From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 15267C10F27 for ; Tue, 10 Mar 2020 17:53:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CBE2021927 for ; Tue, 10 Mar 2020 17:53:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="NOVgMyD+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726526AbgCJRxg (ORCPT ); Tue, 10 Mar 2020 13:53:36 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:50074 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726283AbgCJRxg (ORCPT ); Tue, 10 Mar 2020 13:53:36 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=gsJiXKDgdx64keYqd+C7ZzwTP0EJv9K9edm2pSAF9ic=; b=NOVgMyD+Bsw2VXMFGBZZqz0e2S ngtOqp8pFH0vehs7/K3Fki0V964X3U+ITmYE2h0ibVHVAMuvX2/quaaNwVT/Zajw2W7baYyOwj/kA 3z6vMvGa6RhJtrfe6QkKOiq2nd3u9jQgPKUrEah66VcGMaJjo0J2kNNb+QRqWP/8tFlLmrksBUIu3 sOuDQfsHyIlXMMwpZqfrKzSoXeoM1m7nYEDB4gSrX7ipBsghAe0MbB7iFKAMOKgjkJ61kiKEuMClS ZiERpsm54ufMveiCQR1Co5QerfTACR0Ha/4EzZxT+YFgmm8LlemHovWWZdl2EbhoAc+RBEIf2I0kK jUXKy3jw==; Received: from hch by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jBj4K-0002b3-Qh; Tue, 10 Mar 2020 17:53:28 +0000 Date: Tue, 10 Mar 2020 10:53:28 -0700 From: Christoph Hellwig To: Prabhath Sajeepa Cc: kbusch@kernel.org, axboe@fb.com, hch@lst.de, sagi@grimberg.me, linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, roland@purestorage.com Subject: Re: [PATCH] nvme-rdma: Avoid double freeing of async event data Message-ID: <20200310175328.GA9203@infradead.org> References: <1583788073-39681-1-git-send-email-psajeepa@purestorage.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1583788073-39681-1-git-send-email-psajeepa@purestorage.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 09, 2020 at 03:07:53PM -0600, Prabhath Sajeepa wrote: > The timeout of identify cmd, which is invoked as part of admin queue > creation, can result in freeing of async event data both in > nvme_rdma_timeout handler and error handling path of > nvme_rdma_configure_admin queue thus causing NULL pointer reference. > Call Trace: > ? nvme_rdma_setup_ctrl+0x223/0x800 [nvme_rdma] > nvme_rdma_create_ctrl+0x2ba/0x3f7 [nvme_rdma] > nvmf_dev_write+0xa54/0xcc6 [nvme_fabrics] > __vfs_write+0x1b/0x40 > vfs_write+0xb2/0x1b0 > ksys_write+0x61/0xd0 > __x64_sys_write+0x1a/0x20 > do_syscall_64+0x60/0x1e0 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > Signed-off-by: Prabhath Sajeepa > Reviewed-by: Roland Dreier This looks good as a hot fix: Reviewed-by: Christoph Hellwig But I really think we need to do something about init vs timeout in the state machine. Otherwise we're going to deal with racing resource deallocation forever.