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 F142F480DC6 for ; Thu, 4 Jun 2026 13:55:04 +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=1780581306; cv=none; b=axX99aI5O6qXor1f9biVZbEcQAxdZ323arPMHmj4/e7F6GBFmilEN7mE5rXFfcgXNR8AxPU2QdxWlNAJ3c70mZzkz07tSCoaQCRQ/+5v2mCTZ2uYT02+OCBWWESUvmOXFuYGe8o0VIQTpVl4Rp3+ai2Wmw6tVZg81NormumbVkU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780581306; c=relaxed/simple; bh=ahwY0mo7nj38JbvOSS27DVdv7w503GVt/q5wtKMtv9w=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=R6dP11DIvjOEveaBQpZDp8CfRhpo+6IjvKt/I5wqs/KbEXAru5I9eTz0sQEAADcGEF8IoOQTkYn0QkJbH4j+LK4YHjLwJ/PTu++dRrUHWiPxR0VZ7MJScIzbBO0Ke5ZcUzPNpUGLuT1nXXy5r0pPyUqu7ACfiiYHK433ms7Ny2U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=BB8nLwZG; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="BB8nLwZG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 288BA1F00893; Thu, 4 Jun 2026 13:55:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780581304; bh=mLEf8AF3GUQqFeTecbf8z690NrO+UZIWTLct2P4pf4U=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=BB8nLwZGsfW2lkf0+wrLsgnv2i/W0Ka3O+EOrARlL4FKgbnnflXsTxl8ns3taEOEn tuz1BArIJXLrCptlHo0Ki+Vji4FWgKdEf4K8/I6NAHet8F3F4uwj1VHmiUZR2dVVup VlE/4Gam967KsVjJLn0Fu/qzy6YJN9Yr0Q5evwXDszMWNJEvMJw3QlskAgwNCY2EFk Iseg5vEt3u8BEo/HomXMNr898X5NZa5MyeDxNtAc0+zkikxNn8pr5OzYqe4hpQMgUg Rur9PWkWnovcRb0AprxKxLrQuqv134C0XE25olExO4IvXXpMH/as6qS5oLU9O53Nz5 oEGztC33klKlw== From: Sasha Levin To: stable@vger.kernel.org Cc: Johan Hovold , Greg Kroah-Hartman , Sasha Levin Subject: [PATCH 6.12.y] USB: serial: cypress_m8: fix memory corruption with small endpoint Date: Thu, 4 Jun 2026 09:55:02 -0400 Message-ID: <20260604135502.3494174-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026060436-tubby-pancreas-41ef@gregkh> References: <2026060436-tubby-pancreas-41ef@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Johan Hovold [ Upstream commit e1a9d791fd66ab2431b9e6f6f835823809869047 ] Make sure that the interrupt-out endpoint max packet size is at least eight bytes to avoid user-controlled slab corruption or NULL-pointer dereference should a malicious device report a smaller size. Fixes: 3416eaa1f8f8 ("USB: cypress_m8: Packet format is separate from characteristic size") Cc: stable@vger.kernel.org # 2.6.26 Reviewed-by: Greg Kroah-Hartman Signed-off-by: Johan Hovold Signed-off-by: Sasha Levin --- drivers/usb/serial/cypress_m8.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/usb/serial/cypress_m8.c b/drivers/usb/serial/cypress_m8.c index e29569d65991b3..53f27dee35e6bc 100644 --- a/drivers/usb/serial/cypress_m8.c +++ b/drivers/usb/serial/cypress_m8.c @@ -445,6 +445,14 @@ static int cypress_generic_port_probe(struct usb_serial_port *port) return -ENODEV; } + /* + * The buffer must be large enough for the one or two-byte header (and + * following data), but assume anything smaller than eight bytes is + * broken. + */ + if (port->interrupt_out_size < 8) + return -EINVAL; + priv = kzalloc(sizeof(struct cypress_private), GFP_KERNEL); if (!priv) return -ENOMEM; -- 2.53.0