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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 AF348C4332E for ; Wed, 10 Mar 2021 13:30:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 66FC66505D for ; Wed, 10 Mar 2021 13:30:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234215AbhCJNaD (ORCPT ); Wed, 10 Mar 2021 08:30:03 -0500 Received: from mail.kernel.org ([198.145.29.99]:47566 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233433AbhCJNZg (ORCPT ); Wed, 10 Mar 2021 08:25:36 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 45DA1650BA; Wed, 10 Mar 2021 13:25:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1615382735; bh=P42BTBuOaK6KxmIvSYogVcZ03l62cJNGYZRi0d8y5/4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gJaUzTqaCHf5e3yr4dxVHgP9OJaUMC25mcVxui9frf++rDn8It1ksrdFJ/BkHcwK5 HEizTqBWvGmn46iNLV3cHTDA8x8qRp3eYRO8yigtdyEi2kNulu42lpMZAYwI3DS5iz K5lHSGP8jf+2sbhk5QY5uBLhUlGGDrAEcpJ+J5Sc= From: gregkh@linuxfoundation.org To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andrey Ryabinin , Will Deacon , Joerg Roedel Subject: [PATCH 4.19 25/39] iommu/amd: Fix sleeping in atomic in increase_address_space() Date: Wed, 10 Mar 2021 14:24:33 +0100 Message-Id: <20210310132320.508004506@linuxfoundation.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210310132319.708237392@linuxfoundation.org> References: <20210310132319.708237392@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Greg Kroah-Hartman From: Andrey Ryabinin commit 140456f994195b568ecd7fc2287a34eadffef3ca upstream. increase_address_space() calls get_zeroed_page(gfp) under spin_lock with disabled interrupts. gfp flags passed to increase_address_space() may allow sleeping, so it comes to this: BUG: sleeping function called from invalid context at mm/page_alloc.c:4342 in_atomic(): 1, irqs_disabled(): 1, pid: 21555, name: epdcbbf1qnhbsd8 Call Trace: dump_stack+0x66/0x8b ___might_sleep+0xec/0x110 __alloc_pages_nodemask+0x104/0x300 get_zeroed_page+0x15/0x40 iommu_map_page+0xdd/0x3e0 amd_iommu_map+0x50/0x70 iommu_map+0x106/0x220 vfio_iommu_type1_ioctl+0x76e/0x950 [vfio_iommu_type1] do_vfs_ioctl+0xa3/0x6f0 ksys_ioctl+0x66/0x70 __x64_sys_ioctl+0x16/0x20 do_syscall_64+0x4e/0x100 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fix this by moving get_zeroed_page() out of spin_lock/unlock section. Fixes: 754265bcab ("iommu/amd: Fix race in increase_address_space()") Signed-off-by: Andrey Ryabinin Acked-by: Will Deacon Cc: Link: https://lore.kernel.org/r/20210217143004.19165-1-arbn@yandex-team.com Signed-off-by: Joerg Roedel Signed-off-by: Andrey Ryabinin Signed-off-by: Greg Kroah-Hartman --- drivers/iommu/amd_iommu.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -1348,24 +1348,26 @@ static void increase_address_space(struc unsigned long flags; u64 *pte; + pte = (void *)get_zeroed_page(gfp); + if (!pte) + return; + spin_lock_irqsave(&domain->lock, flags); if (WARN_ON_ONCE(domain->mode == PAGE_MODE_6_LEVEL)) /* address space already 64 bit large */ goto out; - pte = (void *)get_zeroed_page(gfp); - if (!pte) - goto out; - *pte = PM_LEVEL_PDE(domain->mode, iommu_virt_to_phys(domain->pt_root)); domain->pt_root = pte; domain->mode += 1; domain->updated = true; + pte = NULL; out: spin_unlock_irqrestore(&domain->lock, flags); + free_page((unsigned long)pte); return; }