From nobody Fri Dec 19 11:50:01 2025 Received: from mail-oo1-f69.google.com (mail-oo1-f69.google.com [209.85.161.69]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AF52E223DEA for ; Mon, 8 Dec 2025 02:33:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.69 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765161183; cv=none; b=qZIJQNwiRRTZxWgMy0urh3mdYa7QJKLG0Gma5kNIh+L7muB+l2eE9De7gn/M7dfffaxOBYNhs1gncweaFFZ9VCMOxU+YE4Y1OvIUhN0rTAXXr6yExHK7gWjI3QA6T6TPGYzDOYIufYTLhMLZCCagfgLo9yDE2dRx3ExwdnMn6/c= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765161183; c=relaxed/simple; bh=8fdwUF1jqQ6qYvBjLkpJI6xpIAV8ob6WNCPOeM5zJgA=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=NonoBWqfgmOSpcd2A69flloauOXx37Ychr53o7N1X4zLKNUmNj3xx0/NV21CPaUAMWiOeoQmSHCjO8E99K7SWFqDr6GaLT5qQQlW0k4PZ+FQcx+ePa2/80EJoZhiitCeE72fnRc3zij3A/9tBjWroRGvFA7OKI6PsFakXvxBpXw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.161.69 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-oo1-f69.google.com with SMTP id 006d021491bc7-656bc3a7ab3so6237565eaf.2 for ; Sun, 07 Dec 2025 18:33:01 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1765161181; x=1765765981; h=content-transfer-encoding:to:from:subject:message-id:in-reply-to :date:mime-version:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=pm2hSmDX5Dqr/3x55ZQebE+vwr+P0OJOQrNjd7CvMl0=; b=LNGxJHdMmtjKmN3YA2y/VbXinWbIGo2chRXHBgCrKEZTXHqioI7kdJvmFQy5wJrz61 c3JqyVbC8qBp1aZqGe2lDqB/r2PVerzE7KQH5gq2F8FiLrBSvdQBTTWTi7eC6Q7EbbD1 4CL6pGi6oZMMZH/14Cm83o2l9FjwVtdOSn7numS6NX9rkvv2plmE7Odn7Jqu1ppobdvT nBJu3zUHdMiX7y0wkteR6TQ7xH66DqFhJE9+aUmfiJDwfEQ+qfZ53si1/zQBqQia85UH Rcg8Op75GB/0uWcC9eE1qMUfyncxq9TdGLvOK+bWo3z0zgWwfJ/4bceUYWBWLbe13bEv NvtQ== X-Gm-Message-State: AOJu0Yzwc9MBXj6mFHaS3UL11MfM/D/6TUITRgu3KHXa+WeQEtobkGLa b+SitEXcn6KcAF41YC+9tMsC+BmDPmd2EDlYWCq/RuZaf3uCR0RG64ALa8q0nudJjWMx0xh6qDx UNAQlp13EV0FBqgRvSdX2p3qvOTw4Z4fTUCZEvCQMC3ZBtIEEH2ECRJkhxb0= X-Google-Smtp-Source: AGHT+IGf/flsCPaFxacS2njSA9zsJB94AaNLlZhiws9QFqU5f7HDsf5IPPJTY+Ek5kr0pXGoXRD5jNaaVL6oE1oENyB/YuuLQBe6 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:8183:b0:659:9a49:8f91 with SMTP id 006d021491bc7-6599a8b3e7dmr2668061eaf.10.1765161180837; Sun, 07 Dec 2025 18:33:00 -0800 (PST) Date: Sun, 07 Dec 2025 18:33:00 -0800 In-Reply-To: <68a7b69f.050a0220.37038e.0047.GAE@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <693638dc.a70a0220.38f243.0076.GAE@google.com> Subject: Forwarded: [PATCH] media: dw2102: validate I2C messages in su3000_i2c_transfer() From: syzbot To: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" For archival purposes, forwarding an incoming command email to linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com. *** Subject: [PATCH] media: dw2102: validate I2C messages in su3000_i2c_transfe= r() Author: dharanitharan725@gmail.com syzbot reports a general protection fault caused by su3000_i2c_transfer() dereferencing msg->buf without validating the message length or buffer pointer. Although i2c-dev blocks zero-length messages, malformed I=C2=B2C messages can still reach the driver through the DVB USB subsystem. #syz test Add strict validation of each message to prevent NULL-pointer dereferences. Reported-by: syzbot+d99f3a288cc7d8ef60fb@syzkaller.appspotmail.com Fixes: 0e148a522b84 ("media: dw2102: Don't translate i2c read into write") Signed-off-by: Dharanitharan R --- drivers/media/usb/dvb-usb/dw2102.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/drivers/media/usb/dvb-usb/dw2102.c b/drivers/media/usb/dvb-usb= /dw2102.c index 4fecf2f965e9..0dd210ea16f3 100644 --- a/drivers/media/usb/dvb-usb/dw2102.c +++ b/drivers/media/usb/dvb-usb/dw2102.c @@ -733,6 +733,36 @@ static int su3000_i2c_transfer(struct i2c_adapter *ada= p, struct i2c_msg msg[], return -EAGAIN; } =20 + /* Validate incoming I=C2=B2C messages */ + if (!msg || num <=3D 0) { + mutex_unlock(&d->data_mutex); + mutex_unlock(&d->i2c_mutex); + return -EINVAL; + } + + for (j =3D 0; j < num; j++) { + /* msg buffer must exist */ + if (!msg[j].buf) { + mutex_unlock(&d->data_mutex); + mutex_unlock(&d->i2c_mutex); + return -EINVAL; + } + + /* zero or negative length is invalid */ + if (msg[j].len <=3D 0) { + mutex_unlock(&d->data_mutex); + mutex_unlock(&d->i2c_mutex); + return -EINVAL; + } + + /* protect against unreasonable sizes */ + if (msg[j].len > 256) { + mutex_unlock(&d->data_mutex); + mutex_unlock(&d->i2c_mutex); + return -EOPNOTSUPP; + } + } + j =3D 0; while (j < num) { switch (msg[j].addr) { --=20 2.43.0