From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794208371; b=Xhrlo+vVqAlYklDznqAExuyHQhEgG7Z6vVdSrSXIBUY82bkstVo2yh78cq9frG3Ajodo WpXB1Ie70pyEE1+PgfNA03JJaPjrt9jGIlfK0KlbxOdEsT2Y6tst4FZREHbbIl7yGf0Hh nXURSPoRzThGgAGyapPWdvyYpTdn535JGml9W/MOuHteTvzqP4sY6VY5Xm+5n2kQl8nN3 PFcNi+1vdq/NZoX+yI+VNjLPdAuOZv7IBc4J+hofqruKFy1UOAJppYyG0E6MU/b4lAlze y+5uT+FrrbspkdFJCbfaYmEspIUhAn0wG0q+v1jJFOV1B3z4/wwLKX75W98RGTXbxrg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794208371; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=1riSLZfoWaz271t/fvKN3KfaEHPOR5iDelP5GjNFgbc=; b=UTpwaInUtaQssqptgdzKnx9DNGc3NNMPM/TdeX2oyXm4LlR5puBb+lqpzHjWjlOwCznj Gf2vG4osIt0zoDEu4OqU55Nwxc5VYgZjJ4iAPvzcmEtRTZp/eXW1FpejOf1gSyxoDFJrK seWN84MEd5uzGUoYVbqer/bDutGfYw2GLL0pOWgHMLg8N4MK3Cv50IzvLsXfyLXp0nv0U dBWFE5GaeQcKE6tarb7eYfYvb28Z2K/rUz76F1ZSK2bHn5sG+FjaIgz4A7MltjTU2ZMPR kwTJSyP0K4tiydbNsJHUnBq5ktUTBz4OhU/1sIW0Q1aoAchDDerBL4NPmv33D+fy0Bw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=UGaVTrvE; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 96DDB606A322 for ; Mon, 9 Nov 2026 07:12:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=UGaVTrvE Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4D2851F0089F; Mon, 9 Nov 2026 07:12:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794208371; bh=1riSLZfoWaz271t/fvKN3KfaEHPOR5iDelP5GjNFgbc=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=UGaVTrvEOxlbhnv1fv24uVnzRUkZ74TM8EybSCBIFTbmFhGXRt/ocIYw0jfinlg1U VzvqWL33DLBMTNc/QHcWByftVNQh5WMTxQV9TMCP7+s/+PUnj3OrVQbwWCPTMfRoru teJKI/JaMwFVi5X4JUE9JHzlxTKDRtqMK1cIND0XrMiFgx/yeFkbiCphvIgCkVCaKP ulCZAsAKya/WZ+BdnaVv3I89vksTIxQkqTnEOVfvzATwjZ3EBFAMAUXwGUFmLBzBN5 ACcOnQB/XUO1gy4WAk9/w/hCFUnUs+37QyX6HBmImINKQuvUa6zOsu/V0cTtXKu+tQ dXd1AjUD6iivg== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v6 2/3] usb: gadget: gadgetfs: prevent ep0 event counter underflow Reply-To: sashiko-reviews@lists.linux.dev To: "Jing Lin" Cc: linux-usb@vger.kernel.org In-Reply-To: <20261109-b4-gadgetfs-ep0-v6-2-b410e3dced89@gmail.com> References: <20261109-b4-gadgetfs-ep0-v6-0-b410e3dced89@gmail.com> <20261109-b4-gadgetfs-ep0-v6-2-b410e3dced89@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Mon, 09 Nov 2026 07:12:50 +0000 X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list > From: Jing Lin >=20 > ep0_read() snapshots dev->ev_next, drops dev->lock while copy_to_user() > runs directly from dev->event[], and subtracts the snapshot afterwards. > A concurrent disconnect, connect, setup, or another reader can reset, > deduplicate, or consume the queue in that window. This races on > dev->event[], can drop newly arrived GADGETFS_SETUP events, and wraps > dev->ev_next if the queue shrinks below the snapshot. >=20 > Dequeue the events into the local buffer and update dev->ev_next before > dropping dev->lock for copy_to_user(). >=20 > Fixes: 1da177e4c3f41 ("Linux-2.6.12-rc2") > Cc: stable@vger.kernel.org > Signed-off-by: Jing Lin Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261109-b4-gadgetf= s-ep0-v6-0-b410e3dced89@gmail.com?part=3D2