Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934599AbbHJKXZ (ORCPT ); Mon, 10 Aug 2015 06:23:25 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:44272 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934336AbbHJKSV (ORCPT ); Mon, 10 Aug 2015 06:18:21 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Rasmus Villemoes" , "Chris Metcalf" , "Linus Torvalds" Date: Mon, 10 Aug 2015 12:12:31 +0200 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 052/110] __bitmap_parselist: fix bug in empty string handling In-Reply-To: X-SA-Exim-Connect-IP: 2.173.94.72 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2450 Lines: 86 3.2.71-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Chris Metcalf commit 2528a8b8f457d7432552d0e2b6f0f4046bb702f4 upstream. bitmap_parselist("", &mask, nmaskbits) will erroneously set bit zero in the mask. The same bug is visible in cpumask_parselist() since it is layered on top of the bitmask code, e.g. if you boot with "isolcpus=", you will actually end up with cpu zero isolated. The bug was introduced in commit 4b060420a596 ("bitmap, irq: add smp_affinity_list interface to /proc/irq") when bitmap_parselist() was generalized to support userspace as well as kernelspace. Fixes: 4b060420a596 ("bitmap, irq: add smp_affinity_list interface to /proc/irq") Signed-off-by: Chris Metcalf Cc: Rasmus Villemoes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Ben Hutchings --- lib/bitmap.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -601,12 +601,12 @@ static int __bitmap_parselist(const char unsigned a, b; int c, old_c, totaldigits; const char __user __force *ubuf = (const char __user __force *)buf; - int exp_digit, in_range; + int at_start, in_range; totaldigits = c = 0; bitmap_zero(maskp, nmaskbits); do { - exp_digit = 1; + at_start = 1; in_range = 0; a = b = 0; @@ -635,11 +635,10 @@ static int __bitmap_parselist(const char break; if (c == '-') { - if (exp_digit || in_range) + if (at_start || in_range) return -EINVAL; b = 0; in_range = 1; - exp_digit = 1; continue; } @@ -649,16 +648,18 @@ static int __bitmap_parselist(const char b = b * 10 + (c - '0'); if (!in_range) a = b; - exp_digit = 0; + at_start = 0; totaldigits++; } if (!(a <= b)) return -EINVAL; if (b >= nmaskbits) return -ERANGE; - while (a <= b) { - set_bit(a, maskp); - a++; + if (!at_start) { + while (a <= b) { + set_bit(a, maskp); + a++; + } } } while (buflen && c == ','); return 0; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/