lkml.org 
[lkml]   [2019]   [Jul]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] hwmon (occ): Fix division by zero issue
Date
The code in occ_get_powr_avg() invokes div64_u64() without checking the
divisor. In case the divisor is zero, kernel gets an "Division by zero
in kernel" error.

Check the divisor and make it return 0 if the divisor is 0.

Signed-off-by: Lei YU <mine260309@gmail.com>
Reviewed-by: Eddie James <eajames@linux.ibm.com>
---
drivers/hwmon/occ/common.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/hwmon/occ/common.c b/drivers/hwmon/occ/common.c
index 13a6290..f02aa40 100644
--- a/drivers/hwmon/occ/common.c
+++ b/drivers/hwmon/occ/common.c
@@ -402,8 +402,10 @@ static ssize_t occ_show_power_1(struct device *dev,

static u64 occ_get_powr_avg(u64 *accum, u32 *samples)
{
- return div64_u64(get_unaligned_be64(accum) * 1000000ULL,
- get_unaligned_be32(samples));
+ u64 divisor = get_unaligned_be32(samples);
+
+ return (divisor == 0) ? 0 :
+ div64_u64(get_unaligned_be64(accum) * 1000000ULL, divisor);
}

static ssize_t occ_show_power_2(struct device *dev,
--
2.7.4
\
 
 \ /
  Last update: 2019-07-11 04:46    [W:0.077 / U:0.708 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site