From nobody Sat Jul 25 22:32:26 2026 Received: from mail-pl1-f175.google.com (mail-pl1-f175.google.com [209.85.214.175]) (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 893DF201113 for ; Mon, 13 Jul 2026 05:38:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.175 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783921108; cv=none; b=G/AYPmCUr1VYp8yBt909z7r7zEGHvdJRdFZp9AzsGKCeqd0ySNDRx79F189Mk853fIHT4Trw1fuRw0508EfBM2j1IX0UnCLmCIatFaJ3IJ4kmQNoeXbXiM3uwvFo0aaDRAP/asrhOZdO1PAE5dkrG34dZJd18019Xamac42DN5Q= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783921108; c=relaxed/simple; bh=eauprXwXHzSDmMa8lR/3cLb7PNmC7AfAZ0kFs8RPt+E=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=OQM1V/8vdAhGFTiljBzbeyqLSOUI2JsOiy1Q4kefXqZQlDCG3nczEJfPrabJCIK8H70RGFbG6nY2Myvx843KDCxoxtGRMqGKPEVxe70TprT4shIZOA4PAQNjw8shpFQ3hBk+/wzl0hY6S54ExiFQqAz/9KfHFZG/nSV3QZNkknA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=cJbCh6ED; arc=none smtp.client-ip=209.85.214.175 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="cJbCh6ED" Received: by mail-pl1-f175.google.com with SMTP id d9443c01a7336-2ca64c3ce5fso31044995ad.3 for ; Sun, 12 Jul 2026 22:38:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1783921107; x=1784525907; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=ivIVSVi0tei/ccOpIZ9e7O0axGdkjSgdrLeU2t78Aik=; b=cJbCh6EDCQog2mHYuj+NYerBKQFOpfkJs7rLExyfifiER2REhdqaDSJojN5FaLbqrF NhM0oCxw3DGQHMYshUsr6swHS4nzkWJwOjuEBC5O14UWsR56HetcNxd1HVTypIP2fk3n 3gljmi5Hw5FRKNutKinPDhz8+SOn1JbYAM8NTvfYl/ZUfYwTWi9oGrE0l9aN96YagqJd JPgcEqkzTJDtD9GG5NOwdZ2R6RTiIfKdHdZC1CTPVncZo8PEsVAS0Yd6kn2IkGSqWfDa //HBmKbBOFMlATU6VN+wpkXPqbx7kUGY351Qh6qYAiUaVO7tN++RT19XZbKcI5VzTKZk HY+g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1783921107; x=1784525907; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=ivIVSVi0tei/ccOpIZ9e7O0axGdkjSgdrLeU2t78Aik=; b=YImVhZRhfQfsakeg5J4Y86Zs2jJi/2nPnTXzha5wOZ1zXvGkPpywHVtTbrXqkbEOOA IFHcaoZH94e1Ik1XXD4IIbojZS7mVkIxFsqBl4QoCx52T4KDkOh59E/ijnTTO7c+mnd8 XJ5PEMD+f4nyWTpP3MNa+E3rDoHrq3gnVu2LDGUTJdZlUnrriqkSn2lNLVTz9hBmKdv1 eF9IhKAJsSnE06smEMam7c613Rx+xntdWibbGU8YyOs0N3+SMQlw8j4x6hrJQDThV5gO N530BBcandfy32/MGjBFjWK+ZcH148mXBeFbz0wqlmNdZDPDVsAThEA5DaKVxSJHgmOb Boug== X-Forwarded-Encrypted: i=1; AHgh+RoK0x+/FGjC1KRpIr80vO9ERM1n0FTDee9GYI8iKJlZqWxR7wZV/bSVj15oC5LS5bEu1oUyh/WzdRq+isY=@vger.kernel.org X-Gm-Message-State: AOJu0YysYkEnCy7hVfv9/w2C1Quju9YUU6wdVYa1zN9aDvZ7s+Q/WIMh ybgcAFvpENj3WTACLQx3rHxF+Fd5KmBIr+yoqKfVpgKayxYs/pWwEYDT X-Gm-Gg: AfdE7cno8QDkUfOspK3Y5h+i/Fq6vvlOgDVqma7b0gsiwtUGMzhJVe1VavjQ177dpFL sZaMDaMZXzP3WJV88J3g6i2uyjv1CmgMm24RxawxtVHtytFifgnIBlyOrxU0s9CIZc6u680EEzo pdYVBkzobjWK3AyS03YdxfmD3sH9tGJlFx5ZrI9g0yjKSM+rjR+xgDPxhkven75KddW75hwLRtq 9sS+q63DiIyqI0hsknyebQF/LbSwYIEpiqA6pn+nXorWHjTSDzR845i4PL3LU8zHo9dLLdTXes6 ItMnr+jA++CS/zIenn+QrC5oBabvlMAY94xyYgHm+2kmNS8xY/PUC0qhhrP02v2ewl4sad6IVhw fKasJ7ahwOFDc0nuVhiANLmu+wpY+T2/sYRvz0nD/yNVht+WWRxTvubP7PBnyi8FPuk7dyghRcI YFFzU3zpRVsATJwbCpMiuK5t8K7ymE2QtwIHt4/I4wO2ATYgSKLSbOXZq8b7kDsW/5fwVGOqSiM psPAVnI74OrK0bh4+8DRvZu5HQvT57wjW5/Cdbpl4vP5krGVD+MjuDCgB4x5jGqKzwvNyTMdgAo O816VbdB1YNEIHipfr6yEoMAzae1k9j10m9lLeYhB7SatyL7vON138FCZspOZvKkf4Qi4qLcWRG Ls3IhefojeyxlAtTqLsYNnIZpiMurgkSfbQw= X-Received: by 2002:a05:6a21:6f13:b0:3b4:b340:411d with SMTP id adf61e73a8af0-3c1108b5fe1mr8860026637.24.1783921106934; Sun, 12 Jul 2026 22:38:26 -0700 (PDT) Received: from HEXER.localdomain ([175.157.29.69]) by smtp.gmail.com with ESMTPSA id 5a478bee46e88-313b4b97661sm32915270eec.7.2026.07.12.22.38.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 12 Jul 2026 22:38:26 -0700 (PDT) From: Kanishka De Silva To: gregkh@linuxfoundation.org Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Kanishka De Silva , stable@vger.kernel.org Subject: [PATCH] usb: adutux: fix unlocked read_buffer_length write in adu_open() Date: Mon, 13 Jul 2026 11:07:37 +0530 Message-ID: <20260713053737.912-1-kpskanna1915@gmail.com> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026071358-illusion-basics-1146@gregkh> References: <2026071358-illusion-basics-1146@gregkh> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" adu_open() clears dev->read_buffer_length while holding only adutux_mutex, but every other path that touches this field (adu_interrupt_in_callback() and adu_read()) correctly holds dev->buflock, per the locking scheme documented at the top of this file. This is a data race: an IRQ callback incrementing read_buffer_length concurrently with adu_open() clearing it can have its update silently lost, corrupting buffer state. Take buflock around the reset to bring adu_open() in line with the documented locking contract. Cc: stable@vger.kernel.org Signed-off-by: Kanishka De Silva --- drivers/usb/misc/adutux.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/usb/misc/adutux.c b/drivers/usb/misc/adutux.c index 369d0d2..606ef91 100644 --- a/drivers/usb/misc/adutux.c +++ b/drivers/usb/misc/adutux.c @@ -228,6 +228,7 @@ static int adu_open(struct inode *inode, struct file *f= ile) { struct adu_device *dev =3D NULL; struct usb_interface *interface; + unsigned long flags; int subminor; int retval; =20 @@ -265,7 +266,9 @@ static int adu_open(struct inode *inode, struct file *f= ile) file->private_data =3D dev; =20 /* initialize in direction */ + spin_lock_irqsave(&dev->buflock, flags); dev->read_buffer_length =3D 0; + spin_unlock_irqrestore(&dev->buflock, flags); =20 /* fixup first read by having urb waiting for it */ usb_fill_int_urb(dev->interrupt_in_urb, dev->udev, --=20 2.43.0