From: Yonghong Song <yhs@fb.com>
To: Daniel Borkmann <daniel@iogearbox.net>,
"alexei.starovoitov@gmail.com" <alexei.starovoitov@gmail.com>
Cc: "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
"bpf@vger.kernel.org" <bpf@vger.kernel.org>
Subject: Re: [PATCH bpf] bpf: fix missing prog untrack in release_maps
Date: Mon, 16 Dec 2019 18:52:02 +0000 [thread overview]
Message-ID: <31a08a1a-a6cb-d216-c954-e06abd230000@fb.com> (raw)
In-Reply-To: <1c2909484ca524ae9f55109b06f22b6213e76376.1576514756.git.daniel@iogearbox.net>
On 12/16/19 8:49 AM, Daniel Borkmann wrote:
> Commit da765a2f5993 ("bpf: Add poke dependency tracking for prog array
> maps") wrongly assumed that in case of prog load errors, we're cleaning
> up all program tracking via bpf_free_used_maps().
>
> However, it can happen that we're still at the point where we didn't copy
> map pointers into the prog's aux section such that env->prog->aux->used_maps
> is still zero, running into a UAF. In such case, the verifier has similar
> release_maps() helper that drops references to used maps from its env.
>
> Consolidate the release code into __bpf_free_used_maps() and call it from
> all sides to fix it.
>
> Fixes: da765a2f5993 ("bpf: Add poke dependency tracking for prog array maps")
> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
next prev parent reply other threads:[~2019-12-16 18:52 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-16 16:49 [PATCH bpf] bpf: fix missing prog untrack in release_maps Daniel Borkmann
2019-12-16 18:52 ` Yonghong Song [this message]
2019-12-16 20:33 ` Alexei Starovoitov
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