From: Levin, Alexander <alexander.levin@verizon.com>
Date: Tue, 18 Jul 2017 04:23:16 +0000 (+0000)
Subject: wireless: wext: terminate ifr name coming from userspace
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=98de4e0ea47d106846fc0e30ce4e644283fa7fc2;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

wireless: wext: terminate ifr name coming from userspace

ifr name is assumed to be a valid string by the kernel, but nothing
was forcing username to pass a valid string.

In turn, this would cause panics as we tried to access the string
past it's valid memory.

Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/core/dev_ioctl.c b/net/core/dev_ioctl.c
index 82fd4c9c4a1b..7657ad6bc13d 100644
--- a/net/core/dev_ioctl.c
+++ b/net/core/dev_ioctl.c
@@ -424,6 +424,8 @@ int dev_ioctl(struct net *net, unsigned int cmd, void __user *arg)
 		if (copy_from_user(&iwr, arg, sizeof(iwr)))
 			return -EFAULT;
 
+		iwr.ifr_name[sizeof(iwr.ifr_name) - 1] = 0;
+
 		return wext_handle_ioctl(net, &iwr, cmd, arg);
 	}