From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pg1-f170.google.com (mail-pg1-f170.google.com [209.85.215.170]) (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 2987D1D0DF2 for ; Thu, 22 Aug 2024 22:21:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.170 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724365287; cv=none; b=iP5S6b+iKpiEyIVDPWvHxvfkfgOTMANu/Wq8QIM0irKvNwZ6bCP/VE/rSCwyWBRnmJiCIykVqP3BzzDzAG+svmTxD8fW3PBg+bXVgkAob7oix1h7A4X9DjQfCdkPHHMSU7z95sMZDVdHxEk79L/7N/rBtY9DWyHzSI9w181YW4c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724365287; c=relaxed/simple; bh=j8RDWl/MUW9jSpqRoo/6uv4ikq6fPGI3FhR30VRxn9U=; h=Message-ID:Date:MIME-Version:To:From:Subject:Content-Type; b=OFn77eKFhu4kbk4A4WeZQEcFot85DSf+DtrsNn89PGbz7ew8NkkKF6uYNMmAvWzj1GZydwSrjlf87caW+85PLLUU4IdSf7f1BTWLdfuBOXD7xmOGQjEz2v8DshVj4pFES6WY+VrfwaJHn3+auHffUaAlIJS5kDobVQyK5AkArd8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk; spf=pass smtp.mailfrom=kernel.dk; dkim=pass (2048-bit key) header.d=kernel-dk.20230601.gappssmtp.com header.i=@kernel-dk.20230601.gappssmtp.com header.b=xhS+aATn; arc=none smtp.client-ip=209.85.215.170 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kernel.dk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20230601.gappssmtp.com header.i=@kernel-dk.20230601.gappssmtp.com header.b="xhS+aATn" Received: by mail-pg1-f170.google.com with SMTP id 41be03b00d2f7-7c3d9a5e050so964241a12.2 for ; Thu, 22 Aug 2024 15:21:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20230601.gappssmtp.com; s=20230601; t=1724365281; x=1724970081; darn=vger.kernel.org; h=content-transfer-encoding:subject:from:to:content-language :user-agent:mime-version:date:message-id:from:to:cc:subject:date :message-id:reply-to; bh=t92z2/CRXinBKFyyoX01nV8Fbp2TSnPxtNZsBrfXelc=; b=xhS+aATns936FGLZPirj2bKccXRpBK9/6mQmLTyKlIh/nU1ag2NkpLmgtvI9oV8j7H L5eIQIZE8Vk+BvoF1iIaOPcG8k3v0LTTO0RmERlPK1lslltzPrzqik7wXbx0dgfV3qyW tv+EOdI8Gf5c8VPUUO0JKJX1Lc1tvGV0RNXRuuDDt8F40EEJXNPrGUV5Zn17SsbibEEb BXZslb6kjBta3Qdy3FzkCIB0sKqKn6fgpG7Vo2Y7lwBPCTdhIVSa334aX1mBwntuZakn oI4Np3Ur5X68/PDKgPDqvFuJp4IMsuogRRlcT8QYCXah6kEkIgV6KstHiyP0Vf5TkYyW oV+g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1724365281; x=1724970081; h=content-transfer-encoding:subject:from:to:content-language :user-agent:mime-version:date:message-id:x-gm-message-state:from:to :cc:subject:date:message-id:reply-to; bh=t92z2/CRXinBKFyyoX01nV8Fbp2TSnPxtNZsBrfXelc=; b=pTtvGmUrMIiQJoGcqJH7lWEwQBB+v2K4IvWTlu5OzPOjduSIJg1R7pxBBJlAQsssEY SD60kS4TX7QiaQjbOlPDWw4kaAhhKtjbKLpsCdzVcLj4V0TuUmaj912I0euvuCSS2077 T96Yl8nyOnOu+qAbBVb3KvZ84/w4JljyP020z3pzjeqn7G8LYvNvFRV8Pm26uS36SNBf AEILywTCfXEi2ULlJmXf0ZBrS8WEHC+8+aHjKVo2JsX/V5qBRx1SmldYHNETSTEBE5vo NARE0XQ3q60IHnx3pzWqiHhrNhAtlkRb7h/8FTlnuVgjbMW0/bKneOrYIVCDD8CoHGb0 kstw== X-Gm-Message-State: AOJu0YyHEV5vxNLk0HV9bKR9OhdFhSbKcxVs0bq+nz6gs8rQ3247iq3g rpGWoV0wxFDETmdigcIkvxMHFLB2itQQ1h300DmO5T813nr3g8z5v3876cYCm0Nla/vJL+8QrSc r X-Google-Smtp-Source: AGHT+IGIyaRyLaKMdN9FR5VAZM9hLP7m8xRCmVymn7gRx44B1ihodzg+ezRuXPF+M7YO9qblIw0DgA== X-Received: by 2002:a05:6a21:1304:b0:1c3:cfc2:2b1f with SMTP id adf61e73a8af0-1cc8a10db5dmr596848637.37.1724365281306; Thu, 22 Aug 2024 15:21:21 -0700 (PDT) Received: from [192.168.1.150] ([198.8.77.157]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-203855664c1sm17367295ad.3.2024.08.22.15.21.20 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 22 Aug 2024 15:21:20 -0700 (PDT) Message-ID: Date: Thu, 22 Aug 2024 16:21:19 -0600 Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Content-Language: en-US To: io-uring From: Jens Axboe Subject: [PATCH] io_uring/kbuf: sanitize peek buffer setup Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Harden the buffer peeking a bit, by adding a sanity check for it having a valid size. Outside of that, arg->max_len is a size_t, though it's only ever set to a 32-bit value (as it's governed by MAX_RW_COUNT). Bump our needed check to a size_t so we know it fits. Finally, cap the calculated needed iov value to the PEEK_MAX_IMPORT, which is the maximum number of segments that should be peeked. Fixes: 35c8711c8fc4 ("io_uring/kbuf: add helpers for getting/peeking multiple buffers") Signed-off-by: Jens Axboe --- diff --git a/io_uring/kbuf.c b/io_uring/kbuf.c index c95dc1736dd9..1af2bd56af44 100644 --- a/io_uring/kbuf.c +++ b/io_uring/kbuf.c @@ -218,10 +218,13 @@ static int io_ring_buffers_peek(struct io_kiocb *req, struct buf_sel_arg *arg, buf = io_ring_head_to_buf(br, head, bl->mask); if (arg->max_len) { - int needed; + u32 len = READ_ONCE(buf->len); + size_t needed; - needed = (arg->max_len + buf->len - 1) / buf->len; - needed = min(needed, PEEK_MAX_IMPORT); + if (unlikely(!len)) + return -ENOBUFS; + needed = (arg->max_len + len - 1) / len; + needed = min_not_zero(needed, (size_t) PEEK_MAX_IMPORT); if (nr_avail > needed) nr_avail = needed; } -- Jens Axboe