From: Vegard Nossum <vegard.nossum@gmail.com>
Date: Fri, 25 Jul 2008 08:45:34 +0000 (-0700)
Subject: kallsyms: fix potential overflow in binary search
X-Git-Tag: v2.6.27-rc1~485
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2fc9c4e18f94431e7eb77d97edb2a995b46fba55;p=linux-2.6

kallsyms: fix potential overflow in binary search

This will probably never trigger... but it won't hurt to be careful.

http://googleresearch.blogspot.com/2006/06/extra-extra-read-all-about-it-nearly.html

Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
Cc: Joshua Bloch <jjb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index 6fc0040f3e..38fc10ac75 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -176,7 +176,7 @@ static unsigned long get_symbol_pos(unsigned long addr,
 	high = kallsyms_num_syms;
 
 	while (high - low > 1) {
-		mid = (low + high) / 2;
+		mid = low + (high - low) / 2;
 		if (kallsyms_addresses[mid] <= addr)
 			low = mid;
 		else