From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pg1-f177.google.com (mail-pg1-f177.google.com [209.85.215.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8EEF823ED60 for ; Thu, 20 Aug 2026 04:07:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.177 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787198869; cv=none; b=Z7JJKmEL0dpgpbgfaUHYCEROyFrmmkFJF7BC8hkfRCKOY5yKj7An2fezDjvqE7uQ/2ZiVBcVusXXZiZXxlsN8C1jr0uQCiSFln5UPTLoDUkbmrbOiK37iBiFSYN+0TSVwRnpjgzLm6g4xqr3zSWtdEGN+uvNqvzWtine79xKHaY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787198869; c=relaxed/simple; bh=+3Gdvw03t+o6K/FRZ+CvuEvcpqw0SjV0vPsIR0N8R7I=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=VqYWGV3fj3FPF0TDWVgYe1nTQOzlsn2z4UqfQiI0/NJ04DeJ8zd1JLPdGzBPBgxI1f9YpBJ6ojVardqC1zZ/j0hUd4e6a6XtVGfCqIXnWjReDGbh97ZUM11gsQAeo+IOdicHPHe17t+9nkUKG7tvPEagZZbIma3jaF+zBjZJY0o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=chromium.org; spf=pass smtp.mailfrom=chromium.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b=Zl1Uor3J; arc=none smtp.client-ip=209.85.215.177 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=chromium.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=chromium.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="Zl1Uor3J" Received: by mail-pg1-f177.google.com with SMTP id 41be03b00d2f7-c9aea40d799so885215a12.0 for ; Wed, 19 Aug 2026 21:07:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1787198867; x=1787803667; darn=vger.kernel.org; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:from:to:cc:subject :date:message-id:reply-to:content-type; bh=PsRws+ttrkbm7MW0VuqekGz+LjrPQ0W2mrmFSjJ7szA=; b=Zl1Uor3JU8YQRoIGUKfN0h6WW92o8uMJAEx8HJr9CzTPmtXNzSu7PuNVoaxw219iH7 ZlTF+vl2Nh92yG7YKUbW2I39alwymPmgEra7JJk2YaWys6rC8xirLQ09MEv0TZY9Sq/K jweb5iu+JCj+qYZlTdokj4wSIoEiAVRN4Hdd4= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1787198867; x=1787803667; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=PsRws+ttrkbm7MW0VuqekGz+LjrPQ0W2mrmFSjJ7szA=; b=tSmIps67vN7KruXW0mpmOHYtSetRAgMZRMxV2ynL5iGTMIqU+guJd4a5E7EDkz+AvV 4Xll34zvL3bFhLTiIE/10Ua2o94fIxirwR+NR278yZVzkaSSdz+O7mjGYi7c4jxfA2+/ 47Virpk80MZOGpQ82X2tjf4lJweWqpbnI35I99uKFNPCjwteu+ySt0ZaRCFixU2pkHDh 86ca/6SuIsEN1nTSQX4rxreZ9tnKugwgBU1O9w4nMSZEgRy8F5HSF8uM11XwAl7GyO74 39uQz4JuzFvtE8VvH8LmvLVROOTHHBSyBvQZcTUlVeI4N+tnWj+YrUO/in8Xck+/Dfz2 FPWQ== X-Forwarded-Encrypted: i=1; AHgh+Rr5G2dzOVodb1cLu4i+P/xzfQN/bM00R3+h0+0zclcmHjDCekfyNU/zjIuS5xANFTs79ekoV7KWk+2BniA=@vger.kernel.org X-Gm-Message-State: AFuF++kpb3O91bY/LYLciN3RA6uCARczoYGV9a4dNw6O8bPRFUq4YuvJ GO8nG8xs0xbqoxPwLohGZo4NGuC2IVODbivNeLjhB92AFEvU+r23ytNnfs8Zsq1RmQ== X-Gm-Gg: AR+sD10Dz0rimLe9q6sF3QCwnDmGtlIwnD3J1MDRmU2RoFfekDVBE3GnENZbJj5M47c glQLizLEaiAZ6kbyw97m6MAuVsb42uNQUQxtI0yPMzcu2itl7YxoWGqmtvQkRQbLp3FERr0ON0+ tQsiS+Lk2JIK1HFOeeEbWLLJzX4rOJIJ8CdwhKhNhG2pXI6MfSC4kA56TAze3bXlPFZG9jRrY9/ UGCuSrXKemqCPj548D/aUTjOmiT6LVic2x3eFtCUQ0fVNtbyK3L4OpCCmjtBLcw5i17vAGvgzDc MzbqbQj7ccXxipPCpCh436gm1XWF4jLkPycPvyvB6Vd3kPd1OgriKJKX1rRoZ4RWDvurBotRubJ +YHWYBP4/sGl68LenL4V8xjwqK4EVEMiS285IfPtyC7SvRme6AMJ0KKF5MHogxwEOL2soRtBDee 79I7s7kfGS1ADe/KaPI13uiuV6OXt/x+6Q5Z9hYDdPjrx1y3NQPJZYjgnVTm+aJALSzSdxZmDoy JWqK+w72+/1kKwbQTQNrfPo6/O9IfsmOQ== X-Received: by 2002:a17:90b:6c6:b0:37f:b0a9:1a68 with SMTP id 98e67ed59e1d1-395812a8bd9mr18713929a91.7.1787198866750; Wed, 19 Aug 2026 21:07:46 -0700 (PDT) Received: from google.com ([2a00:79e0:2031:6:7beb:7701:c87e:f611]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-3957fbbc017sm5518570a91.15.2026.08.19.21.07.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 19 Aug 2026 21:07:46 -0700 (PDT) Date: Thu, 20 Aug 2026 13:07:38 +0900 From: Sergey Senozhatsky To: Jiacheng Xu Cc: Minchan Kim , Sergey Senozhatsky , Jens Axboe , linux-kernel@vger.kernel.org Subject: Re: [PATCH] zram: reject disksize values that overflow PAGE_ALIGN Message-ID: References: <1760e5f1.15b52.1a01d28f800.Coremail.stitch@zju.edu.cn> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1760e5f1.15b52.1a01d28f800.Coremail.stitch@zju.edu.cn> On (26/08/20 11:13), Jiacheng Xu wrote: > disksize_store() parses the value written to the disksize sysfs > attribute with memparse() and then aligns it with PAGE_ALIGN(). > > For values in the last PAGE_SIZE - 1 bytes of the u64 range, the > addition performed by PAGE_ALIGN() wraps around. For example, > U64_MAX - 3 is aligned to zero. zram_meta_alloc() then calls > vzalloc(0), which triggers a warning in __vmalloc_node_range(). > > With panic_on_warn enabled, this can also result in a kernel panic. > > Reject values that cannot be safely page-aligned before calling > PAGE_ALIGN(). > > Fixes: cd67e10ac699 ("zram: promote zram from staging") > Signed-off-by: Jiacheng Xu > --- > drivers/block/zram/zram_drv.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c > index ace65c586072..2696bd3b29f6 100644 > --- a/drivers/block/zram/zram_drv.c > +++ b/drivers/block/zram/zram_drv.c > @@ -2876,6 +2876,9 @@ static ssize_t disksize_store(struct device *dev, struct > device_attribute *attr, > return -EBUSY; > } > > + if (disksize > U64_MAX - (PAGE_SIZE - 1)) > + return -EINVAL; > + > disksize = PAGE_ALIGN(disksize); > if (!zram_meta_alloc(zram, disksize)) > return -ENOMEM; I think we already check disksize boundaries (you probably want to check out linux-next): if (!num_pages || ((u64)num_pages << PAGE_SHIFT) != disksize) return -EINVAL;