linux-kernel - Re: [PATCH] net: sched: Fix memory exposure from short TCA_U32

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Sun, 26 Aug 2018 14:22:52 -0700 (PDT)
From:   David Miller <davem@...emloft.net>
To:     keescook@...omium.org
Cc:     linux-kernel@...r.kernel.org, viro@...iv.linux.org.uk,
        jhs@...atatu.com, xiyou.wangcong@...il.com, jiri@...nulli.us,
        netdev@...r.kernel.org
Subject: Re: [PATCH] net: sched: Fix memory exposure from short TCA_U32_SEL

From: Kees Cook <keescook@...omium.org>
Date: Sat, 25 Aug 2018 22:58:01 -0700

> Via u32_change(), TCA_U32_SEL has an unspecified type in the netlink
> policy, so max length isn't enforced, only minimum. This means nkeys
> (from userspace) was being trusted without checking the actual size of
> nla_len(), which could lead to a memory over-read, and ultimately an
> exposure via a call to u32_dump(). Reachability is CAP_NET_ADMIN within
> a namespace.
> 
> Reported-by: Al Viro <viro@...iv.linux.org.uk>
> Signed-off-by: Kees Cook <keescook@...omium.org>

I'll apply this as-is and queued it up for -stable.

If we want to avoid sizeof(*p) type stuff, it can be done as a follow-up.

Thanks.