From 06e2c4a9eaf2a2ed267b9cee70f91aaf616eb925 Mon Sep 17 00:00:00 2001
From: Bhaumik Bhatt <bbhatt@codeaurora.org>
Date: Mon, 2 Aug 2021 10:42:53 +0530
Subject: [PATCH] bus: mhi: core: Add range checks for BHI and BHIe
Git-commit: 06e2c4a9eaf2a2ed267b9cee70f91aaf616eb925
Patch-mainline: v5.15-rc1
References: bsc#1206451

When obtaining the BHI or BHIe offsets during the power up
preparation phase, range checks are missing. These can help
controller drivers avoid accessing any address outside of the
MMIO region. Ensure that mhi_cntrl->reg_len is set before MHI
registration as it is a required field and range checks will
fail without it.

Link: https://lore.kernel.org/r/1620330705-40192-7-git-send-email-bbhatt@codeaurora.org
Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Reviewed-by: Hemant Kumar <hemantk@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20210802051255.5771-9-manivannan.sadhasivam@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/bus/mhi/core/init.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index 1cc2f225d3d1..aeb1e3c2cdc4 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -885,7 +885,8 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl,
 	if (!mhi_cntrl || !mhi_cntrl->cntrl_dev || !mhi_cntrl->regs ||
 	    !mhi_cntrl->runtime_get || !mhi_cntrl->runtime_put ||
 	    !mhi_cntrl->status_cb || !mhi_cntrl->read_reg ||
-	    !mhi_cntrl->write_reg || !mhi_cntrl->nr_irqs || !mhi_cntrl->irq)
+	    !mhi_cntrl->write_reg || !mhi_cntrl->nr_irqs ||
+	    !mhi_cntrl->irq || !mhi_cntrl->reg_len)
 		return -EINVAL;
 
 	ret = parse_config(mhi_cntrl, config);
@@ -1077,6 +1078,13 @@ int mhi_prepare_for_power_up(struct mhi_controller *mhi_cntrl)
 		dev_err(dev, "Error getting BHI offset\n");
 		goto error_reg_offset;
 	}
+
+	if (bhi_off >= mhi_cntrl->reg_len) {
+		dev_err(dev, "BHI offset: 0x%x is out of range: 0x%zx\n",
+			bhi_off, mhi_cntrl->reg_len);
+		ret = -EINVAL;
+		goto error_reg_offset;
+	}
 	mhi_cntrl->bhi = mhi_cntrl->regs + bhi_off;
 
 	if (mhi_cntrl->fbc_download || mhi_cntrl->rddm_size) {
@@ -1086,6 +1094,14 @@ int mhi_prepare_for_power_up(struct mhi_controller *mhi_cntrl)
 			dev_err(dev, "Error getting BHIE offset\n");
 			goto error_reg_offset;
 		}
+
+		if (bhie_off >= mhi_cntrl->reg_len) {
+			dev_err(dev,
+				"BHIe offset: 0x%x is out of range: 0x%zx\n",
+				bhie_off, mhi_cntrl->reg_len);
+			ret = -EINVAL;
+			goto error_reg_offset;
+		}
 		mhi_cntrl->bhie = mhi_cntrl->regs + bhie_off;
 	}
 
-- 
2.35.3