From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C0AFB2475F7; Thu, 16 Jul 2026 13:39:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784209169; cv=none; b=Gcp+FIhYnwxYOo8ygOwBASU3dduai77f4LCmIbEzUdqSNpuZBLFIsLQ6R1R3kcJ2YWAutFQf7lf47RCzOEdLxYo7A60xcAuz0iy7K0ZMfeekI1PvGBVrhA4FRWQ0WheqIx3lLUknA5PyccGuWYHT5UreLAz7yZyNFVPt2Bt6S4o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784209169; c=relaxed/simple; bh=Vabj7MbKVu64k4m/sg6+nY1wXvPOPp14vcRI5JEnXYw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=dNJ3zMDngcfDtSDIZkD/551bcVkQ4Gn0VtWI8JzZP/shxY89GkDROlqRvLzjGKdpiY2Sv9VPaD7/kKSrI4j9wj06bWrVCsUaOOxGkH8hmXByAvGxi+E1Cx8bP31sAXRjuZO2cIW5KzvzxVz6oQG7tK+EDqe6vVGJ4z5Jw8Ra7q0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=pWN4GnyH; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="pWN4GnyH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 31CF01F00A3D; Thu, 16 Jul 2026 13:39:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784209168; bh=4IoluAj29j+mgfMZWJrsnM7OFh63WEKnAwAFALfTq1A=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=pWN4GnyHUYf6qzl8SRsVjgkESEVtQlYzZ5JEbJ/NSHOknzc37EIbbajKxGqdRVLVX XkAvwcau2qBwpEixM+8tDy6WGaF0phmv2rCwFW48Xl5e56IkofT3aZvvQO9BD/cMKP IStZW5RUQcq0VgczxZ4dDWtW6PkfbJ4g6NAbkSnU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Maoyi Xie , Takashi Iwai Subject: [PATCH 7.1 084/518] ALSA: caiaq: fix out-of-bounds read in the Traktor Kontrol S4 input parser Date: Thu, 16 Jul 2026 15:25:52 +0200 Message-ID: <20260716133049.700734841@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260716133047.772246337@linuxfoundation.org> References: <20260716133047.772246337@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Maoyi Xie commit f7f3f9fd81e7adbaa12c2e62ee07f0e094a543fd upstream. snd_usb_caiaq_tks4_dispatch() decodes the Traktor Kontrol S4 input stream in fixed 16-byte (TKS4_MSGBLOCK_SIZE) message blocks. On every iteration it advances buf and subtracts the block size while looping on "while (len)". len is urb->actual_length. That value is supplied by the device and is not guaranteed to be a multiple of 16. When a final short block leaves len between 1 and 15, the loop runs once more, reads up to buf[15], and then does "len -= TKS4_MSGBLOCK_SIZE". As len is unsigned this underflows to a huge value. The loop then keeps iterating and walking buf far past the end of the 512-byte ep4_in_buf, reading out of bounds until a bogus block id happens to be hit. Iterate only while a full message block is available. This stops the unsigned underflow and silently drops any trailing partial block, which carries no complete control value anyway. The sibling endpoint-4 parsers are not affected. The Traktor Kontrol X1 and Maschine arms in snd_usb_caiaq_ep4_reply_dispatch() floor urb->actual_length before dispatching. Fixes: 15c5ab607045 ("ALSA: snd-usb-caiaq: Add support for Traktor Kontrol S4") Cc: stable@vger.kernel.org Signed-off-by: Maoyi Xie Link: https://patch.msgid.link/178176259547.3343534.2724779296835237429@maoyixie.com Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- sound/usb/caiaq/input.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/sound/usb/caiaq/input.c +++ b/sound/usb/caiaq/input.c @@ -330,7 +330,7 @@ static void snd_usb_caiaq_tks4_dispatch( { struct device *dev = caiaqdev_to_dev(cdev); - while (len) { + while (len >= TKS4_MSGBLOCK_SIZE) { unsigned int i, block_id = (buf[0] << 8) | buf[1]; switch (block_id) {