From: Daniel Borkmann <daniel@iogearbox.net>
To: Arnd Bergmann <arnd@arndb.de>, Alexei Starovoitov <ast@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>,
Edward Cree <ecree@solarflare.com>,
John Fastabend <john.fastabend@gmail.com>,
Jakub Kicinski <jakub.kicinski@netronome.com>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] [net-next] bpf: fix out-of-bounds access warning in bpf_check
Date: Thu, 02 Nov 2017 23:35:22 +0100 [thread overview]
Message-ID: <59FB9DAA.702@iogearbox.net> (raw)
In-Reply-To: <20171102110558.2746221-2-arnd@arndb.de>
On 11/02/2017 12:05 PM, Arnd Bergmann wrote:
> The bpf_verifer_ops array is generated dynamically and may be
> empty depending on configuration, which then causes an out
> of bounds access:
>
> kernel/bpf/verifier.c: In function 'bpf_check':
> kernel/bpf/verifier.c:4320:29: error: array subscript is above array bounds [-Werror=array-bounds]
>
> This adds a check to the start of the function as a workaround.
> I would assume that the function is never called in that configuration,
> so the warning is probably harmless.
>
> Fixes: 00176a34d9e2 ("bpf: remove the verifier ops from program structure")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
LGTM, and bpf_analyzer() already has proper logic to bail out for
such cases (although only used by nfp right now, which is there
when NET is configured anyway).
next prev parent reply other threads:[~2017-11-02 22:35 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-02 11:05 [PATCH 1/2] [net-next] bpf: fix link error without CONFIG_NET Arnd Bergmann
2017-11-02 11:05 ` [PATCH 2/2] [net-next] bpf: fix out-of-bounds access warning in bpf_check Arnd Bergmann
2017-11-02 15:59 ` Alexei Starovoitov
2017-11-02 16:14 ` Arnd Bergmann
2017-11-02 17:58 ` Jakub Kicinski
2017-11-02 18:47 ` Alexei Starovoitov
2017-11-02 22:35 ` Daniel Borkmann [this message]
2017-11-03 5:20 ` David Miller
2017-11-02 17:55 ` [PATCH 1/2] [net-next] bpf: fix link error without CONFIG_NET Jakub Kicinski
2017-11-02 18:48 ` Alexei Starovoitov
2017-11-02 22:32 ` Daniel Borkmann
2017-11-03 5:20 ` David Miller
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