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 4F9D9C04A95 for ; Wed, 28 Sep 2022 03:34:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231986AbiI1DeQ (ORCPT ); Tue, 27 Sep 2022 23:34:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45350 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231642AbiI1DeM (ORCPT ); Tue, 27 Sep 2022 23:34:12 -0400 Received: from mail-m974.mail.163.com (mail-m974.mail.163.com [123.126.97.4]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 08C6F11CB13 for ; Tue, 27 Sep 2022 20:34:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:Subject:Date:Message-Id:MIME-Version; bh=ByRr8 bZsJJi4I3/qCoEvNPxs2sr+s2xR5n1KueAfAZY=; b=nHH/YhXlV8qTBLS06GksC VVv88TpJlSV0HA5IxK404/vcj/p5QzXXjdye/kN76XOWgfDbk1+SLWK7ls4wPAku k9d/2YhYM3p7Wr/SAWJUeYZxS7OLxS2gTobh2Uvxkfrrj9sgGz2e6m7nW8XW+4Wh Tlcj1TGHTOxf6x8/756Cp4= Received: from leanderwang-LC2.localdomain (unknown [111.206.145.21]) by smtp4 (Coremail) with SMTP id HNxpCgCXvdGUwDNj9OqbgQ--.9697S2; Wed, 28 Sep 2022 11:33:41 +0800 (CST) From: Zheng Wang To: hackerzheng666@gmail.com Cc: 1002992920@qq.com, airlied@linux.ie, alex000young@gmail.com, dri-devel@lists.freedesktop.org, gregkh@linuxfoundation.org, intel-gfx@lists.freedesktop.org, jani.nikula@linux.intel.com, linux-kernel@vger.kernel.org, security@kernel.org, tvrtko.ursulin@linux.intel.com, Zheng Wang Subject: [PATCH] drm/i915/gvt: fix double free bug in split_2MB_gtt_entry Date: Wed, 28 Sep 2022 11:33:40 +0800 Message-Id: <20220928033340.1063949-1-zyytlz.wz@163.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID: HNxpCgCXvdGUwDNj9OqbgQ--.9697S2 X-Coremail-Antispam: 1Uf129KBjvJXoWxJFWrCw4kCrW7ZF15Ar1DKFg_yoW5WF4fpF W5Xa1qyFs5A3y2vF47Aa1kZF15AF1fury8Gr93K3ZayF1DtF1ktFZ8XFW3Wrya9FZ7Gr1f Ar4UtFW7Cay7XaDanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x0zRDGYJUUUUU= X-Originating-IP: [111.206.145.21] X-CM-SenderInfo: h2113zf2oz6qqrwthudrp/xtbCqQOKU10DhE6moAAAsh Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If intel_gvt_dma_map_guest_page failed, it will call ppgtt_invalidate_spt, which will finally free the spt. But the caller does not notice that, it will free spt again in error path. Fix this by only freeing spt in ppgtt_invalidate_spt in good case. Fixes: b901b252b6cf ("drm/i915/gvt: Add 2M huge gtt support") Reported-by: Zheng Wang Signed-off-by: Zheng Wang --- drivers/gpu/drm/i915/gvt/gtt.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/i915/gvt/gtt.c b/drivers/gpu/drm/i915/gvt/gtt.c index ce0eb03709c3..550519f0acca 100644 --- a/drivers/gpu/drm/i915/gvt/gtt.c +++ b/drivers/gpu/drm/i915/gvt/gtt.c @@ -959,7 +959,7 @@ static inline int ppgtt_put_spt(struct intel_vgpu_ppgtt_spt *spt) return atomic_dec_return(&spt->refcount); } -static int ppgtt_invalidate_spt(struct intel_vgpu_ppgtt_spt *spt); +static int ppgtt_invalidate_spt(struct intel_vgpu_ppgtt_spt *spt, int is_error); static int ppgtt_invalidate_spt_by_shadow_entry(struct intel_vgpu *vgpu, struct intel_gvt_gtt_entry *e) @@ -995,7 +995,7 @@ static int ppgtt_invalidate_spt_by_shadow_entry(struct intel_vgpu *vgpu, ops->get_pfn(e)); return -ENXIO; } - return ppgtt_invalidate_spt(s); + return ppgtt_invalidate_spt(s, 0); } static inline void ppgtt_invalidate_pte(struct intel_vgpu_ppgtt_spt *spt, @@ -1016,7 +1016,7 @@ static inline void ppgtt_invalidate_pte(struct intel_vgpu_ppgtt_spt *spt, intel_gvt_dma_unmap_guest_page(vgpu, pfn << PAGE_SHIFT); } -static int ppgtt_invalidate_spt(struct intel_vgpu_ppgtt_spt *spt) +static int ppgtt_invalidate_spt(struct intel_vgpu_ppgtt_spt *spt, int is_error) { struct intel_vgpu *vgpu = spt->vgpu; struct intel_gvt_gtt_entry e; @@ -1059,9 +1059,11 @@ static int ppgtt_invalidate_spt(struct intel_vgpu_ppgtt_spt *spt) } } - trace_spt_change(spt->vgpu->id, "release", spt, + if (!is_error) { + trace_spt_change(spt->vgpu->id, "release", spt, spt->guest_page.gfn, spt->shadow_page.type); - ppgtt_free_spt(spt); + ppgtt_free_spt(spt); + } return 0; fail: gvt_vgpu_err("fail: shadow page %p shadow entry 0x%llx type %d\n", @@ -1215,7 +1217,7 @@ static int split_2MB_gtt_entry(struct intel_vgpu *vgpu, ret = intel_gvt_dma_map_guest_page(vgpu, start_gfn + sub_index, PAGE_SIZE, &dma_addr); if (ret) { - ppgtt_invalidate_spt(spt); + ppgtt_invalidate_spt(spt, 1); return ret; } sub_se.val64 = se->val64; @@ -1393,7 +1395,7 @@ static int ppgtt_handle_guest_entry_removal(struct intel_vgpu_ppgtt_spt *spt, ret = -ENXIO; goto fail; } - ret = ppgtt_invalidate_spt(s); + ret = ppgtt_invalidate_spt(s, 0); if (ret) goto fail; } else { -- 2.25.1