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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5C775C3A5A4 for ; Fri, 30 Aug 2019 10:49:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 27F5621897 for ; Fri, 30 Aug 2019 10:49:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728007AbfH3KtS (ORCPT ); Fri, 30 Aug 2019 06:49:18 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:49749 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726902AbfH3KtS (ORCPT ); Fri, 30 Aug 2019 06:49:18 -0400 Received: from 1.general.cking.uk.vpn ([10.172.193.212] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1i3eSv-0008Tr-6K; Fri, 30 Aug 2019 10:49:13 +0000 From: Colin King To: David Howells , linux-afs@lists.infradead.org Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] afs: use BIT_ULL for shifting to fix integer overflow Date: Fri, 30 Aug 2019 11:49:12 +0100 Message-Id: <20190830104912.1090-1-colin.king@canonical.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Colin Ian King The expression 1 << nr_slots is evaluated with 32 bit integer arithmetic and can overflow before it is widened. Instead, use BIT_ULL to avoid overflow. Addresses-Coverity: ("Unintentional integer overflow") Fixes: 63a4681ff39c ("afs: Locally edit directory data for mkdir/create/unlink/...") Signed-off-by: Colin Ian King --- fs/afs/dir_edit.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/afs/dir_edit.c b/fs/afs/dir_edit.c index d4fbe5f85f1b..f360119923aa 100644 --- a/fs/afs/dir_edit.c +++ b/fs/afs/dir_edit.c @@ -36,7 +36,7 @@ static int afs_find_contig_bits(union afs_xdr_dir_block *block, unsigned int nr_ bitmap |= (u64)block->hdr.bitmap[7] << 7 * 8; bitmap >>= 1; /* The first entry is metadata */ bit = 1; - mask = (1 << nr_slots) - 1; + mask = BIT_ULL(nr_slots) - 1; do { if (sizeof(unsigned long) == 8) @@ -70,7 +70,7 @@ static void afs_set_contig_bits(union afs_xdr_dir_block *block, { u64 mask, before, after; - mask = (1 << nr_slots) - 1; + mask = BIT_ULL(nr_slots) - 1; mask <<= bit; before = *(u64 *)block->hdr.bitmap; @@ -95,7 +95,7 @@ static void afs_clear_contig_bits(union afs_xdr_dir_block *block, { u64 mask, before, after; - mask = (1 << nr_slots) - 1; + mask = BIT_ULL(nr_slots) - 1; mask <<= bit; before = *(u64 *)block->hdr.bitmap; -- 2.20.1