From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.zeus03.de (zeus03.de [194.117.254.33]) (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 4F8AB1E1E18 for ; Wed, 26 Mar 2025 15:54:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=194.117.254.33 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743004463; cv=none; b=pHIZaQu+EfTsrMpJ9VpFxB565PSH+Od2LS7vMwV76SL/2XwuTpIUdSWvxVVkkWugVEBXdiJI0K1ibZckUc4Kw4W26a0kLcVPwZolPtzosXIJ0PWy/wkfLmq/uHsMugqqfFndeqFdu29YE4nW3o7ibsSlHcgQqdPhZ13bAomb8VE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743004463; c=relaxed/simple; bh=FDUGpv8wkh/L+zMY5NUyNY08daDDaIIU0e+pvQ9oYY8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=REHay4mc6qp98Ysj9biOnLOkm7ZRiKs3mnJp5E8ykph2q8QSo+CqAUB/dCeHAzzWnXP37OTmWA3B9Krjp6wcL+XZb2PBSoCahsL3nQcKe9dsyn196VQGQOj6fQB3QZQGYUmXHM4QjJByvqPI1Mfq5lCwIndITXUAry4SLDAfaL8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sang-engineering.com; spf=pass smtp.mailfrom=sang-engineering.com; dkim=pass (2048-bit key) header.d=sang-engineering.com header.i=@sang-engineering.com header.b=h2mDSSnc; arc=none smtp.client-ip=194.117.254.33 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sang-engineering.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sang-engineering.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=sang-engineering.com header.i=@sang-engineering.com header.b="h2mDSSnc" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= sang-engineering.com; h=date:from:to:cc:subject:message-id :references:mime-version:content-type:in-reply-to; s=k1; bh=zSLh 6u4uG99qS3Ry66qHxhfF2ZHYx/p/tn5fAPvS/l8=; b=h2mDSSnclj1MbnFQxta1 sCPwt85MjWu75wLtwX+zd4fkTII+ZZilK4FjkrDY//3Rlr2g5qRFl0/MBMz/jMng v5MAmMYS9INt2nMfSVrqzpoKXBiRZ+cXrdZxCDvdK6hK2dXIbTIm2kVgHXkyOtk0 djQLFRZazRVKxP+BHqWUT0kqrE8DqdGJSubN1oNA1dtbNrAOkifdN+7+ghmb6sZq V2ST7/Axd5GaHmH+clfvXilpbiw5kGsh0KsA8nJvG5h4jp3PALiR4EiW/Y641ST/ YHe3AfyuGnqW46PM/XYdXxm1Gyx6HzqTG2n732dQLYl/R0ewiURj8ugbybhqtYbb og== Received: (qmail 3662529 invoked from network); 26 Mar 2025 16:54:10 +0100 Received: by mail.zeus03.de with UTF8SMTPSA (TLS_AES_256_GCM_SHA384 encrypted, authenticated); 26 Mar 2025 16:54:10 +0100 X-UD-Smtp-Session: l3s3148p1@rV0S2UAxBNIujnsv Date: Wed, 26 Mar 2025 16:54:09 +0100 From: Wolfram Sang To: Alan Stern Cc: syzbot , gregkh@linuxfoundation.org, linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, syzkaller-bugs@googlegroups.com Subject: Re: [PATCH v2] media: dvb: usb: Fix WARNING in dib0700_i2c_xfer/usb_submit_urb Message-ID: Mail-Followup-To: Wolfram Sang , Alan Stern , syzbot , gregkh@linuxfoundation.org, linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, syzkaller-bugs@googlegroups.com References: <6bb3b80b-a808-4992-8666-535ed9a5c980@rowland.harvard.edu> <67e2fed5.050a0220.a7ebc.0053.GAE@google.com> <29db5fdc-13c9-45f0-9183-c80d637725c6@rowland.harvard.edu> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="6+vuiCGawqSgBAHG" Content-Disposition: inline In-Reply-To: --6+vuiCGawqSgBAHG Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Mar 26, 2025 at 11:28:19AM -0400, Alan Stern wrote: > The syzbot fuzzer reported a WARNING related to the dib0700 dvb-usb > driver: >=20 > usb 1-1: BOGUS control dir, pipe 80000f80 doesn't match bRequestType c0 > WARNING: CPU: 1 PID: 5901 at drivers/usb/core/urb.c:413 usb_submit_urb+0x= 11d9/0x18c0 drivers/usb/core/urb.c:411 > ... > Call Trace: > > usb_start_wait_urb+0x113/0x520 drivers/usb/core/message.c:59 > usb_internal_control_msg drivers/usb/core/message.c:103 [inline] > usb_control_msg+0x2b1/0x4c0 drivers/usb/core/message.c:154 > dib0700_ctrl_rd drivers/media/usb/dvb-usb/dib0700_core.c:95 [inline] > dib0700_i2c_xfer_legacy drivers/media/usb/dvb-usb/dib0700_core.c:315 [in= line] > dib0700_i2c_xfer+0xc53/0x1060 drivers/media/usb/dvb-usb/dib0700_core.c:3= 61 > __i2c_transfer+0x866/0x2220 > i2c_transfer+0x271/0x3b0 drivers/i2c/i2c-core-base.c:2315 > i2cdev_ioctl_rdwr+0x452/0x710 drivers/i2c/i2c-dev.c:306 > i2cdev_ioctl+0x759/0x9f0 drivers/i2c/i2c-dev.c:467 > vfs_ioctl fs/ioctl.c:51 [inline] >=20 > Evidently the fuzzer submitted an I2C transfer containing a length-0 > read message. The dib0700 driver translated this more or less > literally into a length-0 USB read request. But the USB protocol does > not allow reads to have length 0; all length-0 transfers are > considered to be writes. Hence the WARNING above. >=20 > Fix the problem by adding the I2C_AQ_NO_ZERO_LEN_READ adapter quirk > flag to all the USB I2C adapter devices managed by dvb-usb-i2c.c, > following Wolfram Sang's suggestion. This tells the I2C core not to > allow length-0 read messages. >=20 > Reported-by: syzbot+c38e5e60d0041a99dbf5@syzkaller.appspotmail.com > Tested-by: syzbot+c38e5e60d0041a99dbf5@syzkaller.appspotmail.com > Suggested-by: Wolfram Sang > Signed-off-by: Alan Stern > Link: https://lore.kernel.org/linux-usb/67e1a1f5.050a0220.a7ebc.0029.GAE@= google.com/ Reviewed-by: Wolfram Sang Thanks for taking care of it! --6+vuiCGawqSgBAHG Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEOZGx6rniZ1Gk92RdFA3kzBSgKbYFAmfkIx4ACgkQFA3kzBSg KbZQlA/9F/3h5gABvKbiy6ojaD5HfokFTVzFJ/YjhFlvQTXoyoZRIH4BxNRWH2v7 nVafhaGZ9ynojOtXwxASFODJLRgaEQmB3+8Bot9brgaV0ei9TY8mVknRK3mCby/I a7YtMM5QsLtlrr3NB6jegE5qKhCKRtLOArYseRGh+fnpb2FkL8rnnZt/p9IsiiVe 8zVDnBBpc7BjrRuD7bg9zANX53YTlLjVQ2VhxzMyyvxIkUBneMWxxoqgFOSG9OEz VlrioknZ6zxjBHBzlzliQylbRUWPBq6Cn4Rt20ST/VaMWg8tPPP/CLKDIvGeq0be R3YU67eSLmuj56uk8OVmnJcf1To4LCyeT3yvvsrVhNu72olMYwxP+tRabhxVphwL 6eWL1jdJt1BbfSdNXCiKiP6l3hD0bKz04N3tj+bIyLHRiUxd474+H4Vgzzped/j1 4734hpxf5QWsz35CVGAMXGZl7sr39lhB3cU2RZQsigUferCMwz4pD78u19TbkFpz Vx/EPpxLSpCHBE/UimG2hEpr5/R8e23D44Bu6diZpeFoRVa75MO9fi78RAUqk5we cduCy7Ciuhagp+a0Im+OkxoVuk/7u/3/dMUgr9Kh2yRKKhuuD8Tljss32sHBJpDb QpLjPlpdqKoGSts9dr/K8HRm5PBX62WA668VkkUnZLjSutYjW0I= =Qco2 -----END PGP SIGNATURE----- --6+vuiCGawqSgBAHG--