From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 62934A2C for ; Mon, 14 Feb 2022 17:51:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1644861105; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=sRClfikrb2SAycFi2aWUxJvEEU6PW+e2USfmkK1Iaug=; b=XviSr68nOxrbdbennGxQQjQrypAOLEhW1qkIVujCa3be2lxAAZhSJtwybSZbnb9AGt6Qce VlVx+oz36hig08c9Kd9jfiePd1rYBSETCMn//ISFiL0Yu27IUqrAQnnS13e2W8zSYO71EZ pcnPaoPWi+MTHGOMHnZj99L3VOYy824= Received: from mail-oo1-f71.google.com (mail-oo1-f71.google.com [209.85.161.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-64-HtdiNVVpPOCOKnsq9MuBAA-1; Mon, 14 Feb 2022 12:51:44 -0500 X-MC-Unique: HtdiNVVpPOCOKnsq9MuBAA-1 Received: by mail-oo1-f71.google.com with SMTP id g8-20020a4aa708000000b002e8efc514a6so11010784oom.12 for ; Mon, 14 Feb 2022 09:51:43 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=sRClfikrb2SAycFi2aWUxJvEEU6PW+e2USfmkK1Iaug=; b=1HJO0uFzAThrkyMAPiuj8pcCZlaxUJSETal3BuDq+m5klGYXon/VbkjY/i2V3R52ZQ C2IC5/SPfYGinfnGbmRPGU+qUjESdSygqeRnf67DNLLWjUVLhJ1zg2SUdx3GNi/Sj+FZ +xSiU3qcCreyazXIhV5CMWB6CNCv9Fzz5BRhZD3+THVQ4Z03c2dKgPUBRzggqOIw2S9T Nv3vxdeCZXQCTs+YTOmeKrlU/jUFKqPASFhONIGEyYkiCM48v8VIrpJqYsVZk8nKXw9v fFPetcgffLxGdoYSsr/HX6OaJYFdx0oF6xWkwB158ZMg4Dh9TBG8Av5V6KoyvaSe8Pl1 ykyw== X-Gm-Message-State: AOAM532PedYFidM/eXz5PYTu0qVoaD5d9EK2Jyz615x4I0TpyekvzFBG 6/KqX2gxZKNkI25aETLWQhn+bWT4R/v9wQNTodMqn6tJDkXTWGSVdPPuH5f3MltdQc170UAb/ux +HuOEC6rxuRPyBA== X-Received: by 2002:a9d:6e84:: with SMTP id a4mr18934otr.43.1644861103174; Mon, 14 Feb 2022 09:51:43 -0800 (PST) X-Google-Smtp-Source: ABdhPJzcnHxTDhHzI4mHvMfEWEZ41qbHYDvsaNz05h/swvvbijMzbRD2lKpXlDtrTUoDdBuBcdn0Yg== X-Received: by 2002:a9d:6e84:: with SMTP id a4mr18930otr.43.1644861102975; Mon, 14 Feb 2022 09:51:42 -0800 (PST) Received: from localhost.localdomain.com (024-205-208-113.res.spectrum.com. [24.205.208.113]) by smtp.gmail.com with ESMTPSA id w20sm12910024ooe.3.2022.02.14.09.51.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 14 Feb 2022 09:51:42 -0800 (PST) From: trix@redhat.com To: jk@codeconstruct.com.au, matt@codeconstruct.com.au, davem@davemloft.net, kuba@kernel.org, nathan@kernel.org, ndesaulniers@google.com Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev, Tom Rix Subject: [PATCH] mctp: fix use after free Date: Mon, 14 Feb 2022 09:51:38 -0800 Message-Id: <20220214175138.2902947-1-trix@redhat.com> X-Mailer: git-send-email 2.26.3 Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=trix@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="US-ASCII" From: Tom Rix Clang static analysis reports this problem route.c:425:4: warning: Use of memory after it is freed trace_mctp_key_acquire(key); ^~~~~~~~~~~~~~~~~~~~~~~~~~~ When mctp_key_add() fails, key is freed but then is later used in trace_mctp_key_acquire(). Add an else statement to use the key only when mctp_key_add() is successful. Fixes: 4a992bbd3650 ("mctp: Implement message fragmentation & reassembly") Signed-off-by: Tom Rix --- net/mctp/route.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/net/mctp/route.c b/net/mctp/route.c index 17e3482aa770..0c4c56e1bd6e 100644 --- a/net/mctp/route.c +++ b/net/mctp/route.c @@ -419,13 +419,14 @@ static int mctp_route_input(struct mctp_route *route, struct sk_buff *skb) * this function. */ rc = mctp_key_add(key, msk); - if (rc) + if (rc) { kfree(key); + } else { + trace_mctp_key_acquire(key); - trace_mctp_key_acquire(key); - - /* we don't need to release key->lock on exit */ - mctp_key_unref(key); + /* we don't need to release key->lock on exit */ + mctp_key_unref(key); + } key = NULL; } else { -- 2.26.3