[PATCH] virtio_ring: check desc == NULL when packed and indirect
From: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Date: 2021-09-27 03:06:27
Subsystem:
the rest, virtio core · Maintainers:
Linus Torvalds, "Michael S. Tsirkin", Jason Wang, Eugenio Pérez
In the case of packed, use indirect desc, since desc is allocated by
kmalloc_array(), we should check whether its return value is NULL.
Fixes: 1ce9e6055fa ("virtio_ring: introduce packed ring support")
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
---
drivers/virtio/virtio_ring.c | 27 ++++++++++++++++-----------
1 file changed, 16 insertions(+), 11 deletions(-)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index dd95dfd85e98..7dd381eae725 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c@@ -1050,21 +1050,20 @@ static struct vring_packed_desc *alloc_indirect_packed(unsigned int total_sg, } static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, - struct scatterlist *sgs[], - unsigned int total_sg, - unsigned int out_sgs, - unsigned int in_sgs, - void *data, - gfp_t gfp) + struct scatterlist *sgs[], + struct vring_packed_desc *desc, + unsigned int total_sg, + unsigned int out_sgs, + unsigned int in_sgs, + void *data, + gfp_t gfp) { - struct vring_packed_desc *desc; struct scatterlist *sg; unsigned int i, n, err_idx; u16 head, id; dma_addr_t addr; head = vq->packed.next_avail_idx; - desc = alloc_indirect_packed(total_sg, gfp); if (unlikely(vq->vq.num_free < 1)) { pr_debug("Can't add buf len 1 - avail = 0\n");
@@ -1191,9 +1190,15 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq, BUG_ON(total_sg == 0); - if (virtqueue_use_indirect(_vq, total_sg)) - return virtqueue_add_indirect_packed(vq, sgs, total_sg, - out_sgs, in_sgs, data, gfp); + if (virtqueue_use_indirect(_vq, total_sg)) { + desc = alloc_indirect_packed(total_sg, gfp); + if (desc) { + return virtqueue_add_indirect_packed(vq, sgs, desc, + total_sg, + out_sgs, in_sgs, + data, gfp); + } + } head = vq->packed.next_avail_idx; avail_used_flags = vq->packed.avail_used_flags;
--
2.31.0
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