nvme: Add error check for xa_store in nvme_get_effects_log

The xa_store() may fail due to memory allocation failure because there
is no guarantee that the index csi is already used. This fix adds an
error check of the return value of xa_store() in nvme_get_effects_log().

Fixes: 1cf7a12 ("nvme: use an xarray to lookup the Commands Supported and Effects log")
Signed-off-by: Keisuke Nishimura <keisuke.nishimura@inria.fr>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>

drivers/nvme/host/core.c

@@ -3092,7 +3092,7 @@ int nvme_get_log(struct nvme_ctrl *ctrl, u32 nsid, u8 log_page, u8 lsp, u8 csi,
 static int nvme_get_effects_log(struct nvme_ctrl *ctrl, u8 csi,
 				struct nvme_effects_log **log)
 {
-	struct nvme_effects_log	*cel = xa_load(&ctrl->cels, csi);
+	struct nvme_effects_log *old, *cel = xa_load(&ctrl->cels, csi);
 	int ret;
 
 	if (cel)
@@ -3109,7 +3109,11 @@ static int nvme_get_effects_log(struct nvme_ctrl *ctrl, u8 csi,
 		return ret;
 	}
 
-	xa_store(&ctrl->cels, csi, cel, GFP_KERNEL);
+	old = xa_store(&ctrl->cels, csi, cel, GFP_KERNEL);
+	if (xa_is_err(old)) {
+		kfree(cel);
+		return xa_err(old);
+	}
 out:
 	*log = cel;
 	return 0;