[PATCH 4.14 61/77] power: supply: cpcap-battery: Fix division by zero

Greg Kroah-Hartman
2019-05-23T19:13:58Z

[ Upstream commit dbe7208c6c4aec083571f2ec742870a0d0edbea3 ]

If called fast enough so samples do not increment, we can get
division by zero in kernel:

__div0
cpcap_battery_cc_raw_div
cpcap_battery_get_property
power_supply_get_property.part.1
power_supply_get_property
power_supply_show_property
power_supply_uevent

Fixes: 874b2adbed12 ("power: supply: cpcap-battery: Add a battery driver")
Signed-off-by: Tony Lindgren <tony@atomide.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/power/supply/cpcap-battery.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/power/supply/cpcap-battery.c b/drivers/power/supply/cpcap-battery.c
index ee71a2b37b12c..fe7fcf3a2ad03 100644
--- a/drivers/power/supply/cpcap-battery.c
+++ b/drivers/power/supply/cpcap-battery.c
@@ -221,6 +221,9 @@ static int cpcap_battery_cc_raw_div(struct cpcap_battery_ddata *ddata,
int avg_current;
u32 cc_lsb;

+ if (!divider)
+ return 0;
+
sample &= 0xffffff; /* 24-bits, unsigned */
offset &= 0x7ff; /* 10-bits, signed */

--
2.20.1