From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) (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 7CDD01C9DCB for ; Thu, 23 Jan 2025 06:20:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.51 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737613223; cv=none; b=rz9Vtw49DnjjO5CFx30p9tjQNdXKRfoucLoS0tuMpBKFfoHbeW6qoZAkbKykLKu+/3czA54TjzWMeJvXcQ8hWDZSqaofkx6x3W38mpTKy7OOdeBo+L6Y8BXCFbBAaJZO1QzEbihQ3GhKTHxCGvK5LcKkukbFSLVqdHF4ZhIV0kA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737613223; c=relaxed/simple; bh=YRCMSwxcYLnU3s0z+vl49tWnwmIzBuhasukTGFRNiZE=; h=Subject:To:Cc:References:From:Message-ID:Date:MIME-Version: In-Reply-To:Content-Type; b=IihCHdbmb0MrbugqhIfSdff+GP8bB7r5leToRyVNZeDcddIAe0+0wbeRkXTzFbg3JLPbWnZMi2OADNoukr3ZCnS9rS1RDkbdarAlyXJYNU5Mnp6ayE8r/EGShpVgCHeN0ME43eTfveRCzyO94FIhuk8kRzxvDgkyWr/Dvj65hb8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.93.142]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4YdrQQ5SvVz4f3jks for ; Thu, 23 Jan 2025 14:19:58 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id 3DCCD1A10CD for ; Thu, 23 Jan 2025 14:20:14 +0800 (CST) Received: from [10.174.178.129] (unknown [10.174.178.129]) by APP4 (Coremail) with SMTP id gCh0CgBXuV2M35Fn2Oz3Bg--.39538S2; Thu, 23 Jan 2025 14:20:13 +0800 (CST) Subject: Re: [PATCH] mm/compaction: fix UBSAN shift-out-of-bounds warning To: Liu Shixin , Andrew Morton , Kefeng Wang , Baolin Wang , Mel Gorman , David Hildenbrand , Matthew Wilcox , Nanyong Sun Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20250123021029.2826736-1-liushixin2@huawei.com> From: Kemeng Shi Message-ID: <71a9cabf-974e-08bf-45b6-e760425ec6cc@huaweicloud.com> Date: Thu, 23 Jan 2025 14:19:56 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.5.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: <20250123021029.2826736-1-liushixin2@huawei.com> Content-Type: text/plain; charset=gbk Content-Transfer-Encoding: 7bit X-CM-TRANSID:gCh0CgBXuV2M35Fn2Oz3Bg--.39538S2 X-Coremail-Antispam: 1UD129KBjvdXoWruF4fCr4fKr48uw13Kr4rXwb_yoWkuFXE9a 1qyF4fAanIqr92yFnrCF1fZF1UGa48Zw17ta4DGr42vas2qan2gF1DXryftryfJF9rWFnI kwn5ZFWkKwnI9jkaLaAFLSUrUUUUjb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUba8YFVCjjxCrM7AC8VAFwI0_Gr0_Xr1l1xkIjI8I6I8E6xAIw20E Y4v20xvaj40_Wr0E3s1l1IIY67AEw4v_Jr0_Jr4l8cAvFVAK0II2c7xJM28CjxkF64kEwV A0rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVW7JVWDJwA2z4x0Y4vE2Ix0cI8IcVCY1x02 67AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I 0E14v26rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40E x7xfMcIj6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x 0Yz7v_Jr0_Gr1lF7xvr2IY64vIr41lFIxGxcIEc7CjxVA2Y2ka0xkIwI1lc7I2V7IY0VAS 07AlzVAYIcxG8wCY1x0262kKe7AKxVWUtVW8ZwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4 IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1r MI8E67AF67kF1VAFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJV WUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Jr0_Gr1lIxAIcVCF04k26cxKx2IYs7xG6r1j 6r1xMIIF0xvEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Jr0_GrUvcS sGvfC2KfnxnUUI43ZEXa7IU17KsUUUUUU== X-CM-SenderInfo: 5vklyvpphqwq5kxd4v5lfo033gof0z/ on 1/23/2025 10:10 AM, Liu Shixin wrote: > syzkaller reported a UBSAN shift-out-of-bounds warning of (1UL << order) > in isolate_freepages_block(). The bogus compound_order can be any value > because it is union with flags. Add back the MAX_PAGE_ORDER check to fix > the warning. > > Fixes: 3da0272a4c7d ("mm/compaction: correctly return failure with bogus compound_order in strict mode") > Signed-off-by: Liu Shixin > --- > mm/compaction.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/mm/compaction.c b/mm/compaction.c > index a2b16b08cbbff..384e4672998e5 100644 > --- a/mm/compaction.c > +++ b/mm/compaction.c > @@ -630,7 +630,8 @@ static unsigned long isolate_freepages_block(struct compact_control *cc, > if (PageCompound(page)) { > const unsigned int order = compound_order(page); > > - if (blockpfn + (1UL << order) <= end_pfn) { > + if ((order <= MAX_PAGE_ORDER) && > + (blockpfn + (1UL << order) <= end_pfn)) { > blockpfn += (1UL << order) - 1; > page += (1UL << order) - 1; > nr_scanned += (1UL << order) - 1; > Look good to me, feel free to add Reviewed-by: Kemeng Shi