From e521813468f786271a87e78e8644243bead48fad Mon Sep 17 00:00:00 2001 From: Julian Wiedmann Date: Wed, 2 May 2018 08:48:43 +0200 Subject: [PATCH] s390/qdio: fix access to uninitialized qdio_q fields Ever since CQ/QAOB support was added, calling qdio_free() straight after qdio_alloc() results in qdio_release_memory() accessing uninitialized memory (ie. q->u.out.use_cq and q->u.out.aobs). Followed by a kmem_cache_free() on the random AOB addresses. For older kernels that don't have 6e30c549f6ca, the same applies if qdio_establish() fails in the DEV_STATE_ONLINE check. While initializing q->u.out.use_cq would be enough to fix this particular bug, the more future-proof change is to just zero-alloc the whole struct. Fixes: 104ea556ee7f ("qdio: support asynchronous delivery of storage blocks") Cc: #v3.2+ Signed-off-by: Julian Wiedmann Signed-off-by: Martin Schwidefsky --- drivers/s390/cio/qdio_setup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/s390/cio/qdio_setup.c b/drivers/s390/cio/qdio_setup.c index 439991d71b14..22ddb49e0f50 100644 --- a/drivers/s390/cio/qdio_setup.c +++ b/drivers/s390/cio/qdio_setup.c @@ -141,7 +141,7 @@ static int __qdio_allocate_qs(struct qdio_q **irq_ptr_qs, int nr_queues) int i; for (i = 0; i < nr_queues; i++) { - q = kmem_cache_alloc(qdio_q_cache, GFP_KERNEL); + q = kmem_cache_zalloc(qdio_q_cache, GFP_KERNEL); if (!q) return -ENOMEM;