From: Jeffrey Hugo <quic_jhugo@quicinc.com>
Date: Fri, 24 Mar 2023 10:13:04 -0600
Subject: [PATCH] bus: mhi: host: Range check CHDBOFF and ERDBOFF
References: bsc#1012628
Patch-mainline: 6.3.2
Git-commit: 6a0c637bfee69a74c104468544d9f2a6579626d0

commit 6a0c637bfee69a74c104468544d9f2a6579626d0 upstream.

If the value read from the CHDBOFF and ERDBOFF registers is outside the
range of the MHI register space then an invalid address might be computed
which later causes a kernel panic.  Range check the read value to prevent
a crash due to bad data from the device.

Fixes: 6cd330ae76ff ("bus: mhi: core: Add support for ringing channel/event ring doorbells")
Cc: stable@vger.kernel.org
Signed-off-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Reviewed-by: Pranjal Ramajor Asha Kanojiya <quic_pkanojiy@quicinc.com>
Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
Link: https://lore.kernel.org/r/1679674384-27209-1-git-send-email-quic_jhugo@quicinc.com
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 drivers/bus/mhi/host/init.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/bus/mhi/host/init.c b/drivers/bus/mhi/host/init.c
index 3d779ee6..b46a0821 100644
--- a/drivers/bus/mhi/host/init.c
+++ b/drivers/bus/mhi/host/init.c
@@ -516,6 +516,12 @@ int mhi_init_mmio(struct mhi_controller *mhi_cntrl)
 		return -EIO;
 	}
 
+	if (val >= mhi_cntrl->reg_len - (8 * MHI_DEV_WAKE_DB)) {
+		dev_err(dev, "CHDB offset: 0x%x is out of range: 0x%zx\n",
+			val, mhi_cntrl->reg_len - (8 * MHI_DEV_WAKE_DB));
+		return -ERANGE;
+	}
+
 	/* Setup wake db */
 	mhi_cntrl->wake_db = base + val + (8 * MHI_DEV_WAKE_DB);
 	mhi_cntrl->wake_set = false;
@@ -532,6 +538,12 @@ int mhi_init_mmio(struct mhi_controller *mhi_cntrl)
 		return -EIO;
 	}
 
+	if (val >= mhi_cntrl->reg_len - (8 * mhi_cntrl->total_ev_rings)) {
+		dev_err(dev, "ERDB offset: 0x%x is out of range: 0x%zx\n",
+			val, mhi_cntrl->reg_len - (8 * mhi_cntrl->total_ev_rings));
+		return -ERANGE;
+	}
+
 	/* Setup event db address for each ev_ring */
 	mhi_event = mhi_cntrl->mhi_event;
 	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, val += 8, mhi_event++) {
-- 
2.35.3