From nobody Sun Feb 8 22:35:16 2026 Received: from netrider.rowland.org (netrider.rowland.org [192.131.102.5]) by smtp.subspace.kernel.org (Postfix) with SMTP id 870DF12FB0B for ; Thu, 29 Feb 2024 19:30:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.131.102.5 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709235011; cv=none; b=gSDy5yJncT+Lr65xmvuSA5KWJ92Iu5xYhb6/mCqoruWKLafjkpn4XYSP3PHLkuo5vr+aFJ8tFS3SJzV3cXfkQqM2XZwjEey1VYJ5FrddLGFUomjniVjOXxK6IPWcNwJA7dmcF6zJyFZNIX4B/XKB85jQoZmgwF1FD5dcTN6bWgQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709235011; c=relaxed/simple; bh=zIkZcYh+X6JTE1BjxXkppg86AYseCYK4cRr264Zk2Jg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=u37eD8AW1SnsDJnsWElDt6ORHxuWZZCKy5Rf7mlhIa9Wtr9SdNrG0DLLuYh4YjVKLeqdeMg+v8ucb9+DU37mTDFfWiPLyCgzfpi25KFyQgtmbUalg/ZjjhnP9YJ/qsYdgT3RcD3KBPMEwWMXvgl+RcwzMl7OCR97Udtlbt/CRBQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=rowland.harvard.edu; spf=pass smtp.mailfrom=netrider.rowland.org; arc=none smtp.client-ip=192.131.102.5 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=rowland.harvard.edu Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=netrider.rowland.org Received: (qmail 12670 invoked by uid 1000); 29 Feb 2024 14:30:06 -0500 Date: Thu, 29 Feb 2024 14:30:06 -0500 From: Alan Stern To: Greg KH Cc: syzbot , bvanassche@acm.org, emilne@redhat.com, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, martin.petersen@oracle.com, nogikh@google.com, syzkaller-bugs@googlegroups.com, tasos@tasossah.com, usb-storage@lists.one-eyed-alien.net Subject: [PATCH] USB: usb-storage: Prevent divide-by-0 error in isd200_ata_command Message-ID: References: <380909e4-6e0a-402f-b3ac-de07e520c910@rowland.harvard.edu> <000000000000102fe606127a67f6@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <000000000000102fe606127a67f6@google.com> Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The isd200 sub-driver in usb-storage uses the HEADS and SECTORS values in the ATA ID information to calculate cylinder and head values when creating a CDB for READ or WRITE commands. The calculation involves division and modulus operations, which will cause a crash if either of these values is 0. While this never happens with a genuine device, it could happen with a flawed or subversive emulation, as reported by the=20 syzbot fuzzer. Protect against this possibility by refusing to bind to the device if either the ATA_ID_HEADS or ATA_ID_SECTORS value in the device's ID information is 0. This requires isd200_Initialization() to return a negative error code when initialization fails; currently it always returns 0 (even when there is an error). Signed-off-by: Alan Stern Reported-and-tested-by: syzbot+28748250ab47a8f04100@syzkaller.appspotmail.c= om Link: https://lore.kernel.org/linux-usb/0000000000003eb868061245ba7f@google= .com/ Fixes: 1da177e4c3f4 ("v2.6.12-rc2") Cc: Reviewed-by: Martin K. Petersen Reviewed-by: PrasannaKumar Muralidharan --- drivers/usb/storage/isd200.c | 23 ++++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-) Index: usb-devel/drivers/usb/storage/isd200.c =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D --- usb-devel.orig/drivers/usb/storage/isd200.c +++ usb-devel/drivers/usb/storage/isd200.c @@ -1105,7 +1105,7 @@ static void isd200_dump_driveid(struct u static int isd200_get_inquiry_data( struct us_data *us ) { struct isd200_info *info =3D (struct isd200_info *)us->extra; - int retStatus =3D ISD200_GOOD; + int retStatus; u16 *id =3D info->id; =20 usb_stor_dbg(us, "Entering isd200_get_inquiry_data\n"); @@ -1137,6 +1137,13 @@ static int isd200_get_inquiry_data( stru isd200_fix_driveid(id); isd200_dump_driveid(us, id); =20 + /* Prevent division by 0 in isd200_scsi_to_ata() */ + if (id[ATA_ID_HEADS] =3D=3D 0 || id[ATA_ID_SECTORS] =3D=3D 0) { + usb_stor_dbg(us, " Invalid ATA Identify data\n"); + retStatus =3D ISD200_ERROR; + goto Done; + } + memset(&info->InquiryData, 0, sizeof(info->InquiryData)); =20 /* Standard IDE interface only supports disks */ @@ -1202,6 +1209,7 @@ static int isd200_get_inquiry_data( stru } } =20 + Done: usb_stor_dbg(us, "Leaving isd200_get_inquiry_data %08X\n", retStatus); =20 return(retStatus); @@ -1481,22 +1489,27 @@ static int isd200_init_info(struct us_da =20 static int isd200_Initialization(struct us_data *us) { + int rc =3D 0; + usb_stor_dbg(us, "ISD200 Initialization...\n"); =20 /* Initialize ISD200 info struct */ =20 - if (isd200_init_info(us) =3D=3D ISD200_ERROR) { + if (isd200_init_info(us) < 0) { usb_stor_dbg(us, "ERROR Initializing ISD200 Info struct\n"); + rc =3D -ENOMEM; } else { /* Get device specific data */ =20 - if (isd200_get_inquiry_data(us) !=3D ISD200_GOOD) + if (isd200_get_inquiry_data(us) !=3D ISD200_GOOD) { usb_stor_dbg(us, "ISD200 Initialization Failure\n"); - else + rc =3D -EINVAL; + } else { usb_stor_dbg(us, "ISD200 Initialization complete\n"); + } } =20 - return 0; + return rc; }