From: Minwoo Im <minwoo.im.dev@xxxxxxxxx> [ Upstream commit 7e5dd57ef3081ff6c03908d786ed5087f6fbb7ae ] Following condition which will cause NULL pointer dereference will occur in nvme_free_host_mem() when it tries to remove pci device via nvme_remove() especially after a failure of host memory allocation for HMB. "(host_mem_descs == NULL) && (nr_host_mem_descs != 0)" It's because __nr_host_mem_descs__ is not cleared to 0 unlike __host_mem_descs__ is so. Signed-off-by: Minwoo Im <minwoo.im.dev@xxxxxxxxx> Signed-off-by: Christoph Hellwig <hch@xxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> --- drivers/nvme/host/pci.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index 5dae650438c1..cdd2fd509ddc 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -1617,6 +1617,7 @@ static void nvme_free_host_mem(struct nvme_dev *dev) dev->nr_host_mem_descs * sizeof(*dev->host_mem_descs), dev->host_mem_descs, dev->host_mem_descs_dma); dev->host_mem_descs = NULL; + dev->nr_host_mem_descs = 0; } static int __nvme_alloc_host_mem(struct nvme_dev *dev, u64 preferred, -- 2.11.0