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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1D95DE65D29 for ; Fri, 22 Nov 2024 06:19:48 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 5379E8D0008; Fri, 22 Nov 2024 01:19:47 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 4F01F8D0007; Fri, 22 Nov 2024 01:19:47 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3AEA38D0008; Fri, 22 Nov 2024 01:19:47 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 193B48D0007 for ; Fri, 22 Nov 2024 01:19:47 -0500 (EST) Received: from smtpin02.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id 84A581A1706 for ; Fri, 22 Nov 2024 06:19:46 +0000 (UTC) X-FDA: 82812729384.02.1BAFD38 Received: from nyc.source.kernel.org (nyc.source.kernel.org [147.75.193.91]) by imf17.hostedemail.com (Postfix) with ESMTP id AFCF940002 for ; Fri, 22 Nov 2024 06:19:03 +0000 (UTC) Authentication-Results: imf17.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b="fv/cDF8b"; dmarc=none; spf=pass (imf17.hostedemail.com: domain of akpm@linux-foundation.org designates 147.75.193.91 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1732256197; a=rsa-sha256; cv=none; b=8eoeuK4uqBBJeXW36ciZnT3AfO3VCD5242G411qYWaGBaypUY9uWVFKc4QwgewOrMwCNCm fU5653esjYVo/ZyulrhU2V2orIeoxuJZmN+1S4U2kNo9FgVBg+sf3i5KS/LkGXh2ayXzLK bFZD6Pd6z+M5NODNd/Vt4A3fF+8+e7M= ARC-Authentication-Results: i=1; imf17.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b="fv/cDF8b"; dmarc=none; spf=pass (imf17.hostedemail.com: domain of akpm@linux-foundation.org designates 147.75.193.91 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1732256197; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=f1uQd9pWiSi051nDtd6ibIX7ggiWCwmdWVUfKwO30f4=; b=nIxhfHVyXC/ZVE3ojOJAqQX9h6vaIzzMCC9Ew9L8vN5nK7ASjeLEGLB/VJpIKTcPKlyAF/ 8TCAbqVt+CkZHUM+MEoHoTC8Ptf5qKyB/b+0a4RCsIKwT/pjKSmBv98Uu/6b4zjmNQQGtS h8IihXd2SrUQjrDpaLK+/LUalfk3GHU= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by nyc.source.kernel.org (Postfix) with ESMTP id D9B2FA40C35; Fri, 22 Nov 2024 06:17:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 85949C4CECE; Fri, 22 Nov 2024 06:19:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1732256383; bh=TV1/1YnZIDQZeSYDM7Yx4q9AWg2k3f1mpbgpQnwfFhg=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=fv/cDF8b1qk4Ooq+bjOA6rpWocxQJ/+HNWvWlE7rSou39bShaui+b2ACVhxRlcUkd O9pB6osQs7vGTYZIN6x5evS+u+g3zqgylmrNcOnfuIhHxZJ5Er1ddv8ftVxwksVFwJ b738Ra0bFdv6RfByzPb1+AeEaFjRFnekNY4KbI7I= Date: Thu, 21 Nov 2024 22:19:37 -0800 From: Andrew Morton To: "Liam R. Howlett" Cc: David Hildenbrand , linux-kernel@vger.kernel.org, linux-mm@kvack.org, syzbot+3511625422f7aa637f0d@syzkaller.appspotmail.com, stable@vger.kernel.org, Christoph Lameter Subject: Re: [PATCH v1] mm/mempolicy: fix migrate_to_node() assuming there is at least one VMA in a MM Message-Id: <20241121221937.c41ee2b5e8534729e94fc104@linux-foundation.org> In-Reply-To: References: <20241120201151.9518-1-david@redhat.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Stat-Signature: 4zywp9nqy3yqp1n415qzn6ajn53ekn57 X-Rspamd-Queue-Id: AFCF940002 X-Rspamd-Server: rspam08 X-Rspam-User: X-HE-Tag: 1732256343-578518 X-HE-Meta: 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 Slit9aFN NU77SyP4FOUU1bLsnwO66rOYWk1St0GdJhrwFJxDpUYJifeqBUgv64HbLvBTchcSWmjpLPVqwWPIOInRXR4WspiP3J60pyW7qShaY1lVahUze7YcXSkOR1RsIjU7GBplw9XlpTD1DDYzVIbza6pfqywV9R6EZ7Lava9Zp6HNOPo8GUEZ2ZwPJjVgVJ6RjhQs68ZYccCUMH4FZHiDvPl2NYziYYRX05/2IKB4k61iACwFG8nhb/+9rGAAEnlxc9DNfUZP9niX9Xl678mVuBx/luYl2Fi6mR/BgV/F7uCkPmq1wyoOYeWpp0YpSadIqOBT5NBL9pAZGp3AV5CnubOw9HOAZmbcmw/FMptCqJWkmDa86DX+simWVbBi8W3mizZHUpAX48ybXYfTTI+MUX7D3nwJnxZ5w5I+G+4l+ugbsmZ151vsVZA9so+SE46PBZ2+e0g++ X-Bogosity: Ham, tests=bogofilter, spamicity=0.000016, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, 20 Nov 2024 15:27:46 -0500 "Liam R. Howlett" wrote: > I hate the extra check because syzbot can cause this as this should > basically never happen in real life, but it seems we have to add it. So.. --- a/mm/mempolicy.c~mm-mempolicy-fix-migrate_to_node-assuming-there-is-at-least-one-vma-in-a-mm-fix +++ a/mm/mempolicy.c @@ -1080,7 +1080,7 @@ static long migrate_to_node(struct mm_st mmap_read_lock(mm); vma = find_vma(mm, 0); - if (!vma) { + if (unlikely(!vma)) { mmap_read_unlock(mm); return 0; } _ ?