From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx01.omp.ru (mx01.omp.ru [90.154.21.10]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8EB5072600; Wed, 2 Jul 2025 16:47:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.154.21.10 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751474873; cv=none; b=dSznHsPX27IU+iXDqkM3mhvxL1ndUpGhiE15wBWpuKhECXOcN/B9HkVp/hk8nUYtKalj9MXBwKiqGEWdfv1kmN7jegoiH3onRpgoQ2SqDS5HqSEDVnEjxCKbVQKGUn35t9/MLn2oHfLuiT2iPKO+K8Ybm8l9jovV1fpZvOH06kw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751474873; c=relaxed/simple; bh=kdtzP1DOdxUyE0j4okOCKRrjES3jFyJi9K58SvycYIg=; h=Message-ID:Date:MIME-Version:Subject:From:To:CC:References: In-Reply-To:Content-Type; b=n2hFvEb43UptHzyK4go1crmlToCyEOFnv17zJyyRm1pOxnfQ7ub9rjpPTTANWXwKcNLUPZkjvnQ6QLAV/p9joCxwvQmeoQcfxm+tb+8B29FoHIFJnheizRoV9GLMs+/qGCISPkFa98OQNeDLsTe6oqu2/UT2wXLGUhIZCt3j2iQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=omp.ru; spf=pass smtp.mailfrom=omp.ru; arc=none smtp.client-ip=90.154.21.10 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=omp.ru Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=omp.ru Received: from [192.168.2.102] (213.87.129.136) by msexch01.omp.ru (10.188.4.12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.2.1258.12; Wed, 2 Jul 2025 19:47:37 +0300 Message-ID: <8244b3f4-ea69-46ee-9ba2-6711f516f00b@omp.ru> Date: Wed, 2 Jul 2025 19:47:36 +0300 Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2] NFSv4: prevent integer overflow while calling nfs4_set_lease_period() From: Sergey Shtylyov To: , Trond Myklebust , Anna Schumaker CC: References: Content-Language: en-US Organization: Open Mobile Platform In-Reply-To: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: msexch01.omp.ru (10.188.4.12) To msexch01.omp.ru (10.188.4.12) X-KSE-ServerInfo: msexch01.omp.ru, 9 X-KSE-AntiSpam-Interceptor-Info: scan successful X-KSE-AntiSpam-Version: 6.1.1, Database issued on: 07/02/2025 16:33:19 X-KSE-AntiSpam-Status: KAS_STATUS_NOT_DETECTED X-KSE-AntiSpam-Method: none X-KSE-AntiSpam-Rate: 19 X-KSE-AntiSpam-Info: Lua profiles 194502 [Jul 02 2025] X-KSE-AntiSpam-Info: Version: 6.1.1.11 X-KSE-AntiSpam-Info: Envelope from: s.shtylyov@omp.ru X-KSE-AntiSpam-Info: LuaCore: 63 0.3.63 9cc2b4b18bf16653fda093d2c494e542ac094a39 X-KSE-AntiSpam-Info: {rep_avail} X-KSE-AntiSpam-Info: {Tracking_uf_ne_domains} X-KSE-AntiSpam-Info: {Tracking_from_domain_doesnt_match_to} X-KSE-AntiSpam-Info: {SMTP from is not routable} X-KSE-AntiSpam-Info: {Found in DNSBL: 213.87.129.136 in (user) b.barracudacentral.org} X-KSE-AntiSpam-Info: {Found in DNSBL: 213.87.129.136 in (user) dbl.spamhaus.org} X-KSE-AntiSpam-Info: d41d8cd98f00b204e9800998ecf8427e.com:7.1.1;127.0.0.199:7.1.2;omp.ru:7.1.1 X-KSE-AntiSpam-Info: {Tracking_ip_hunter} X-KSE-AntiSpam-Info: FromAlignment: s X-KSE-AntiSpam-Info: ApMailHostAddress: 213.87.129.136 X-KSE-AntiSpam-Info: {DNS response errors} X-KSE-AntiSpam-Info: Rate: 19 X-KSE-AntiSpam-Info: Status: not_detected X-KSE-AntiSpam-Info: Method: none X-KSE-AntiSpam-Info: Auth:dmarc=temperror header.from=omp.ru;spf=temperror smtp.mailfrom=omp.ru;dkim=none X-KSE-Antiphishing-Info: Clean X-KSE-Antiphishing-ScanningType: Heuristic X-KSE-Antiphishing-Method: None X-KSE-Antiphishing-Bases: 07/02/2025 16:36:00 X-KSE-Antivirus-Interceptor-Info: scan successful X-KSE-Antivirus-Info: Clean, bases: 7/2/2025 2:58:00 PM X-KSE-Attachment-Filter-Triggered-Rules: Clean X-KSE-Attachment-Filter-Triggered-Filters: Clean X-KSE-BulkMessagesFiltering-Scan-Result: InTheLimit On 7/1/25 11:35 PM, Sergey Shtylyov wrote: > The nfs_client::cl_lease_time field (as well as the jiffies variable it's > used with) is declared as *unsigned long*, which is 32-bit type on 32-bit > arches and 64-bit type on 64-bit arches. When nfs4_set_lease_period() that > sets nfs_client::cl_lease_time is called, 32-bit nfs_fsinfo::lease_time > field is multiplied by HZ -- that might overflow before being implicitly > cast to *unsigned long*. Actually, there's no need to multiply by HZ at all > the call sites of nfs4_set_lease_period() -- it makes more sense to do that > once, inside that function, calling check_mul_overflow() and capping result > at ULONG_MAX on actual overflow... > > Found by Linux Verification Center (linuxtesting.org) with the Svace static > analysis tool. > > Signed-off-by: Sergey Shtylyov > Cc: stable@vger.kernel.org > > --- > The patch is against the master branch of Trond Myklebust's linux-nfs.git repo. > > Changes in version 2: > - made use of check_mul_overflow() instead of mul_u32_u32(); > - capped the multiplication result at ULONG_MAX instead of returning -ERANGE, > keeping nfs4_set_lease_period() *void*; > - rewrote the patch description accordingly. Forgot to say that I had to adjust the patch description to make it clear that the overflow happens on 64-bit arches as well... [...] MBR, Sergey