From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8B3FB3358D5; Wed, 17 Dec 2025 07:34:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765956858; cv=none; b=VyVYahYdEP9pcuaTOdt77Y1lr1XxMqXd9nvs9ArnJ9pF54U5D5L8M6TllfC31AyfE5PXU4U+nehz16jZWVOgbF05EFr9fWC6GgAMuJIQQJG+3sGzO6ScdMIQ/YMhjjhjAsypPyKPso/hkhzjDOAM/06clpYg3aZvVXK3vLkBxwU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765956858; c=relaxed/simple; bh=QCj3f/NR0mhkrNbwRn7wEBRkVRffQb+7IpIGEpz+0hA=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=tzUiH+MfblhosUQ52XFGqh6nukWNI+tz1x/8rp7KSo426K3KVkTRAr+ydM+NEwRBLUB4ckOLwlFcB81mtzGjGOaXNiN6CPtI2Kp1LFIM+nwRVHC/wC0D7goXUNC3g+zqvG7WIXElwvUQr0YlkD+4Df9yJL+0so2I30xM9uuO23o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=AQbybXgF; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="AQbybXgF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E51A3C4CEF5; Wed, 17 Dec 2025 07:34:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1765956858; bh=QCj3f/NR0mhkrNbwRn7wEBRkVRffQb+7IpIGEpz+0hA=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=AQbybXgFQfqHJxyKElammxi3aGKChh4X8v4rllgwqWW/39Tlt8m4zY+pmegUZmjWT Be/rEU+jarmvxXYqCKphe83NQVvS2lWbs1XqSmKy3Xd9kewajT/qQAIY28ebntyqgJ +7+57WA0fT8MywE5WOtJd3XA5NTf75I3P8IuszgrpRc/PAeqewMt4cFekFzq3oPROd F6WKXzQNfAV1Aj/XBQ2i17ZKJgVoWlqGqfCslz/pel29Ls0TdNi8PmenTc58hOxA0m ohc2AyjFwma46jaiDxtjkoUylprohqyAI2ORIYejpwhQF/5sxNxQh8JLl1MMTW23hq /PiAmB7FgaH6A== Message-ID: <579e05b2-4124-4883-ac97-f7ad294ba635@kernel.org> Date: Wed, 17 Dec 2025 08:34:14 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] nfc: llcp: avoid double release/put on LLCP_CLOSED in nfc_llcp_recv_disc() To: Qianchang Zhao , Paolo Abeni , Jakub Kicinski Cc: "David S. Miller" , Eric Dumazet , Simon Horman , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Zhitong Liu References: <20251217014048.16889-1-pioooooooooip@gmail.com> From: Krzysztof Kozlowski Content-Language: en-US Autocrypt: addr=krzk@kernel.org; keydata= xsFNBFVDQq4BEAC6KeLOfFsAvFMBsrCrJ2bCalhPv5+KQF2PS2+iwZI8BpRZoV+Bd5kWvN79 cFgcqTTuNHjAvxtUG8pQgGTHAObYs6xeYJtjUH0ZX6ndJ33FJYf5V3yXqqjcZ30FgHzJCFUu JMp7PSyMPzpUXfU12yfcRYVEMQrmplNZssmYhiTeVicuOOypWugZKVLGNm0IweVCaZ/DJDIH gNbpvVwjcKYrx85m9cBVEBUGaQP6AT7qlVCkrf50v8bofSIyVa2xmubbAwwFA1oxoOusjPIE J3iadrwpFvsZjF5uHAKS+7wHLoW9hVzOnLbX6ajk5Hf8Pb1m+VH/E8bPBNNYKkfTtypTDUCj NYcd27tjnXfG+SDs/EXNUAIRefCyvaRG7oRYF3Ec+2RgQDRnmmjCjoQNbFrJvJkFHlPeHaeS BosGY+XWKydnmsfY7SSnjAzLUGAFhLd/XDVpb1Een2XucPpKvt9ORF+48gy12FA5GduRLhQU vK4tU7ojoem/G23PcowM1CwPurC8sAVsQb9KmwTGh7rVz3ks3w/zfGBy3+WmLg++C2Wct6nM Pd8/6CBVjEWqD06/RjI2AnjIq5fSEH/BIfXXfC68nMp9BZoy3So4ZsbOlBmtAPvMYX6U8VwD TNeBxJu5Ex0Izf1NV9CzC3nNaFUYOY8KfN01X5SExAoVTr09ewARAQABzSVLcnp5c3p0b2Yg S296bG93c2tpIDxrcnprQGtlcm5lbC5vcmc+wsGVBBMBCgA/AhsDBgsJCAcDAgYVCAIJCgsE FgIDAQIeAQIXgBYhBJvQfg4MUfjVlne3VBuTQ307QWKbBQJoF1BKBQkWlnSaAAoJEBuTQ307 QWKbHukP/3t4tRp/bvDnxJfmNdNVn0gv9ep3L39IntPalBFwRKytqeQkzAju0whYWg+R/rwp +r2I1Fzwt7+PTjsnMFlh1AZxGDmP5MFkzVsMnfX1lGiXhYSOMP97XL6R1QSXxaWOpGNCDaUl ajorB0lJDcC0q3xAdwzRConxYVhlgmTrRiD8oLlSCD5baEAt5Zw17UTNDnDGmZQKR0fqLpWy 786Lm5OScb7DjEgcA2PRm17st4UQ1kF0rQHokVaotxRM74PPDB8bCsunlghJl1DRK9s1aSuN hL1Pv9VD8b4dFNvCo7b4hfAANPU67W40AaaGZ3UAfmw+1MYyo4QuAZGKzaP2ukbdCD/DYnqi tJy88XqWtyb4UQWKNoQqGKzlYXdKsldYqrLHGoMvj1UN9XcRtXHST/IaLn72o7j7/h/Ac5EL 8lSUVIG4TYn59NyxxAXa07Wi6zjVL1U11fTnFmE29ALYQEXKBI3KUO1A3p4sQWzU7uRmbuxn naUmm8RbpMcOfa9JjlXCLmQ5IP7Rr5tYZUCkZz08LIfF8UMXwH7OOEX87Y++EkAB+pzKZNNd hwoXulTAgjSy+OiaLtuCys9VdXLZ3Zy314azaCU3BoWgaMV0eAW/+gprWMXQM1lrlzvwlD/k whyy9wGf0AEPpLssLVt9VVxNjo6BIkt6d1pMg6mHsUEVzsFNBFVDXDQBEADNkrQYSREUL4D3 Gws46JEoZ9HEQOKtkrwjrzlw/tCmqVzERRPvz2Xg8n7+HRCrgqnodIYoUh5WsU84N03KlLue MNsWLJBvBaubYN4JuJIdRr4dS4oyF1/fQAQPHh8Thpiz0SAZFx6iWKB7Qrz3OrGCjTPcW6ei OMheesVS5hxietSmlin+SilmIAPZHx7n242u6kdHOh+/SyLImKn/dh9RzatVpUKbv34eP1wA GldWsRxbf3WP9pFNObSzI/Bo3kA89Xx2rO2roC+Gq4LeHvo7ptzcLcrqaHUAcZ3CgFG88CnA 6z6lBZn0WyewEcPOPdcUB2Q7D/NiUY+HDiV99rAYPJztjeTrBSTnHeSBPb+qn5ZZGQwIdUW9 YegxWKvXXHTwB5eMzo/RB6vffwqcnHDoe0q7VgzRRZJwpi6aMIXLfeWZ5Wrwaw2zldFuO4Dt 91pFzBSOIpeMtfgb/Pfe/a1WJ/GgaIRIBE+NUqckM+3zJHGmVPqJP/h2Iwv6nw8U+7Yyl6gU BLHFTg2hYnLFJI4Xjg+AX1hHFVKmvl3VBHIsBv0oDcsQWXqY+NaFahT0lRPjYtrTa1v3tem/ JoFzZ4B0p27K+qQCF2R96hVvuEyjzBmdq2esyE6zIqftdo4MOJho8uctOiWbwNNq2U9pPWmu 4vXVFBYIGmpyNPYzRm0QPwARAQABwsF8BBgBCgAmAhsMFiEEm9B+DgxR+NWWd7dUG5NDfTtB YpsFAmgXUF8FCRaWWyoACgkQG5NDfTtBYptO0w//dlXJs5/42hAXKsk+PDg3wyEFb4NpyA1v qmx7SfAzk9Hf6lWwU1O6AbqNMbh6PjEwadKUk1m04S7EjdQLsj/MBSgoQtCT3MDmWUUtHZd5 RYIPnPq3WVB47GtuO6/u375tsxhtf7vt95QSYJwCB+ZUgo4T+FV4hquZ4AsRkbgavtIzQisg Dgv76tnEv3YHV8Jn9mi/Bu0FURF+5kpdMfgo1sq6RXNQ//TVf8yFgRtTUdXxW/qHjlYURrm2 H4kutobVEIxiyu6m05q3e9eZB/TaMMNVORx+1kM3j7f0rwtEYUFzY1ygQfpcMDPl7pRYoJjB dSsm0ZuzDaCwaxg2t8hqQJBzJCezTOIkjHUsWAK+tEbU4Z4SnNpCyM3fBqsgYdJxjyC/tWVT AQ18NRLtPw7tK1rdcwCl0GFQHwSwk5pDpz1NH40e6lU+NcXSeiqkDDRkHlftKPV/dV+lQXiu jWt87ecuHlpL3uuQ0ZZNWqHgZoQLXoqC2ZV5KrtKWb/jyiFX/sxSrodALf0zf+tfHv0FZWT2 zHjUqd0t4njD/UOsuIMOQn4Ig0SdivYPfZukb5cdasKJukG1NOpbW7yRNivaCnfZz6dTawXw XRIV/KDsHQiyVxKvN73bThKhONkcX2LWuD928tAR6XMM2G5ovxLe09vuOzzfTWQDsm++9UKF a/A= In-Reply-To: <20251217014048.16889-1-pioooooooooip@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 17/12/2025 02:40, Qianchang Zhao wrote: > nfc_llcp_sock_get() takes a reference on the LLCP socket via sock_hold(). > > In nfc_llcp_recv_disc(), when the socket is already in LLCP_CLOSED state, the > code used to perform release_sock() and nfc_llcp_sock_put() in the CLOSED branch > but then continued execution and later performed the same cleanup again on the > common exit path. This results in refcount imbalance (double put) and unbalanced > lock release. You did not answer to my questions, so I repeat the same question I already asked you. Don't ignore reviewer's feedback. > > Remove the redundant CLOSED-branch cleanup so that release_sock() and > nfc_llcp_sock_put() are performed exactly once via the common exit path, while > keeping the existing DM_DISC reply behavior. > > Reported-by: Qianchang Zhao > Reported-by: Zhitong Liu Drop both. You are the author, there are no reported-by credits for authors. Missing Fixes tag. > Cc: stable@vger.kernel.org > Signed-off-by: Qianchang Zhao > --- > net/nfc/llcp_core.c | 5 ----- > 1 file changed, 5 deletions(-) > > diff --git a/net/nfc/llcp_core.c b/net/nfc/llcp_core.c > index beeb3b4d2..ed37604ed 100644 > --- a/net/nfc/llcp_core.c > +++ b/net/nfc/llcp_core.c > @@ -1177,11 +1177,6 @@ static void nfc_llcp_recv_disc(struct nfc_llcp_local *local, > > nfc_llcp_socket_purge(llcp_sock); > > - if (sk->sk_state == LLCP_CLOSED) { > - release_sock(sk); > - nfc_llcp_sock_put(llcp_sock); So why now sending to closed socket is right? > - } > - > if (sk->sk_state == LLCP_CONNECTED) { > nfc_put_device(local->dev); > sk->sk_state = LLCP_CLOSED; Best regards, Krzysztof