linux-kernel - [PATCH 1/2] memblock: add assertion for zero allocation size

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <1361471962-25164-2-git-send-email-vgupta@synopsys.com>
Date:	Fri, 22 Feb 2013 00:09:21 +0530
From:	Vineet Gupta <Vineet.Gupta1@...opsys.com>
To:	Andrew Morton <akpm@...ux-foundation.org>,
	Chris Zankel <chris@...kel.net>,
	Max Filippov <jcmvbkbc@...il.com>,
	Marc Gauthier <marc@...silica.com>
CC:	Vineet Gupta <Vineet.Gupta1@...opsys.com>,
	Tejun Heo <tj@...nel.org>, Yinghai Lu <yinghai@...nel.org>,
	Wanpeng Li <liwanp@...ux.vnet.ibm.com>,
	Ingo Molnar <mingo@...nel.org>, <linux-mm@...ck.org>,
	<linux-kernel@...r.kernel.org>
Subject: [PATCH 1/2] memblock: add assertion for zero allocation size

This came to light when calling memblock allocator from arc port (for
copying flattended DT). If a "0" alignment is passed, the allocator
round_up() call incorrectly rounds up the size to 0.

round_up(num, alignto) => ((num - 1) | (alignto -1)) + 1

While the obvious allocation failure causes kernel to panic, it is
better to BUG_ON() if effective size for allocation (as passed by caller
and/or computed after alignemtn rounding) is zero.

Signed-off-by: Vineet Gupta <vgupta@...opsys.com>
Cc: Andrew Morton <akpm@...ux-foundation.org>
Cc: Tejun Heo <tj@...nel.org>
Cc: Yinghai Lu <yinghai@...nel.org>
Cc: Wanpeng Li <liwanp@...ux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@...nel.org>
Cc: linux-mm@...ck.org
Cc: linux-kernel@...r.kernel.org
---
 mm/memblock.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/mm/memblock.c b/mm/memblock.c
index 1bcd9b9..32b36d0 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -824,6 +824,8 @@ static phys_addr_t __init memblock_alloc_base_nid(phys_addr_t size,
 	/* align @size to avoid excessive fragmentation on reserved array */
 	size = round_up(size, align);
 
+	BUG_ON(!size);
+
 	found = memblock_find_in_range_node(0, max_addr, size, align, nid);
 	if (found && !memblock_reserve(found, size))
 		return found;
-- 
1.7.4.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/