From patchwork Sun Nov 5 20:29:36 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sergey Shtylyov X-Patchwork-Id: 13446120 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (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 640F9BE6D for ; Sun, 5 Nov 2023 20:29:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=none Received: from mx01.omp.ru (mx01.omp.ru [90.154.21.10]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C9D6CB8 for ; Sun, 5 Nov 2023 12:29:52 -0800 (PST) Received: from localhost.localdomain (178.176.72.158) 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; Sun, 5 Nov 2023 23:29:42 +0300 From: Sergey Shtylyov To: Kees Cook , Tony Luck , "Guilherme G. Piccoli" , Subject: [PATCH] pstore: ram_core: fix possible overflow in persistent_ram_init_ecc() Date: Sun, 5 Nov 2023 23:29:36 +0300 Message-ID: <20231105202936.25694-1-s.shtylyov@omp.ru> X-Mailer: git-send-email 2.26.3 Precedence: bulk X-Mailing-List: linux-hardening@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Originating-IP: [178.176.72.158] 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: 6.0.0, Database issued on: 11/05/2023 20:08:36 X-KSE-AntiSpam-Status: KAS_STATUS_NOT_DETECTED X-KSE-AntiSpam-Method: none X-KSE-AntiSpam-Rate: 59 X-KSE-AntiSpam-Info: Lua profiles 181122 [Nov 03 2023] X-KSE-AntiSpam-Info: Version: 6.0.0.2 X-KSE-AntiSpam-Info: Envelope from: s.shtylyov@omp.ru X-KSE-AntiSpam-Info: LuaCore: 543 543 1e3516af5cdd92079dfeb0e292c8747a62cb1ee4 X-KSE-AntiSpam-Info: {rep_avail} X-KSE-AntiSpam-Info: {Tracking_from_domain_doesnt_match_to} X-KSE-AntiSpam-Info: {relay has no DNS name} X-KSE-AntiSpam-Info: {SMTP from is not routable} X-KSE-AntiSpam-Info: omp.ru:7.1.1;127.0.0.199:7.1.2;178.176.72.158:7.1.2;d41d8cd98f00b204e9800998ecf8427e.com:7.1.1 X-KSE-AntiSpam-Info: ApMailHostAddress: 178.176.72.158 X-KSE-AntiSpam-Info: {DNS response errors} X-KSE-AntiSpam-Info: Rate: 59 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: 11/05/2023 20:14:00 X-KSE-Antivirus-Interceptor-Info: scan successful X-KSE-Antivirus-Info: Clean, bases: 11/5/2023 6:43:00 PM X-KSE-Attachment-Filter-Triggered-Rules: Clean X-KSE-Attachment-Filter-Triggered-Filters: Clean X-KSE-BulkMessagesFiltering-Scan-Result: InTheLimit In persistent_ram_init_ecc(), on 64-bit arches DIV_ROUND_UP() will return 64-bit value since persistent_ram_zone::buffer_size has type size_t which is derived from the 64-bit *unsigned long*, while the ecc_blocks variable this value gets assigned to has (always 32-bit) *int* type. Even if that value fits into *int* type, an overflow is still possible when calculating the size_t typed ecc_total variable further below since there's no cast to any 64-bit type before multiplication. Declaring the ecc_blocks variable as *unsigned long* should fix this mess... Found by Linux Verification Center (linuxtesting.org) with the SVACE static analysis tool. Fixes: 9cc05ad97c57 ("staging: android: persistent_ram: refactor ecc support") Signed-off-by: Sergey Shtylyov --- The patch is against the 'master' branch of Linus Torvalds' repo. fs/pstore/ram_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c index 650e437b55e6..131c1923b8c0 100644 --- a/fs/pstore/ram_core.c +++ b/fs/pstore/ram_core.c @@ -190,7 +190,7 @@ static int persistent_ram_init_ecc(struct persistent_ram_zone *prz, { int numerr; struct persistent_ram_buffer *buffer = prz->buffer; - int ecc_blocks; + unsigned long ecc_blocks; size_t ecc_total; if (!ecc_info || !ecc_info->ecc_size)