From: Christoph Hellwig hch@lst.de

stable inclusion from stable-v5.10.231 commit 452f9ddd12bebc04cef741e8ba3806bf0e1fd015 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBEGGM CVE: CVE-2024-56756

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

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[ Upstream commit 3c2fb1ca8086eb139b2a551358137525ae8e0d7a ]

The HMB descriptor table is sized to the maximum number of descriptors that could be used for a given device, but __nvme_alloc_host_mem could break out of the loop earlier on memory allocation failure and end up using less descriptors than planned for, which leads to an incorrect size passed to dma_free_coherent.

In practice this was not showing up because the number of descriptors tends to be low and the dma coherent allocator always allocates and frees at least a page.

Fixes: 87ad72a59a38 ("nvme-pci: implement host memory buffer support") Signed-off-by: Christoph Hellwig hch@lst.de Signed-off-by: Keith Busch kbusch@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yu Kuai yukuai3@huawei.com --- drivers/nvme/host/pci.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index da624c4f2a5f..b397370ba36a 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -147,6 +147,7 @@ struct nvme_dev { /* host memory buffer support: */ u64 host_mem_size; u32 nr_host_mem_descs; + u32 host_mem_descs_size; dma_addr_t host_mem_descs_dma; struct nvme_host_mem_buf_desc *host_mem_descs; void **host_mem_desc_bufs; @@ -1926,10 +1927,10 @@ static void nvme_free_host_mem(struct nvme_dev *dev)

kfree(dev->host_mem_desc_bufs); dev->host_mem_desc_bufs = NULL; - dma_free_coherent(dev->dev, - dev->nr_host_mem_descs * sizeof(*dev->host_mem_descs), + dma_free_coherent(dev->dev, dev->host_mem_descs_size, dev->host_mem_descs, dev->host_mem_descs_dma); dev->host_mem_descs = NULL; + dev->host_mem_descs_size = 0; dev->nr_host_mem_descs = 0; }

@@ -1937,7 +1938,7 @@ static int __nvme_alloc_host_mem(struct nvme_dev *dev, u64 preferred, u32 chunk_size) { struct nvme_host_mem_buf_desc *descs; - u32 max_entries, len; + u32 max_entries, len, descs_size; dma_addr_t descs_dma; int i = 0; void **bufs; @@ -1950,8 +1951,9 @@ static int __nvme_alloc_host_mem(struct nvme_dev *dev, u64 preferred, if (dev->ctrl.hmmaxd && dev->ctrl.hmmaxd < max_entries) max_entries = dev->ctrl.hmmaxd;

- descs = dma_alloc_coherent(dev->dev, max_entries * sizeof(*descs), - &descs_dma, GFP_KERNEL); + descs_size = max_entries * sizeof(*descs); + descs = dma_alloc_coherent(dev->dev, descs_size, &descs_dma, + GFP_KERNEL); if (!descs) goto out;

@@ -1980,6 +1982,7 @@ static int __nvme_alloc_host_mem(struct nvme_dev *dev, u64 preferred, dev->host_mem_size = size; dev->host_mem_descs = descs; dev->host_mem_descs_dma = descs_dma; + dev->host_mem_descs_size = descs_size; dev->host_mem_desc_bufs = bufs; return 0;

@@ -1994,8 +1997,7 @@ static int __nvme_alloc_host_mem(struct nvme_dev *dev, u64 preferred,

kfree(bufs); out_free_descs: - dma_free_coherent(dev->dev, max_entries * sizeof(*descs), descs, - descs_dma); + dma_free_coherent(dev->dev, descs_size, descs, descs_dma); out: dev->host_mem_descs = NULL; return -ENOMEM;