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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5EEDBC00140 for ; Wed, 10 Aug 2022 11:46:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229782AbiHJLqD (ORCPT ); Wed, 10 Aug 2022 07:46:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43470 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229628AbiHJLqD (ORCPT ); Wed, 10 Aug 2022 07:46:03 -0400 Received: from mail-pj1-x1030.google.com (mail-pj1-x1030.google.com [IPv6:2607:f8b0:4864:20::1030]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 20A775C953; Wed, 10 Aug 2022 04:46:02 -0700 (PDT) Received: by mail-pj1-x1030.google.com with SMTP id q7-20020a17090a7a8700b001f300db8677so1838133pjf.5; Wed, 10 Aug 2022 04:46:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to:from :subject:cc:to:message-id:date:from:to:cc; bh=ei1ljbOBBQBSPmSvzrg9QAdPpWtXbrDjFPAODhjUGRU=; b=nnYLI9q9ypTlhyS+QqNTEzY0nsk0KbZnJoUAEnjHOgB3VlOLXiPH4zGFOwybvU3y/c PtjfQZtMfk48L29BZKe/Kyr/b0dxzTMJID2NvRl6YtSR/ui+LbxWXLpwFrZwwcsVQPzS XGM694O9W3ocM+xy9zmJor7U91uvUsvEaS/qRV0wGanE/4y/KkQsLFOw5CZ/NkJ+9WRQ J9jm9AUXp0C+k8Sh81dsgsCfzRTjRBu4TytqisfoyfTHps2QVtdBL0uny3XKC55V+PyT 0wi/1meO1LP+pcD0X7h2zhk7lgFLBX5XDNpmxeYto7Z2bTp7CD7w4IsDmezUZCWCg2Oy +gSg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to:from :subject:cc:to:message-id:date:x-gm-message-state:from:to:cc; bh=ei1ljbOBBQBSPmSvzrg9QAdPpWtXbrDjFPAODhjUGRU=; b=KP08BlYfiQJSLLBGjhONqvGWKsWhUJLwKvXRvs1MDFzl67dkEHkcaBKP6N+DsxQBCO ze+pVtOS5PGXGiUGDADJs4l04FjaaFzqwt06xv1nh8iY7MLqNSlwHuqgXdW6nQ1jsgUS sIbs8KeXd+srcRGMkVvcg/wmHLya1mZk4s7SbMh+eM3BsoVvlawttb9bKgTcQePNmK2t ZeAOVMck+oPaHwsn1jIOHdn7NdlKKHLTuTHf+eWD2TL6DhGpTWhB+q482zLW4MMxTo7I NnLJ1MmC9HlZj9nVM65soy4A4ScugfSJL88AlsoG6+7k+6wgAjfDqH5pS7p8el/vEIAQ U6Zw== X-Gm-Message-State: ACgBeo096dHKAwJBrFysFzZsFqK4/0lJ1ZJ2IvVXQhuMOC9jyI+i/nA9 awCpnb4YOSi+LU/OkVH20Q== X-Google-Smtp-Source: AA6agR7VtaMkCxIfKdLmKiHOns2CVnpwhFlkABxv/J4LgWQlhoT554XdWQxiS/18TXDdHpvMKxb9wQ== X-Received: by 2002:a17:90b:4a0a:b0:1f4:e4fc:91d3 with SMTP id kk10-20020a17090b4a0a00b001f4e4fc91d3mr3300479pjb.67.1660131961540; Wed, 10 Aug 2022 04:46:01 -0700 (PDT) Received: from localhost ([240d:1a:c0d:9f00:4f2f:926a:23dd:8588]) by smtp.gmail.com with ESMTPSA id x2-20020aa79a42000000b0052e0b928c3csm1712112pfj.219.2022.08.10.04.45.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 10 Aug 2022 04:46:01 -0700 (PDT) Date: Wed, 10 Aug 2022 20:45:56 +0900 (JST) Message-Id: <20220810.204556.441522765735488771.shigeru.yoshida@gmail.com> To: mst@redhat.com, jasowang@redhat.com, axboe@kernel.dk Cc: pbonzini@redhat.com, stefanha@redhat.com, virtualization@lists.linux-foundation.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, shigeru.yoshida@gmail.com Subject: Re: [PATCH] virtio-blk: Avoid use-after-free on suspend/resume From: Shigeru Yoshida In-Reply-To: <20220731070951.196831-1-shigeru.yoshida@gmail.com> References: <20220731070951.196831-1-shigeru.yoshida@gmail.com> X-Mailer: Mew version 6.8 on Emacs 28.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org ping? On Sun, 31 Jul 2022 16:09:51 +0900, Shigeru Yoshida wrote: > hctx->user_data is set to vq in virtblk_init_hctx(). However, vq is > freed on suspend and reallocated on resume. So, hctx->user_data is > invalid after resume, and it will cause use-after-free accessing which > will result in the kernel crash something like below: > > [ 22.428391] Call Trace: > [ 22.428899] > [ 22.429339] virtqueue_add_split+0x3eb/0x620 > [ 22.430035] ? __blk_mq_alloc_requests+0x17f/0x2d0 > [ 22.430789] ? kvm_clock_get_cycles+0x14/0x30 > [ 22.431496] virtqueue_add_sgs+0xad/0xd0 > [ 22.432108] virtblk_add_req+0xe8/0x150 > [ 22.432692] virtio_queue_rqs+0xeb/0x210 > [ 22.433330] blk_mq_flush_plug_list+0x1b8/0x280 > [ 22.434059] __blk_flush_plug+0xe1/0x140 > [ 22.434853] blk_finish_plug+0x20/0x40 > [ 22.435512] read_pages+0x20a/0x2e0 > [ 22.436063] ? folio_add_lru+0x62/0xa0 > [ 22.436652] page_cache_ra_unbounded+0x112/0x160 > [ 22.437365] filemap_get_pages+0xe1/0x5b0 > [ 22.437964] ? context_to_sid+0x70/0x100 > [ 22.438580] ? sidtab_context_to_sid+0x32/0x400 > [ 22.439979] filemap_read+0xcd/0x3d0 > [ 22.440917] xfs_file_buffered_read+0x4a/0xc0 > [ 22.441984] xfs_file_read_iter+0x65/0xd0 > [ 22.442970] __kernel_read+0x160/0x2e0 > [ 22.443921] bprm_execve+0x21b/0x640 > [ 22.444809] do_execveat_common.isra.0+0x1a8/0x220 > [ 22.446008] __x64_sys_execve+0x2d/0x40 > [ 22.446920] do_syscall_64+0x37/0x90 > [ 22.447773] entry_SYSCALL_64_after_hwframe+0x63/0xcd > > This patch fixes this issue by getting vq from vblk, and removes > virtblk_init_hctx(). > > Signed-off-by: Shigeru Yoshida > --- > drivers/block/virtio_blk.c | 24 ++++++++++-------------- > 1 file changed, 10 insertions(+), 14 deletions(-) > > diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c > index 6fc7850c2b0a..d756423e0059 100644 > --- a/drivers/block/virtio_blk.c > +++ b/drivers/block/virtio_blk.c > @@ -101,6 +101,14 @@ static inline blk_status_t virtblk_result(struct virtblk_req *vbr) > } > } > > +static inline struct virtio_blk_vq *get_virtio_blk_vq(struct blk_mq_hw_ctx *hctx) > +{ > + struct virtio_blk *vblk = hctx->queue->queuedata; > + struct virtio_blk_vq *vq = &vblk->vqs[hctx->queue_num]; > + > + return vq; > +} > + > static int virtblk_add_req(struct virtqueue *vq, struct virtblk_req *vbr) > { > struct scatterlist hdr, status, *sgs[3]; > @@ -416,7 +424,7 @@ static void virtio_queue_rqs(struct request **rqlist) > struct request *requeue_list = NULL; > > rq_list_for_each_safe(rqlist, req, next) { > - struct virtio_blk_vq *vq = req->mq_hctx->driver_data; > + struct virtio_blk_vq *vq = get_virtio_blk_vq(req->mq_hctx); > bool kick; > > if (!virtblk_prep_rq_batch(req)) { > @@ -837,7 +845,7 @@ static void virtblk_complete_batch(struct io_comp_batch *iob) > static int virtblk_poll(struct blk_mq_hw_ctx *hctx, struct io_comp_batch *iob) > { > struct virtio_blk *vblk = hctx->queue->queuedata; > - struct virtio_blk_vq *vq = hctx->driver_data; > + struct virtio_blk_vq *vq = get_virtio_blk_vq(hctx); > struct virtblk_req *vbr; > unsigned long flags; > unsigned int len; > @@ -862,22 +870,10 @@ static int virtblk_poll(struct blk_mq_hw_ctx *hctx, struct io_comp_batch *iob) > return found; > } > > -static int virtblk_init_hctx(struct blk_mq_hw_ctx *hctx, void *data, > - unsigned int hctx_idx) > -{ > - struct virtio_blk *vblk = data; > - struct virtio_blk_vq *vq = &vblk->vqs[hctx_idx]; > - > - WARN_ON(vblk->tag_set.tags[hctx_idx] != hctx->tags); > - hctx->driver_data = vq; > - return 0; > -} > - > static const struct blk_mq_ops virtio_mq_ops = { > .queue_rq = virtio_queue_rq, > .queue_rqs = virtio_queue_rqs, > .commit_rqs = virtio_commit_rqs, > - .init_hctx = virtblk_init_hctx, > .complete = virtblk_request_done, > .map_queues = virtblk_map_queues, > .poll = virtblk_poll, > -- > 2.37.1 >