[PATCH] OPP: of: Fix potential multiplication overflow when calculating freq

Colin Ian King <[email protected]>
Newsgroups org.kernel.vger.linux-pm,org.kernel.vger.kernel-janitors,org.kernel.vger.linux-kernel
Message-ID <[email protected]>
The multiplication be32_to_cpup(val++) * 1000 is performed using 32 bit
unsigned integers and hence uses a 32 bit multiplication; this will
overflow if be32_to_cpup(val++) is greater than 4294967 (which is
very unlikely at present). The result is assigned to an unsigned long
(which is a 64 bit value on 64 bit systems), so fix this potential
overflow by casting the first operand of the multiplication to
an unsigned int.

Fixes: b496dfbc94ab ("PM / OPP: Initialize OPP table from device tree")

Signed-off-by: Colin Ian King <[email protected]>
---
 drivers/opp/of.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/opp/of.c b/drivers/opp/of.c
index c02e20632fa6..9c4fd1f0e944 100644
--- a/drivers/opp/of.c
+++ b/drivers/opp/of.c
@@ -1039,7 +1039,7 @@ static int _of_add_opp_table_v1(struct device *dev, struct opp_table *opp_table)
 
 	val = prop->value;
 	while (nr) {
-		unsigned long freq = be32_to_cpup(val++) * 1000;
+		unsigned long freq = (unsigned long)be32_to_cpup(val++) * 1000;
 		unsigned long volt = be32_to_cpup(val++);
 		struct dev_pm_opp_data data = {
 			.freq = freq,
-- 
2.55.0
lmpx.com only provides a reader for public news (NNTP) servers. It is not affiliated with the servers or forums shown here and is not responsible for the content of articles, which is written by their respective authors.