[PATCH 4.14 073/237] net/wan/fsl_ucc_hdlc: reject muram offsets above 64K

Greg Kroah-Hartman
2020-02-27T14:38:43Z

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 571a1ff8f81f2..6a26cef621935 100644
--- a/drivers/net/wan/fsl_ucc_hdlc.c
+++ b/drivers/net/wan/fsl_ucc_hdlc.c
@@ -240,6 +240,11 @@ 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