6.12-stable review patch. If anyone has any objections, please let me know.
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From: Keith Busch kbusch@kernel.org
[ Upstream commit 6fad84a4d624c300d03ebba457cc641765050c43 ]
If the device supports SGLs, use these for all user requests. This format encodes the expected transfer length so it can catch short buffer errors in a user command, whether it occurred accidently or maliciously.
For controllers that support SGL data mode, this is a viable mitigation to CVE-2023-6238. For controllers that don't support SGLs, log a warning in the passthrough path since not having the capability can corrupt data if the interface is not used correctly.
Reviewed-by: Christoph Hellwig hch@lst.de Signed-off-by: Keith Busch kbusch@kernel.org Stable-dep-of: 00817f0f1c45 ("nvme-ioctl: fix leaked requests on mapping error") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/nvme/host/ioctl.c | 12 ++++++++++-- drivers/nvme/host/pci.c | 5 +++-- 2 files changed, 13 insertions(+), 4 deletions(-)
diff --git a/drivers/nvme/host/ioctl.c b/drivers/nvme/host/ioctl.c index 61af1583356c2..d4b80938de09c 100644 --- a/drivers/nvme/host/ioctl.c +++ b/drivers/nvme/host/ioctl.c @@ -120,12 +120,20 @@ static int nvme_map_user_request(struct request *req, u64 ubuffer, struct nvme_ns *ns = q->queuedata; struct block_device *bdev = ns ? ns->disk->part0 : NULL; bool supports_metadata = bdev && blk_get_integrity(bdev->bd_disk); + struct nvme_ctrl *ctrl = nvme_req(req)->ctrl; bool has_metadata = meta_buffer && meta_len; struct bio *bio = NULL; int ret;
- if (has_metadata && !supports_metadata) - return -EINVAL; + if (!nvme_ctrl_sgl_supported(ctrl)) + dev_warn_once(ctrl->device, "using unchecked data buffer\n"); + if (has_metadata) { + if (!supports_metadata) + return -EINVAL; + if (!nvme_ctrl_meta_sgl_supported(ctrl)) + dev_warn_once(ctrl->device, + "using unchecked metadata buffer\n"); + }
if (ioucmd && (ioucmd->flags & IORING_URING_CMD_FIXED)) { struct iov_iter iter; diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index 58bdd0da6b658..e1329d4974fd6 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -514,7 +514,8 @@ static inline bool nvme_pci_metadata_use_sgls(struct nvme_dev *dev, { if (!nvme_ctrl_meta_sgl_supported(&dev->ctrl)) return false; - return req->nr_integrity_segments > 1; + return req->nr_integrity_segments > 1 || + nvme_req(req)->flags & NVME_REQ_USERCMD; }
static inline bool nvme_pci_use_sgls(struct nvme_dev *dev, struct request *req, @@ -532,7 +533,7 @@ static inline bool nvme_pci_use_sgls(struct nvme_dev *dev, struct request *req, if (nvme_pci_metadata_use_sgls(dev, req)) return true; if (!sgl_threshold || avg_seg_size < sgl_threshold) - return false; + return nvme_req(req)->flags & NVME_REQ_USERCMD; return true; }