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=-8.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLACK,USER_AGENT_GIT autolearn=unavailable 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 5D01FC2BA83 for ; Fri, 14 Feb 2020 18:39:51 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 04CEF20848 for ; Fri, 14 Feb 2020 18:39:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="BmpIe9OT" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 04CEF20848 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 48K2H767Q4zDqdq for ; Sat, 15 Feb 2020 05:39:47 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=198.145.29.99; helo=mail.kernel.org; envelope-from=sashal@kernel.org; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=kernel.org Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=default header.b=BmpIe9OT; dkim-atps=neutral Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 48Jz1W0c5WzDqYS for ; Sat, 15 Feb 2020 03:12:47 +1100 (AEDT) Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 695E42469B; Fri, 14 Feb 2020 16:12:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581696763; bh=pbVzIndI7U2QKW7IP8oF3dBRt7hGnqAhaZiECsdUCfk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BmpIe9OTvkn7BR6owNLTk0RHtrWH00RFSL3QEf4l4+kcVHO2fMEOJBzSJb4/u7xGO w2EO366ulVDoCSMChVHwaMzpM+SrT1dYzc7kOHJU0Zhv/SyhwDLeUmatVedXraY63r MCnXXFTDyKIOIrDbtcaGLuwhLxI+5yWMUH9lAVtQ= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 043/252] powerpc/pseries/vio: Fix iommu_table use-after-free refcount warning Date: Fri, 14 Feb 2020 11:08:18 -0500 Message-Id: <20200214161147.15842-43-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200214161147.15842-1-sashal@kernel.org> References: <20200214161147.15842-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Sasha Levin , Tyrel Datwyler , Alexey Kardashevskiy , Tyrel Datwyler , linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" From: Tyrel Datwyler [ Upstream commit aff8c8242bc638ba57247ae1ec5f272ac3ed3b92 ] Commit e5afdf9dd515 ("powerpc/vfio_spapr_tce: Add reference counting to iommu_table") missed an iommu_table allocation in the pseries vio code. The iommu_table is allocated with kzalloc and as a result the associated kref gets a value of zero. This has the side effect that during a DLPAR remove of the associated virtual IOA the iommu_tce_table_put() triggers a use-after-free underflow warning. Call Trace: [c0000002879e39f0] [c00000000071ecb4] refcount_warn_saturate+0x184/0x190 (unreliable) [c0000002879e3a50] [c0000000000500ac] iommu_tce_table_put+0x9c/0xb0 [c0000002879e3a70] [c0000000000f54e4] vio_dev_release+0x34/0x70 [c0000002879e3aa0] [c00000000087cfa4] device_release+0x54/0xf0 [c0000002879e3b10] [c000000000d64c84] kobject_cleanup+0xa4/0x240 [c0000002879e3b90] [c00000000087d358] put_device+0x28/0x40 [c0000002879e3bb0] [c0000000007a328c] dlpar_remove_slot+0x15c/0x250 [c0000002879e3c50] [c0000000007a348c] remove_slot_store+0xac/0xf0 [c0000002879e3cd0] [c000000000d64220] kobj_attr_store+0x30/0x60 [c0000002879e3cf0] [c0000000004ff13c] sysfs_kf_write+0x6c/0xa0 [c0000002879e3d10] [c0000000004fde4c] kernfs_fop_write+0x18c/0x260 [c0000002879e3d60] [c000000000410f3c] __vfs_write+0x3c/0x70 [c0000002879e3d80] [c000000000415408] vfs_write+0xc8/0x250 [c0000002879e3dd0] [c0000000004157dc] ksys_write+0x7c/0x120 [c0000002879e3e20] [c00000000000b278] system_call+0x5c/0x68 Further, since the refcount was always zero the iommu_tce_table_put() fails to call the iommu_table release function resulting in a leak. Fix this issue be initilizing the iommu_table kref immediately after allocation. Fixes: e5afdf9dd515 ("powerpc/vfio_spapr_tce: Add reference counting to iommu_table") Signed-off-by: Tyrel Datwyler Reviewed-by: Alexey Kardashevskiy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/1579558202-26052-1-git-send-email-tyreld@linux.ibm.com Signed-off-by: Sasha Levin --- arch/powerpc/platforms/pseries/vio.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/powerpc/platforms/pseries/vio.c b/arch/powerpc/platforms/pseries/vio.c index 49e04ec19238a..0e7778be4c490 100644 --- a/arch/powerpc/platforms/pseries/vio.c +++ b/arch/powerpc/platforms/pseries/vio.c @@ -1195,6 +1195,8 @@ static struct iommu_table *vio_build_iommu_table(struct vio_dev *dev) if (tbl == NULL) return NULL; + kref_init(&tbl->it_kref); + of_parse_dma_window(dev->dev.of_node, dma_window, &tbl->it_index, &offset, &size); -- 2.20.1