From patchwork Tue Apr 5 07:23:21 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 558034 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 04AB7C433EF for ; Tue, 5 Apr 2022 08:23:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234547AbiDEIZl (ORCPT ); Tue, 5 Apr 2022 04:25:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43702 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238435AbiDEITG (ORCPT ); Tue, 5 Apr 2022 04:19:06 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 230B4B84F; Tue, 5 Apr 2022 01:08:53 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id A0522608C0; Tue, 5 Apr 2022 08:08:52 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B0AF5C385A0; Tue, 5 Apr 2022 08:08:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649146132; bh=lLUB6/PLO7CaoHTOodfcqfI4F641Ksv26ccVQ4WLnvA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NCbEYHEVd7RYLFpnJc9KyEBJC2VMl+DchmjYl+4aR3SPLMPf4hK8wqkUcoSTFudit z48TIa1wzl+07nHbFZOXMmXrxbThgV7MgVqI1Lzn6My98PjVlPtxwi5da7iHzC3RlG /mKXiGH9DJjeiuHyVbCIhLaUNvL0MdXcCCmO3gD4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Yaliang Wang , Thomas Bogendoerfer , Sasha Levin Subject: [PATCH 5.17 0654/1126] MIPS: pgalloc: fix memory leak caused by pgd_free() Date: Tue, 5 Apr 2022 09:23:21 +0200 Message-Id: <20220405070426.826625832@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220405070407.513532867@linuxfoundation.org> References: <20220405070407.513532867@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Yaliang Wang [ Upstream commit 2bc5bab9a763d520937e4f3fe8df51c6a1eceb97 ] pgd page is freed by generic implementation pgd_free() since commit f9cb654cb550 ("asm-generic: pgalloc: provide generic pgd_free()"), however, there are scenarios that the system uses more than one page as the pgd table, in such cases the generic implementation pgd_free() won't be applicable anymore. For example, when PAGE_SIZE_4KB is enabled and MIPS_VA_BITS_48 is not enabled in a 64bit system, the macro "PGD_ORDER" will be set as "1", which will cause allocating two pages as the pgd table. Well, at the same time, the generic implementation pgd_free() just free one pgd page, which will result in the memory leak. The memory leak can be easily detected by executing shell command: "while true; do ls > /dev/null; grep MemFree /proc/meminfo; done" Fixes: f9cb654cb550 ("asm-generic: pgalloc: provide generic pgd_free()") Signed-off-by: Yaliang Wang Signed-off-by: Thomas Bogendoerfer Signed-off-by: Sasha Levin --- arch/mips/include/asm/pgalloc.h | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/mips/include/asm/pgalloc.h b/arch/mips/include/asm/pgalloc.h index c7925d0e9874..867e9c3db76e 100644 --- a/arch/mips/include/asm/pgalloc.h +++ b/arch/mips/include/asm/pgalloc.h @@ -15,6 +15,7 @@ #define __HAVE_ARCH_PMD_ALLOC_ONE #define __HAVE_ARCH_PUD_ALLOC_ONE +#define __HAVE_ARCH_PGD_FREE #include static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd, @@ -48,6 +49,11 @@ static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd) extern void pgd_init(unsigned long page); extern pgd_t *pgd_alloc(struct mm_struct *mm); +static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd) +{ + free_pages((unsigned long)pgd, PGD_ORDER); +} + #define __pte_free_tlb(tlb,pte,address) \ do { \ pgtable_pte_page_dtor(pte); \