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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Qiang Zhao <qiang.zhao@nxp.com>,
        Timur Tabi <timur@kernel.org>,
        Rasmus Villemoes <linux@rasmusvillemoes.dk>,
        "David S. Miller" <davem@davemloft.net>,
        Li Yang <leoyang.li@nxp.com>, Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.5 116/399] net/wan/fsl_ucc_hdlc: reject muram offsets above 64K
Date:   Fri, 21 Feb 2020 08:37:21 +0100
Message-Id: <20200221072413.730008002@linuxfoundation.org>
In-Reply-To: <20200221072402.315346745@linuxfoundation.org>
References: <20200221072402.315346745@linuxfoundation.org>
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From: Rasmus Villemoes <linux@rasmusvillemoes.dk>

[ Upstream commit 148587a59f6b85831695e0497d9dd1af5f0495af ]

Qiang Zhao points out that these offsets get written to 16-bit
registers, and there are some QE platforms with more than 64K
muram. So it is possible that qe_muram_alloc() gives us an allocation
that can't actually be used by the hardware, so detect and reject
that.

Reported-by: Qiang Zhao <qiang.zhao@nxp.com>
Reviewed-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Li Yang <leoyang.li@nxp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/wan/fsl_ucc_hdlc.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/net/wan/fsl_ucc_hdlc.c b/drivers/net/wan/fsl_ucc_hdlc.c
index aef7de225783f..4ad0a0c33d853 100644
--- a/drivers/net/wan/fsl_ucc_hdlc.c
+++ b/drivers/net/wan/fsl_ucc_hdlc.c
@@ -245,6 +245,11 @@ static int uhdlc_init(struct ucc_hdlc_private *priv)
 		ret = -ENOMEM;
 		goto free_riptr;
 	}
+	if (riptr != (u16)riptr || tiptr != (u16)tiptr) {
+		dev_err(priv->dev, "MURAM allocation out of addressable range\n");
+		ret = -ENOMEM;
+		goto free_tiptr;
+	}
 
 	/* Set RIPTR, TIPTR */
 	iowrite16be(riptr, &priv->ucc_pram->riptr);
-- 
2.20.1