CVE-2024-42283 Information

Description

In the Linux kernel the following vulnerability has been resolved:

net: nexthop: Initialize all fields in dumped nexthops

struct nexthop_grp contains two reserved fields that are not initialized by nla_put_nh_group() and carry garbage. This can be observed e.g. with strace (edited for clarity):

 ip nexthop add id 1 dev lo
 ip nexthop add id 101 group 1
 strace -e recvmsg ip nexthop get id 101
...
recvmsg(... [nla_len=12 nla_type=NHA_GROUP
             [id=1 weight=0 resvd1=0x69 resvd2=0x67]] ...) = 52

The fields are reserved and therefore not currently used. But as they are they leak kernel memory and the fact they are not just zero complicates repurposing of the fields for new ends. Initialize the full structure.

Reference

https://git.kernel.org/stable/c/1377de719652d868f5317ba8398b7e74c5f0430b https://git.kernel.org/stable/c/7704460acd7f5d35eb07c52500987dc9b95313fb https://git.kernel.org/stable/c/a13d3864b76ac87085ec530b2ff8e37482a63a96 https://git.kernel.org/stable/c/6d745cd0e9720282cd291d36b9db528aea18add2