From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6B9426453 for ; Tue, 22 Mar 2022 21:44:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2EF77C340F2; Tue, 22 Mar 2022 21:44:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1647985456; bh=1o+/vlScURsqqtKv20aatWbXrGRQh7hTcKq2D/GnsUo=; h=Date:To:From:In-Reply-To:Subject:From; b=myQxlKVGAU2YOqcufqolY6980r6D+v6HSqx3qIPQmqNigZw3fM34RwCUyPFxyQh+M y/YsJ3g0n/e5i7qGdJxAQ9GzVrb5fTG9VyRcjJd3dOxEPWLNgRvZwx07x7oLMx4dvM 6jgkFV0kY338zGbVzORw1C8IIkWL8caL1kr5rIeo= Date: Tue, 22 Mar 2022 14:44:15 -0700 To: naoya.horiguchi@nec.com,linmiaohe@huawei.com,akpm@linux-foundation.org,patches@lists.linux.dev,linux-mm@kvack.org,mm-commits@vger.kernel.org,torvalds@linux-foundation.org,akpm@linux-foundation.org From: Andrew Morton In-Reply-To: <20220322143803.04a5e59a07e48284f196a2f9@linux-foundation.org> Subject: [patch 113/227] mm/memory-failure.c: catch unexpected -EFAULT from vma_address() Message-Id: <20220322214416.2EF77C340F2@smtp.kernel.org> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: From: Miaohe Lin Subject: mm/memory-failure.c: catch unexpected -EFAULT from vma_address() It's unexpected to walk the page table when vma_address() return -EFAULT. But dev_pagemap_mapping_shift() is called only when vma associated to the error page is found already in collect_procs_{file,anon}, so vma_address() should not return -EFAULT except with some bug, as Naoya pointed out. We can use VM_BUG_ON_VMA() to catch this bug here. Link: https://lkml.kernel.org/r/20220218090118.1105-3-linmiaohe@huawei.com Signed-off-by: Miaohe Lin Acked-by: Naoya Horiguchi Signed-off-by: Andrew Morton --- mm/memory-failure.c | 1 + 1 file changed, 1 insertion(+) --- a/mm/memory-failure.c~mm-memory-failurec-catch-unexpected-efault-from-vma_address +++ a/mm/memory-failure.c @@ -315,6 +315,7 @@ static unsigned long dev_pagemap_mapping pmd_t *pmd; pte_t *pte; + VM_BUG_ON_VMA(address == -EFAULT, vma); pgd = pgd_offset(vma->vm_mm, address); if (!pgd_present(*pgd)) return 0; _