linux-kernel - [PATCH] memblock: fix memblock_next_valid

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>] [day] [month] [year] [list]

Date:   Fri,  3 Mar 2017 11:37:45 +0900
From:   AKASHI Takahiro <takahiro.akashi@...aro.org>
To:     akpm@...ux-foundation.org
Cc:     paul.burton@...tec.com, linux-kernel@...r.kernel.org,
        linux-mm@...ck.org, AKASHI Takahiro <takahiro.akashi@...aro.org>
Subject: [PATCH] memblock: fix memblock_next_valid_pfn()

Obviously, we should not access memblock.memory.regions[right]
if 'right' is outside of [0..memblock.memory.cnt>.

Fixes: b92df1de5d28 ("mm: page_alloc: skip over regions of invalid pfns where possible")
Signed-off-by: AKASHI Takahiro <takahiro.akashi@...aro.org>
---
 mm/memblock.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/mm/memblock.c b/mm/memblock.c
index b64b47803e52..696f06d17c4e 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -1118,7 +1118,10 @@ unsigned long __init_memblock memblock_next_valid_pfn(unsigned long pfn,
 		}
 	} while (left < right);
 
-	return min(PHYS_PFN(type->regions[right].base), max_pfn);
+	if (right == type->cnt)
+		return max_pfn;
+	else
+		return min(PHYS_PFN(type->regions[right].base), max_pfn);
 }
 
 /**
-- 
2.11.1