Re: [PATCH net-next] bonding: don't cast const buf in sysfs store

[David Miller]

From: Nikolay Aleksandrov 
Date: Sun, 22 Jul 2018 11:37:31 +0300

> As was recently discussed [1], let's avoid casting the const buf in
> bonding_sysfs_store_option and use kstrndup/kfree instead.
> 
> [1] http://lists.openwall.net/netdev/2018/07/22/25
> 
> Signed-off-by: Nikolay Aleksandrov 

Applied, thanks Nikolay.

[PATCH net-next] bonding: don't cast const buf in sysfs store

[Nikolay Aleksandrov]

As was recently discussed [1], let's avoid casting the const buf in
bonding_sysfs_store_option and use kstrndup/kfree instead.

[1] http://lists.openwall.net/netdev/2018/07/22/25

Signed-off-by: Nikolay Aleksandrov 
---
 drivers/net/bonding/bond_sysfs.c | 7 ++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c
index 6096440e96ea..35847250da5a 100644
--- a/drivers/net/bonding/bond_sysfs.c
+++ b/drivers/net/bonding/bond_sysfs.c
@@ -160,14 +160,19 @@ static ssize_t bonding_sysfs_store_option(struct device 
*d,
 {
struct bonding *bond = to_bond(d);
const struct bond_option *opt;
+   char *buffer_clone;
int ret;
 
opt = bond_opt_get_by_name(attr->attr.name);
if (WARN_ON(!opt))
return -ENOENT;
-   ret = bond_opt_tryset_rtnl(bond, opt->id, (char *)buffer);
+   buffer_clone = kstrndup(buffer, count, GFP_KERNEL);
+   if (!buffer_clone)
+   return -ENOMEM;
+   ret = bond_opt_tryset_rtnl(bond, opt->id, buffer_clone);
if (!ret)
ret = count;
+   kfree(buffer_clone);
 
return ret;
 }
-- 
2.11.0