From: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
To: Jeremy Cline <jeremy@jcline.org>
Cc: "David S . Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
syzbot+0839b78e119aae1fec78@syzkaller.appspotmail.com,
Hillf Danton <hdanton@sina.com>
Subject: Re: [PATCH] nfc: nci: assert requested protocol is valid
Date: Thu, 7 Sep 2023 08:24:17 +0200 [thread overview]
Message-ID: <ccf7072c-cebb-0491-f07e-8c781a2f4664@linaro.org> (raw)
In-Reply-To: <20230906233347.823171-1-jeremy@jcline.org>
On 07/09/2023 01:33, Jeremy Cline wrote:
> The protocol is used in a bit mask to determine if the protocol is
> supported. Assert the provided protocol is less than the maximum
> defined so it doesn't potentially perform a shift-out-of-bounds and
> provide a clearer error for undefined protocols vs unsupported ones.
>
> Fixes: 6a2968aaf50c ("NFC: basic NCI protocol implementation")
> Reported-and-tested-by: syzbot+0839b78e119aae1fec78@syzkaller.appspotmail.com
> Closes: https://syzkaller.appspot.com/bug?extid=0839b78e119aae1fec78
> Signed-off-by: Jeremy Cline <jeremy@jcline.org>
> ---
> net/nfc/nci/core.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/net/nfc/nci/core.c b/net/nfc/nci/core.c
> index fff755dde30d..6c9592d05120 100644
> --- a/net/nfc/nci/core.c
> +++ b/net/nfc/nci/core.c
> @@ -909,6 +909,11 @@ static int nci_activate_target(struct nfc_dev *nfc_dev,
> return -EINVAL;
> }
>
> + if (protocol >= NFC_PROTO_MAX) {
> + pr_err("the requested nfc protocol is invalid\n");
> + return -EINVAL;
> + }
This looks OK, but I wonder if protocol 0 (so BIT(0) in the
supported_protocols) is a valid protocol. I looked at the code and it
was nowhere handled.
Original patch from Hilf Danton was also handling it (I wonder why Hilf
did not send his patch...)
https://syzkaller.appspot.com/bug?extid=0839b78e119aae1fec78
Best regards,
Krzysztof
next prev parent reply other threads:[~2023-09-07 16:38 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-06 23:33 [PATCH] nfc: nci: assert requested protocol is valid Jeremy Cline
2023-09-07 6:24 ` Krzysztof Kozlowski [this message]
2023-09-07 12:41 ` Jeremy Cline
2023-09-07 14:41 ` Simon Horman
2023-09-08 1:01 ` Jeremy Cline
2023-10-09 20:00 ` [PATCH v2 net] " Jeremy Cline
2023-10-11 15:37 ` Simon Horman
2023-10-12 7:40 ` patchwork-bot+netdevbpf
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