From afa0c5904ba16d59b0454f7ee4c807dae350f432 Mon Sep 17 00:00:00 2001 From: Julian Wiedmann Date: Mon, 4 Feb 2019 17:40:07 +0100 Subject: [PATCH] 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: 0da9581ddb0f ("qeth: exploit asynchronous delivery of storage blocks") Signed-off-by: Julian Wiedmann Reviewed-by: Alexandra Winter Signed-off-by: David S. Miller --- drivers/s390/net/qeth_core_main.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c index ca62e7d3ee93..30679bfc8a1b 100644 --- a/drivers/s390/net/qeth_core_main.c +++ b/drivers/s390/net/qeth_core_main.c @@ -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; }