From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f182.google.com (mail-pl1-f182.google.com [209.85.214.182]) (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 53DEC3AF64F for ; Mon, 6 Jul 2026 17:34:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783359294; cv=none; b=WMUIvNKDK7gOehRZ0janwJS7460lRdAW1VA/5Oz3hCAjHJtG2rmSCpfrhdfXDfnUGtSk2zcsY4oJYcbnPVhhZWLnYUukbC5fIovbce2BabDn5daM9JU3H5q3FT7B54x1YrHz0/WVQFar4ljCvVpxWMQHfnBcyT1Z0Lpcg4csAEo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783359294; c=relaxed/simple; bh=GnGbPIB5vEGoh2+MT7DSP3FGysI2pjlO2rdd5C1mpW4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=JUI1QRUlcmqNxzrvcoNWRqQ0BCaptV30hQUWwZco4u9l55lWxUsAIXsSrBftkNBnQV3F6QSG3IL04HTl3p0q+Ilh6HKF9ncj0I2u9ZBqSdAOFBvhwR98l+j7hjegCHr4U303xB1upsj3jKsqrN/+FuU0NMl6Gcqd8FlvWJfmdnU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=q+PzQfMb; arc=none smtp.client-ip=209.85.214.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="q+PzQfMb" Received: by mail-pl1-f182.google.com with SMTP id d9443c01a7336-2c9b1edf2bdso39715345ad.1 for ; Mon, 06 Jul 2026 10:34:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1783359293; x=1783964093; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=sP4hw4x9wC/jfaZoTNoWPTTQPTkbv3TV+M54+z0unKM=; b=q+PzQfMb4hYtRrFE6dR9Orgzcb9tOfNyttSOkTOh7nD0HLSAZ+vA12KKP4fzbGhJhy Op9IFOPRMbHqQwuxqBcAsYmkQDTadMu2omWLeO2pt+Ye42JMTw+TQHhLAqfJc3mOY2Oj wzkb1XBs/GKee3nJzVurNkDsHqGosjhnWwhvSEyIsmb3pq+Ywf9MM0k1pzR3EbXx9t3z bJlKkJeyVqPRjfsA2sbUkNIqkOyY6tSJB5R7z7lOvs8AX7MA3vlHI9TmEDleLvy0feCM orlQKU3T9WKrrKep0gKYega5s8s7D31ZUAAeica5sDQTGVF2xCZ1GMQVvkCjEP9Pnz8y QLQA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1783359293; x=1783964093; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=sP4hw4x9wC/jfaZoTNoWPTTQPTkbv3TV+M54+z0unKM=; b=NoiREWcjyyqq1T6YS2U9P0eCTl5hf56dx7AkvKyTssyZ72sr/VGFaPQu0kwJKId0pF KY/ZccFjWRrQK+E2aV58hXLNc1qT08U8SxEdsNrHlC6DmW5x/4GDABw3jtNeF4E4bNNI 9uKeD/gj0rhqAalWBt8QdWrjLxyo759KUHCvLm5w8mTPA2Ozq92QOMkCp2Yx4e1Vv94i 56iHFNP3hX+RxrJjg3iSk/D8JQmrTOIgADOBth3afBiEemQlDPf0PzwFcSpR8IOWH0w4 cuMmRx2ONMW+lkWGNWQKIJ/MlajgOO78szdkP/X5W8UpSA2aF2A/YaEJn0I1QDBvgy+V Hwrw== X-Gm-Message-State: AOJu0YwG8ylSOOJtGyidGxNw67Ne7obWQGbZwHGe6qjjKd5S2cTsTohL dUgH0B16AcLMQuqPhXXEd+Hx7z3hfyGqDEB5EAoXpvj509edR45qpr2E/fB6cbgrLVI= X-Gm-Gg: AfdE7cmnzwW3DqeYnLhLtDzvm6OaR6JVxLs6D4+aa2Nw/rtvrrfzGu33BTS/0AbSBUm ycT+w04BTXK4xJEFA6p7rRYp49JrkIplYcTpQbTmCJAOwQzMdslFiLmUFFGoySpHXvAff6aavA/ 4b2MoLCROirp/lmWw66i0pcye6TeeW8LGAE22x6mpHSg5Vk030b7p2j7ER0eO/glqt23WqYPxIw 5STvJ3ocijfaE6CAQoAdXFXc1mXrI8euHBnvoAHPtLShvZRpXrNjK3EEqgmceShWkEPy4lS5sZt oxLHqTAWGHRMZ5MR47BIr/s+y7L2m85z7sJ6IozbleSknDNfK9txlQPkeIKAtWR/wDfSmQWro7w ijqXfi4IWFGVqj1jpEANLOYzWtvrz2aXYOWAEBEwWkPQu5n1uZfYJ/f+1qn9Hp5Jdv19MgapWkj EyokraRrnIvKestSOQJ+OrMb1HOMC7uUxdMq5o3uU= X-Received: by 2002:a17:903:3550:b0:2ca:d666:df72 with SMTP id d9443c01a7336-2ccbec1e9f8mr16071265ad.21.1783359292584; Mon, 06 Jul 2026 10:34:52 -0700 (PDT) Received: from naup-virtual-machine ([140.113.139.102]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2cad6f260acsm54803395ad.6.2026.07.06.10.34.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 06 Jul 2026 10:34:52 -0700 (PDT) Date: Tue, 7 Jul 2026 01:34:49 +0800 From: Hao-Yu Yang To: Jens Axboe Cc: linux-kernel@vger.kernel.org, io-uring@vger.kernel.org Subject: Re: [PATCH v1] io_uring: fix dangling iovec after provided-buffer bundle grow failure Message-ID: References: <20260705234534.768138-1-naup96721@gmail.com> <0a370728-f8be-4aaa-bbc6-276376adc5ce@kernel.dk> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Mon, Jul 06, 2026 at 11:13:55AM -0600, Jens Axboe wrote: > On 7/6/26 11:01 AM, Hao-Yu Yang wrote: > > Sorry, i forgot to cc others mail > > > > I discovered and wrote the PoC myself. Trigger way is > > send1: Submit an IORING_OP_SEND request with four valid > > provided buffers. The system will allocate and cache an > > iovec array (of size 4) for this request and store the > > pointer in kmsg->vec.iovec. > > > > send2: Submit a second send request with 8, and I set > > the fourth passed-in address to point to an invalid address. > > Now kmsg still hold old iovec, but old iovec object have > > been freed. > > > > So this will lead dangling pointer. > > Side note: please don't top post, linux mailing lists always reply > under the text for better readability. Top posting turns any kind > of threaded conversation into both a mess, and it's also wasteful. > > Great thanks! Want to turn this into a liburing test case? Then we can > include it there as well, and it'd catch both UAF and memory leaks when > run. > > -- > Jens Axboe How to turn this into a liburing test case? Should this be included in the v2 patch?