From 6123f1fe53985645992b2ff648b3087b77b3ed16 Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Wed, 21 Aug 2019 10:11:22 +0300
Subject: [PATCH] misc: xilinx_sdfec: Prevent integer overflow in
xsdfec_table_write()
The checking here needs to handle integer overflows because "offset" and
"len" come from the user.
Fixes: 20ec628e8007 ("misc: xilinx_sdfec: Add ability to configure LDPC")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Dragan Cvetic <dragan.cvetic@xilinx.com>
Link: https://lore.kernel.org/r/20190821071122.GD26957@mwanda
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/misc/xilinx_sdfec.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/misc/xilinx_sdfec.c b/drivers/misc/xilinx_sdfec.c
index 3fc53d20abf3..0bf3bcc8e1ef 100644
--- a/drivers/misc/xilinx_sdfec.c
+++ b/drivers/misc/xilinx_sdfec.c
@@ -611,7 +611,9 @@ static int xsdfec_table_write(struct xsdfec_dev *xsdfec, u32 offset,
* Writes that go beyond the length of
* Shared Scale(SC) table should fail
*/
- if ((XSDFEC_REG_WIDTH_JUMP * (offset + len)) > depth) {
+ if (offset > depth / XSDFEC_REG_WIDTH_JUMP ||
+ len > depth / XSDFEC_REG_WIDTH_JUMP ||
+ offset + len > depth / XSDFEC_REG_WIDTH_JUMP) {
dev_dbg(xsdfec->dev, "Write exceeds SC table length");
return -EINVAL;
}
--
2.30.9