From: Jakub Kicinski <kuba@kernel.org>
To: Kees Cook <keescook@chromium.org>
Cc: "David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Paolo Abeni <pabeni@redhat.com>,
Pablo Neira Ayuso <pablo@netfilter.org>,
Jozsef Kadlecsik <kadlec@netfilter.org>,
Florian Westphal <fw@strlen.de>,
syzbot <syzkaller@googlegroups.com>,
Yajun Deng <yajun.deng@linux.dev>,
netdev@vger.kernel.org, netfilter-devel@vger.kernel.org,
coreteam@netfilter.org, Oliver Hartkopp <socketcan@hartkopp.net>,
Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>,
linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: Re: [PATCH 1/2] netlink: Bounds-check nlmsg_len()
Date: Thu, 1 Sep 2022 12:49:15 -0700 [thread overview]
Message-ID: <20220901124915.24ebc067@kernel.org> (raw)
In-Reply-To: <202208312324.F2F8B28CA@keescook>
On Wed, 31 Aug 2022 23:27:08 -0700 Kees Cook wrote:
> This would catch corrupted values...
>
> Is the concern the growth in image size? The check_sub_overflow() isn't
> large at all -- it's just adding a single overflow bit test. The WARNs
> are heavier, but they're all out-of-line.
It turns the most obvious function into a noodle bar :(
Looking at this function in particular is quite useful, because
it clearly indicates that the nlmsg_len includes the header.
How about we throw in a
WARN_ON_ONCE(nlh->nlmsg_len < NLMSG_HDRLEN ||
nlh->nlmsg_len > INT_MAX);
but leave the actual calculation human readable C?
next prev parent reply other threads:[~2022-09-01 19:49 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-01 3:06 [PATCH 0/2] netlink: Bounds-check struct nlmsgerr creation Kees Cook
2022-09-01 3:06 ` [PATCH 1/2] netlink: Bounds-check nlmsg_len() Kees Cook
2022-09-01 3:18 ` Jakub Kicinski
2022-09-01 6:27 ` Kees Cook
2022-09-01 19:49 ` Jakub Kicinski [this message]
2022-09-01 20:54 ` Eric Dumazet
2022-09-01 3:06 ` [PATCH 2/2] netlink: Bounds-check struct nlmsgerr creation Kees Cook
2022-09-01 3:20 ` Jakub Kicinski
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