From: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
To: Siddh Raman Pant <code@siddh.me>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/4] nfc: Extract nfc_dev access from nfc_alloc_send_skb() into the callers
Date: Mon, 27 Nov 2023 11:10:51 +0100 [thread overview]
Message-ID: <ae2aae77-c194-4924-b698-4a499eabec5d@linaro.org> (raw)
In-Reply-To: <ba18da37e48b5c473e5b8bd76d6460017342f968.1700943019.git.code@siddh.me>
On 25/11/2023 21:26, Siddh Raman Pant wrote:
> The only reason why nfc_dev was accessed inside nfc_alloc_send_skb() is
> for getting the headroom and tailroom values.
>
> This can cause UAF to be reported from nfc_alloc_send_skb(), but the
> callers are responsible for managing the device access, and thus the
> UAF being reported, as the callers (like nfc_llcp_send_ui_frame()) may
> repeatedly call this function, and this function will repeatedly try
> to get the same headroom and tailroom values.
I don't understand this sentence.
"This can cause ..., but ...". But starts another clause which should be
in contradictory to previous one.
>
> Thus, put the nfc_dev access responsibility on the callers and accept
> the headroom and tailroom values directly.
Is this a fix or improvement? If fix, is the UAF real? If so, you miss
Fixes tag.
Best regards,
Krzysztof
next prev parent reply other threads:[~2023-11-27 10:10 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-25 20:26 [PATCH 0/4] Fix UAF caused by racing datagram sending and freeing of nfc_dev Siddh Raman Pant
2023-11-25 20:26 ` [PATCH 1/4] nfc: Extract nfc_dev access from nfc_alloc_send_skb() into the callers Siddh Raman Pant
2023-11-27 10:10 ` Krzysztof Kozlowski [this message]
2023-12-02 13:31 ` Siddh Raman Pant
2023-11-25 20:26 ` [PATCH 2/4] nfc: Protect access to nfc_dev in an llcp_sock with a rwlock Siddh Raman Pant
2023-11-27 10:38 ` Krzysztof Kozlowski
2023-12-02 13:30 ` Siddh Raman Pant
2023-11-25 20:26 ` [PATCH 3/4] nfc: Do not send datagram if socket state isn't LLCP_BOUND Siddh Raman Pant
2023-11-27 10:54 ` Krzysztof Kozlowski
2023-11-25 20:26 ` [PATCH 4/4] nfc: llcp_sock_sendmsg: Reformat code to make the smaller block indented Siddh Raman Pant
2023-11-27 10:57 ` Krzysztof Kozlowski
2023-11-27 10:04 ` [PATCH 0/4] Fix UAF caused by racing datagram sending and freeing of nfc_dev Krzysztof Kozlowski
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