From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx12.kaspersky-labs.com (mx12.kaspersky-labs.com [91.103.66.155]) (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 6D5CC2F2900; Fri, 21 Nov 2025 13:07:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.103.66.155 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763730464; cv=none; b=psZhPD3thgSQbQymcm41kQgqCLZNfIAxlpswbhej5vJnTfsGxb897rgHGkKZ4+wkN5boOuOBMJl9GAhMhEks8QM/PO2eHCGrvR1chkhSZPKdPUvSyDcd6az4+zTFLolGUBDZkVvWmO2WbxYdPyj0yuzSU70c67CZ7FVuJUYXy3o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763730464; c=relaxed/simple; bh=XSWFcLzFNcH7IwA2R3+9HEqRUYncMcqCIwvE/4AErvU=; h=From:To:CC:Subject:Date:Message-ID:References:In-Reply-To: Content-Type:MIME-Version; b=HB4MurpIBG5f5sTXICw8crW5Eyh7jsuH7RiwQWp37aeCVz7Enl4+ZFciq5AAn56EndF94OGO/wSRNzmJuAfpbzwAKrWROOzzCP4mBtefODmJw67wQeV2gOZP7CclcsgD9b/BXNedH/Gc8O6WYq+ETxPSg4XCvzeYoIBEvj0R35U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=kaspersky.com; spf=pass smtp.mailfrom=kaspersky.com; dkim=pass (2048-bit key) header.d=kaspersky.com header.i=@kaspersky.com header.b=gw2DlDjx; arc=none smtp.client-ip=91.103.66.155 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=kaspersky.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kaspersky.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kaspersky.com header.i=@kaspersky.com header.b="gw2DlDjx" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kaspersky.com; s=mail202505; t=1763730454; bh=VZSbMUCFGQuW/l8NxXF+VNPEjirlq3pKnNbZ2j41dCE=; h=From:To:Subject:Date:Message-ID:Content-Type:MIME-Version; b=gw2DlDjxaLXjp7FXldBaOC1zZZMA3A+HJi4TjrpPwMZTsffVk+MUKNb/DEhNV6Rhv axxxrv4PsLs7yEzvzig0FmtW/YUL/tiXUS6aNzAMWOZ8LQ+TxO8umk9motovCCYjvH TZLlP4TjJsCcLnX9qijZ48LALX7WyFWxipXlN1lMiXqlu/T1Rbi32MDSO7FFQcTHwV +h9xnC2W39FE+JsnhEXnoEZN/MIPACDHtXgvEsoZurU/vgltuFNV/7NOsRqCuGOhRd c2bSeha7B9wCopwJv7MyvHw1Z/d6ykoR27C3CL8NfOBVyAsV74amb321V+5dRsPwek qLYHxd1f5kntw== Received: from relay12.kaspersky-labs.com (localhost [127.0.0.1]) by relay12.kaspersky-labs.com (Postfix) with ESMTP id F1A235A18AA; Fri, 21 Nov 2025 16:07:33 +0300 (MSK) Received: from mail-hq2.kaspersky.com (unknown [91.103.66.200]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "mail-hq2.kaspersky.com", Issuer "Kaspersky MailRelays CA G3" (verified OK)) by mailhub12.kaspersky-labs.com (Postfix) with ESMTPS id 164515A17B1; Fri, 21 Nov 2025 16:07:32 +0300 (MSK) Received: from HQMAILSRV3.avp.ru (10.64.57.53) by HQMAILSRV2.avp.ru (10.64.57.52) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.29; Fri, 21 Nov 2025 16:07:32 +0300 Received: from HQMAILSRV3.avp.ru ([fe80::3db3:73bc:819f:30e7]) by HQMAILSRV3.avp.ru ([fe80::3db3:73bc:819f:30e7%10]) with mapi id 15.02.2562.029; Fri, 21 Nov 2025 16:07:32 +0300 From: Sergey Nalivayko To: Wolfram Sang , Alan Stern CC: "linux-media@vger.kernel.org" , "Mauro Carvalho Chehab" , Antoine Jacquet , Christophe JAILLET , "lvc-project@linuxtesting.org" , "syzbot+0335df380edd9bd3ff70@syzkaller.appspotmail.com" , "stable@vger.kernel.org" Subject: RE: [PATCH] dvb-usb: dtv5100: rewrite i2c message usb_control send/recv Thread-Topic: [PATCH] dvb-usb: dtv5100: rewrite i2c message usb_control send/recv Thread-Index: AQHcV9qGMUMw9E7/x02wMd1BZ/CtXLT59qeAgAA/8wCAAuY4sA== Date: Fri, 21 Nov 2025 13:07:32 +0000 Message-ID: References: <20251117155356.1912431-1-Sergey.Nalivayko@kaspersky.com> In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-kse-serverinfo: HQMAILSRV2.avp.ru, 9 x-kse-attachmentfiltering-interceptor-info: no applicable attachment filtering rules found x-kse-antivirus-interceptor-info: scan successful x-kse-antivirus-info: Clean, bases: 11/21/2025 11:55:00 AM x-kse-bulkmessagesfiltering-scan-result: InTheLimit Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-KSMG-AntiPhishing: NotDetected X-KSMG-AntiSpam-Interceptor-Info: not scanned X-KSMG-AntiSpam-Status: not scanned, disabled by settings X-KSMG-AntiVirus: Kaspersky Secure Mail Gateway, version 2.1.1.8310, bases: 2025/11/21 08:31:00 #27956385 X-KSMG-AntiVirus-Status: NotDetected, skipped X-KSMG-LinksScanning: NotDetected X-KSMG-Message-Action: skipped X-KSMG-Rule-ID: 52 >On Wed, Nov 19, 2025 at 18:51, Alan Stern wrote: >> Can't this problem be fixed more simply by setting the=20 >> I2C_AQ_NO_ZERO_LEN_READ adapter quirk flag, as in some of Wolfram=20 >> Sang's recent commits? On Wed, Nov 19, 2025 at 22:40, Wolfram Sang wrote: > I think so. Hmm, I searched the tree for potential candidates. Seems this= slipped through :( For reference, I fixed it in another media driver with = commit b5ae5a79825b ("media: usb: hdpvr: disable zero-length read messages"= ). Thanks for your comment. Unfortunately, setting the I2C_AQ_NO_ZERO_LEN_READ= adapter quirk does not solve the issue, as the problem occurs within the d= tv5100_i2c_msg() function itself when it receives a message of NON-ZERO len= gth. A message with length 1 arrives, but it's expected only in the case o= f a combined write/read operation, when two messages arrive simultaneously= via the I2C interface (this is explicitly checked in the condition). If th= ere's only one message, the last parameter of the dtv5100_i2c_msg() functi= on, rlen, is 0, and a parameter inconsistency error occurs.