| From | Ben Hutchings <> | Date | Sat, 27 Apr 2019 16:13:09 +0100 | Subject | [PATCH 3.16 096/202] s390/qeth: fix use-after-free in error path |
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3.16.66-rc1 review patch. If anyone has any objections, please let me know.
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From: Julian Wiedmann <jwi@linux.ibm.com>
commit afa0c5904ba16d59b0454f7ee4c807dae350f432 upstream.
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 <jwi@linux.ibm.com> Reviewed-by: Alexandra Winter <wintera@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.16: - Add the qeth_free_output_queue() function, which didn't exist here - Keep using kfree() to free to free the qeth_qdio_out_q structure] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- drivers/s390/net/qeth_core_main.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-)
--- a/drivers/s390/net/qeth_core_main.c +++ b/drivers/s390/net/qeth_core_main.c @@ -1288,6 +1288,15 @@ static void qeth_free_buffer_pool(struct } } +static void qeth_free_output_queue(struct qeth_qdio_out_q *q) +{ + if (!q) + return; + + qeth_clear_outq_buffers(q, 1); + kfree(q); +} + static void qeth_free_qdio_buffers(struct qeth_card *card) { int i, j; @@ -1308,10 +1317,8 @@ static void qeth_free_qdio_buffers(struc 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); - kfree(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; } @@ -2483,10 +2490,8 @@ out_freeoutqbufs: card->qdio.out_qs[i]->bufs[j] = NULL; } out_freeoutq: - while (i > 0) { - kfree(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:
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