From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933360AbaJVMoF (ORCPT ); Wed, 22 Oct 2014 08:44:05 -0400 Received: from cantor2.suse.de ([195.135.220.15]:38780 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933049AbaJVMoD (ORCPT ); Wed, 22 Oct 2014 08:44:03 -0400 From: Jan Kara To: Andrew Morton Cc: linux-kernel@vger.kernel.org, Jan Kara , Rasmus Villemoes , stable@vger.kernel.org Subject: [PATCH] bitmap: Fix undefined shift in __bitmap_shift_left() Date: Wed, 22 Oct 2014 14:43:51 +0200 Message-Id: <1413981831-6902-1-git-send-email-jack@suse.cz> X-Mailer: git-send-email 1.8.1.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It __bitmap_shift_left() is asked to shift by a multiple of BITS_PER_LONG, it will try to shift a long value by BITS_PER_LONG bits which is undefined. Change the function to take this into account. Coverity-id: 1192175 CC: Rasmus Villemoes CC: stable@vger.kernel.org Signed-off-by: Jan Kara --- lib/bitmap.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/lib/bitmap.c b/lib/bitmap.c index cd250a2e14cb..02a8a439fcc7 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -172,7 +172,9 @@ void __bitmap_shift_left(unsigned long *dst, upper = src[k]; if (left && k == lim - 1) upper &= (1UL << left) - 1; - dst[k + off] = lower >> (BITS_PER_LONG - rem) | upper << rem; + dst[k + off] = upper << rem; + if (rem) + dst[k + off] |= lower >> (BITS_PER_LONG - rem); if (left && k + off == lim - 1) dst[k + off] &= (1UL << left) - 1; } -- 1.8.1.4