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=1794204513; b=JfLKzUgKizWPm/E8lq5i4cqiQH6OSuvdg7jmdt0NPWVjQ8aiSZqM/jF49bYlqmHYQVbH /N1Jyj7K3jTmiPx+F/9XefjbTKRZLGjEJqj4PtZDkfBXTjig2OVT6utjwdycQK5KUNzf1 VuKwWnv0w1XhQLNNH6oBmcuGEB0tC86JbCMEGUeSrnYfQ+JdGqCHHCDLf/HeBGMVVLvJF JhCHb00Q/CVg1qixvwbgkGasSZYc9tHuMMC6vrv+QWbotTb+YdtarWzFb6A/z7Alkvgr8 J8k7puA2nb/qICDNnJs04tt+l9dNU5j8tzPCr2r1QfOOR7dC7PQbdhLn7yj+RYBT+Ng== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794204513; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=iI3BG1Rbc3VZQ5N/Rpxl105c4moIK+Xy8hOxv/WPZ64=; b=gG0qZgrKZXEyvYSCyLyIfl0An0qMwEqY0BqjS6B0F2g7d28xeOkf/z3HHMVYLQznln1J SSlKuTowdWh3S/to+NdFLAS6RxZskth10vwt54VUzZIrMYvR91K6e/ALHEfW27AXX7Ixq E/rb3unYpUT3rfik+zxsZvCR5DQC9xKMtEbzib+dh2s3t149hBd+oUJLkHV4wzAbvhwHG bpNySEKyE+sFMD/4Yx71dxcrBR2gBX14bONftHCksPsecp2mTi2tYvsNx817tyIKhL0i9 ahFpF9/Q2Ynct++KL8rO0BNz+4OOcx5QY4GqXLUAY5y7yugZpzh4FU53/TQkaHpFP1w== 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=PArVZCTg; 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 8B40C606A321 for ; Mon, 9 Nov 2026 06:08:33 +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=PArVZCTg Received: by smtp.kernel.org (Postfix) with ESMTPSA id 089E41F0089F; Mon, 9 Nov 2026 06:08:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794204513; bh=iI3BG1Rbc3VZQ5N/Rpxl105c4moIK+Xy8hOxv/WPZ64=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=PArVZCTguL5bDo2SN9O8ElG+8UZZVFS5LvIw3GXrc7hPtMCZpNh7wf2Eu33CC2u6D 7gzvGcH//6Ef4PgDTe9Lp4WUAKc5KYBTnSSaoSKunZsV69xDuTAyO6OY3Ovf05Hqhg T/SDKi0D7HKbtaC9pFKLxOjM533Ip3cvmy2zTX3gfj4tBKXj9tLTqtxABN8eYKaM5X sHcqUmzIa2ZhjyvlQQmMSq6/c+cq5Tdm6dwKBSJWQfLsVWMcdSrfL70QEWxU/fO+Zv E0qOiwW3qWDtj7ZUJiEVtWxM5SS3eQLzVusMRXIBpddDd/xHvH6WGiIhal7adIMI3C h7XqRtmcKHgAg== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v5 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-v5-2-f16d0b648bc2@gmail.com> References: <20261109-b4-gadgetfs-ep0-v5-0-f16d0b648bc2@gmail.com> <20261109-b4-gadgetfs-ep0-v5-2-f16d0b648bc2@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Mon, 09 Nov 2026 06:08:32 +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-v5-0-f16d0b648bc2@gmail.com?part=3D2