From patchwork Thu Apr 27 11:23:35 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dominique Martinet X-Patchwork-Id: 13225387 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D69E9C77B61 for ; Thu, 27 Apr 2023 11:24:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243416AbjD0LYK (ORCPT ); Thu, 27 Apr 2023 07:24:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35446 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243636AbjD0LX7 (ORCPT ); Thu, 27 Apr 2023 07:23:59 -0400 Received: from nautica.notk.org (ipv6.notk.org [IPv6:2001:41d0:1:7a93::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E8B125B86; Thu, 27 Apr 2023 04:23:57 -0700 (PDT) Received: by nautica.notk.org (Postfix, from userid 108) id E3BB0C023; Thu, 27 Apr 2023 13:23:54 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=codewreck.org; s=2; t=1682594634; bh=s+rCY3PhNsjKtAMo7ceBkqmXMZyC1GJyZBLyjIlkj7k=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=BKMeJuqCAs7gz87ccJfjFExzkNjMiSf/Hrt+lG/vd7cp1BFvOaNAKkEYyEe6kvVlZ wv8ZG02JYJpZsejUbhty0V8HrOXCq7QD+xn6lnvLzzrGQqG4RyU+kZqTnssQ43QS0n bPYO4LfxDOPFbfCwuh87fJj9fEL0hb7w9PzQ1aR29UlOW2TIXLC0AoZ5VlU7mDcg7P xWUWuLpe+hlxIpYWp0KtaX9D6aKuBrc3JifIBrNqMcuyaYgIWm59P0iHXG3o3oReIt iVTBzVpY2Vad0a+BXN2E4f9SBwmRVOy3PTeXMwOxs+ICdtnAG77zniLBvvz1xIB/sV I7y4tzwKLz2Qw== Received: from odin.codewreck.org (localhost [127.0.0.1]) by nautica.notk.org (Postfix) with ESMTPS id 11A22C023; Thu, 27 Apr 2023 13:23:47 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=codewreck.org; s=2; t=1682594633; bh=s+rCY3PhNsjKtAMo7ceBkqmXMZyC1GJyZBLyjIlkj7k=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=ZlmRSHYPRZOSAJgH54xjFLq2yzzElppfvubM0NynWTo1tmNsz3qHQbcee2Isz7ceY 3yZTE8Mq4ZakBNtUU3Z8JW+zsI0+DSqJJVDmSRze2XwOiaz+0HAcDpwo0KTz4ZnMRj xW5UpirTNghyfFGznRoDpDfSKqDBV2VG2eF9WPOaZmZ30IJK7qBPrJQKZsZ1nF6GSz IITwI9V4yauR7QtwkL+88D1Cch00cRg2I1Bhoy4I7JswnvdZfWwu2WwaGvRqhzlXWj PjOvZbgBLlASMztmYMZkMIa79mkCUofMCdEtLZ79Kry7mT13q2+X5bK367zWB7+Bpu aJPlWpR7W1OgA== Received: from [127.0.0.2] (localhost [::1]) by odin.codewreck.org (OpenSMTPD) with ESMTP id 224b0460; Thu, 27 Apr 2023 11:23:38 +0000 (UTC) From: Dominique Martinet Date: Thu, 27 Apr 2023 20:23:35 +0900 Subject: [PATCH 2/5] 9p: virtio: fix unlikely null pointer deref in handle_rerror MIME-Version: 1.0 Message-Id: <20230427-scan-build-v1-2-efa05d65e2da@codewreck.org> References: <20230427-scan-build-v1-0-efa05d65e2da@codewreck.org> In-Reply-To: <20230427-scan-build-v1-0-efa05d65e2da@codewreck.org> To: Eric Van Hensbergen , Latchesar Ionkov , Christian Schoenebeck , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: v9fs@lists.linux.dev, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Dominique Martinet X-Mailer: b4 0.13-dev-f371f X-Developer-Signature: v=1; a=openpgp-sha256; l=1336; i=asmadeus@codewreck.org; h=from:subject:message-id; bh=uAxOy5RN+SshQ0IlB7WUwAUYTCBMSrvtKIu4Ytp0HO8=; b=owEBbQKS/ZANAwAIAatOm+xqmOZwAcsmYgBkSls6sv0W5uY/qDr+rJzbHgv/8wIRfEH4Mb226 8L3vvejGgOJAjMEAAEIAB0WIQT8g9txgG5a3TOhiE6rTpvsapjmcAUCZEpbOgAKCRCrTpvsapjm cIY9D/sG6txif6f/ao9Jzx0NwqwbUftDmaENl23wBkDzshsr8eDrKr1JyNsvgNIy0v6ToBG4q+1 aQ80V4X+/VM0nOAJ+fynVm4z21W1K2oNfgXRTdYzERfDUMkSPlzuiowECY/hJzeyFSoqyNaAFGW 1lHtKoo6hdOmG9Wgr/0GmRXtQUYk+SXyl0fOX7et/7ASmTSv8XSZtazNY3FNX1SiFotyIJ7rxN+ +TqIuai/zi4c/PeFTzOIUUUoTLUJYKleI0dMED7bGvTY1l4wqftWD15r76gcjO1zzbkFgrFn9DN vu8Srzkh7Ctmrw1aJR7p+ot7WeHZgD4sxxXcbySpZ24ziw4RRgaJuVd5HZsJ7fTuYwRNILXEfZD u3Yji+B2kJJqDi1PV6gn/9T9EbH8ftvqzUB7J8EU93kLbq/n4wF+trJoFD3FQAOt9LBP5ry+U/y KjdBLGKFgJGY1tpkOV+XXZnUCktQooqA2IH1zQNntrsjVfVujlYEnRRqVRbL/Ybj9S4qNEyAehQ SVVCiT9T9SXz+1h6t3lZU6RMrLPOtZq9qbKNmP8lQUJGUx2grjFs6GbSQfGjKvLVsBI9PqTqJ7l it7pKb4GSLaR56oan4Iy1BYy/bbGYcwxYbTmW73ZrahU5hD+KECcXRm3ORCS59QGNxiNtvY0pus ibuiffORyhotsvg== X-Developer-Key: i=asmadeus@codewreck.org; a=openpgp; fpr=B894379F662089525B3FB1B9333F1F391BBBB00A Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org handle_rerror can dereference the pages pointer, but it is not necessarily set for small payloads. In practice these should be filtered out by the size check, but might as well double-check explicitly. This fixes the following scan-build warnings: net/9p/trans_virtio.c:401:24: warning: Dereference of null pointer [core.NullDereference] memcpy_from_page(to, *pages++, offs, n); ^~~~~~~~ net/9p/trans_virtio.c:406:23: warning: Dereference of null pointer (loaded from variable 'pages') [core.NullDereference] memcpy_from_page(to, *pages, offs, size); ^~~~~~ Signed-off-by: Dominique Martinet Reviewed-by: Simon Horman --- net/9p/trans_virtio.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c index 3c27ffb781e3..2c9495ccda6b 100644 --- a/net/9p/trans_virtio.c +++ b/net/9p/trans_virtio.c @@ -384,7 +384,7 @@ static void handle_rerror(struct p9_req_t *req, int in_hdr_len, void *to = req->rc.sdata + in_hdr_len; // Fits entirely into the static data? Nothing to do. - if (req->rc.size < in_hdr_len) + if (req->rc.size < in_hdr_len || !pages) return; // Really long error message? Tough, truncate the reply. Might get