
card->qdio.out_qs = NULL;
}