337520 – net-misc/selfdhcp _FORTIFY_SOURCE indicates presence of overflow

Bug 337520 - net-misc/selfdhcp _FORTIFY_SOURCE indicates presence of overflow

Summary: net-misc/selfdhcp _FORTIFY_SOURCE indicates presence of overflow

Status:	RESOLVED FIXED

Alias:	None

Product:	Gentoo Linux
Classification:	Unclassified
Component:	Current packages (show other bugs)
Hardware:	All Linux

Importance:	High major (vote)
Assignee:	No maintainer - Look at https://wiki.gentoo.org/wiki/Project:Proxy_Maintainers if you want to take care of it

URL:
Whiteboard:
Keywords:	Inclusion, PATCH

Depends on:
Blocks:	fortify-source
	Show dependency tree

Reported:	2010-09-15 17:23 UTC by Diego Elio Pettenò (RETIRED)
Modified:	2012-03-03 15:44 UTC (History)
CC List:	2 users (show)

See Also:
Package list:
Runtime testing required:	---

Attachments
Build log (selfdhcp-0.2a:20100915-154400.log,19.02 KB, text/plain) 2010-09-15 17:23 UTC, Diego Elio Pettenò (RETIRED)	Details
Patch to fix buffer overflow (selfdhcp-0.2a-buffer-overflow.patch,574 bytes, patch) 2011-01-29 14:08 UTC, Kevin McCarthy (RETIRED)	Details \| Diff
ebuild to apply the patch (selfdhcp-0.2a-r1.ebuild,812 bytes, text/plain) 2011-01-29 14:09 UTC, Kevin McCarthy (RETIRED)	Details
Fixed patch to provide enough space for the \0 (selfdhcp-0.2a-buffer-overflow.patch,576 bytes, patch) 2011-01-29 17:00 UTC, Kevin McCarthy (RETIRED)	Details \| Diff
Show Obsolete (1) View All Add an attachment (proposed patch, testcase, etc.)

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Description Diego Elio Pettenò (RETIRED) gentoo-dev

2010-09-15 17:23:11 UTC

You're receiving this bug because the package in Summary has produced _FORTIFY_SOURCE related warnings indicating the presence of a sure overflow in a static buffer.

Even though this is not always an indication of a security problem it might even be. So please check this out ASAP.

By the way, _FORTIFY_SOURCE is disabled when you disable optimisation, so don't try finding out the cause using -O0.

Thanks,
Your friendly neighborhood tinderboxer

Comment 1 Diego Elio Pettenò (RETIRED) gentoo-dev

2010-09-15 17:23:25 UTC

Created attachment 247488 [details]
Build log

Comment 2 Kevin McCarthy (RETIRED) gentoo-dev

2011-01-29 14:08:48 UTC

Created attachment 260990 [details, diff]
Patch to fix buffer overflow

Comment 3 Kevin McCarthy (RETIRED) gentoo-dev

2011-01-29 14:09:13 UTC

Created attachment 260991 [details]
ebuild to apply the patch

Comment 4 Diego Elio Pettenò (RETIRED) gentoo-dev

2011-01-29 16:52:00 UTC

Hi Kevin, your patch here has still a problem: strncpy() doesn't ensure a final '\0' with the size provided, so it should be sizeof(dest)-1 rather than simply sizeof(dest). It takes away the warning because it won't hit the limit but it won't take care of terminating it properly, so further errors could creep afterwards. The interface you were expecting is strlcpy() which is not available in GLIBC.

Comment 5 Kevin McCarthy (RETIRED) gentoo-dev

2011-01-29 17:00:28 UTC

Created attachment 261017 [details, diff]
Fixed patch to provide enough space for the \0

Nice catch... I should've known better, but it's been a while since I've done any heavy C development. Anyway, I've uploaded a corrected patch.

Comment 6 Pacho Ramos gentoo-dev

2012-03-03 15:44:43 UTC

+*selfdhcp-0.2a-r1 (03 Mar 2012)
+
+  03 Mar 2012; Pacho Ramos <pacho@gentoo.org>
+  +files/selfdhcp-0.2a-buffer-overflow.patch, +selfdhcp-0.2a-r1.ebuild,
+  -selfdhcp-0.2a.ebuild:
+  Fix overflow, bug #337520 by flameeyes and fix by Kevin McCarthy.
+