onsdag den 22 september 2010 klockan 18:47 skrev Mats Erik Andersson detta: > Hello, > > the code in > > ifconfig/system/linux.c > > is broken on my Debian Squeeze amd64 machine. I am starting from > a fresh git checkout for x86 and x86_64, but the latter fails in > execution. > > The function linux_if_nameindex() is clearly broken on x86_64. > It is used as > > ### End of ifconfig/system/linux.c > > system_if_nameindex = linux_if_nameindex > > It is broken in the sense that every structure element "if_name" > is the empty string. The number of entries returned is correct,
I am not yet certain that I have found the fault, but I have certainly
found a case of buffer overrun in said function. It is easy to construct
unusual strings -- not expected in /proc/net/dev though -- that would brake
the code as it was until now.
Mats E A
=========================================================================
From 56dd929ce4ab78872d93159bc200e46f30b0acdf Mon Sep 17 00:00:00 2001
From: Mats Erik Andersson <g...@gisladisker.se>
Date: Thu, 23 Sep 2010 00:45:25 +0200
Subject: [PATCH] ifconfig/system/linux.c: Recalculate a search range.
---
ChangeLog | 5 +++++
ifconfig/system/linux.c | 2 +-
2 files changed, 6 insertions(+), 1 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index 1ff6282..cba4d58 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2010-09-23 Mats Erik Andersson <g...@gisladisker.se>
+
+ * ifconfig/system/linux.c (linux_if_nameindex): Express the exact
+ amount remaining of the string when locating next token.
+
2010-09-15 Mats Erik Andersson <g...@gisladisker.se>
* telnetd/telnetd.c (login_invocation, argp_options):
diff --git a/ifconfig/system/linux.c b/ifconfig/system/linux.c
index 0f4e579..808d252 100644
--- a/ifconfig/system/linux.c
+++ b/ifconfig/system/linux.c
@@ -886,7 +886,7 @@ linux_if_nameindex (void)
}
for (it = memchr (content, ':', length), index = 0; it;
- it = memchr (it, ':', it - content), index++)
+ it = memchr (it, ':', length - (it - content)), index++)
{
char *start = it - 1;
*it = '\0';
--
1.7.1
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