[PATCH AUTOSEL 5.5 514/542] nvmet: fix dsm failure when payload does not match sgl descriptor

[Sasha Levin]

From: Sagi Grimberg <sagi@xxxxxxxxxxx>

[ Upstream commit b716e6889c95f64ba32af492461f6cc9341f3f05 ]

The host is allowed to pass the controller an sgl describing a buffer
that is larger than the dsm payload itself, allow it when executing
dsm.

Reported-by: Dakshaja Uppalapati <dakshaja@xxxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>,
Reviewed-by: Max Gurtovoy <maxg@xxxxxxxxxxxx>
Signed-off-by: Sagi Grimberg <sagi@xxxxxxxxxxx>
Signed-off-by: Keith Busch <kbusch@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/nvme/target/core.c        | 11 +++++++++++
 drivers/nvme/target/io-cmd-bdev.c |  2 +-
 drivers/nvme/target/io-cmd-file.c |  2 +-
 drivers/nvme/target/nvmet.h       |  1 +
 4 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index 35810a0a8d212..461987f669c50 100644
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c
@@ -939,6 +939,17 @@ bool nvmet_check_data_len(struct nvmet_req *req, size_t data_len)
 }
 EXPORT_SYMBOL_GPL(nvmet_check_data_len);
 
+bool nvmet_check_data_len_lte(struct nvmet_req *req, size_t data_len)
+{
+	if (unlikely(data_len > req->transfer_len)) {
+		req->error_loc = offsetof(struct nvme_common_command, dptr);
+		nvmet_req_complete(req, NVME_SC_SGL_INVALID_DATA | NVME_SC_DNR);
+		return false;
+	}
+
+	return true;
+}
+
 int nvmet_req_alloc_sgl(struct nvmet_req *req)
 {
 	struct pci_dev *p2p_dev = NULL;
diff --git a/drivers/nvme/target/io-cmd-bdev.c b/drivers/nvme/target/io-cmd-bdev.c
index b6fca0e421ef1..ea0e596be15dc 100644
--- a/drivers/nvme/target/io-cmd-bdev.c
+++ b/drivers/nvme/target/io-cmd-bdev.c
@@ -280,7 +280,7 @@ static void nvmet_bdev_execute_discard(struct nvmet_req *req)
 
 static void nvmet_bdev_execute_dsm(struct nvmet_req *req)
 {
-	if (!nvmet_check_data_len(req, nvmet_dsm_len(req)))
+	if (!nvmet_check_data_len_lte(req, nvmet_dsm_len(req)))
 		return;
 
 	switch (le32_to_cpu(req->cmd->dsm.attributes)) {
diff --git a/drivers/nvme/target/io-cmd-file.c b/drivers/nvme/target/io-cmd-file.c
index caebfce066056..cd5670b83118f 100644
--- a/drivers/nvme/target/io-cmd-file.c
+++ b/drivers/nvme/target/io-cmd-file.c
@@ -336,7 +336,7 @@ static void nvmet_file_dsm_work(struct work_struct *w)
 
 static void nvmet_file_execute_dsm(struct nvmet_req *req)
 {
-	if (!nvmet_check_data_len(req, nvmet_dsm_len(req)))
+	if (!nvmet_check_data_len_lte(req, nvmet_dsm_len(req)))
 		return;
 	INIT_WORK(&req->f.work, nvmet_file_dsm_work);
 	schedule_work(&req->f.work);
diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
index 46df45e837c95..eda28b22a2c87 100644
--- a/drivers/nvme/target/nvmet.h
+++ b/drivers/nvme/target/nvmet.h
@@ -374,6 +374,7 @@ bool nvmet_req_init(struct nvmet_req *req, struct nvmet_cq *cq,
 		struct nvmet_sq *sq, const struct nvmet_fabrics_ops *ops);
 void nvmet_req_uninit(struct nvmet_req *req);
 bool nvmet_check_data_len(struct nvmet_req *req, size_t data_len);
+bool nvmet_check_data_len_lte(struct nvmet_req *req, size_t data_len);
 void nvmet_req_complete(struct nvmet_req *req, u16 status);
 int nvmet_req_alloc_sgl(struct nvmet_req *req);
 void nvmet_req_free_sgl(struct nvmet_req *req);
-- 
2.20.1