From: nobu@...
Date: 2014-08-04T11:46:52+00:00
Subject: [ruby-core:64186] [ruby-trunk - Bug #10019] segmentation fault/buffer overrun in pack.c (encodes)

Issue #10019 has been updated by Nobuyoshi Nakada.


Tomas Hoger wrote:
> * The first byte of the SSP cookie is expected to be '\0' on e.g. recent Linux systems (https://sourceware.org/bugzilla/show_bug.cgi?id=10149).  Hence off-by-one overflow with '\0' would not be detected.

`encodes()` does uuencode and mime-encode, so never writes '\0'.

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Bug #10019: segmentation fault/buffer overrun in pack.c (encodes)
https://bugs.ruby-lang.org/issues/10019#change-48189

* Author: Will Wood
* Status: Feedback
* Priority: Normal
* Assignee: 
* Category: core
* Target version: 
* ruby -v: ruby 2.1.2p168 (2014-07-06 revision 46721) [i386-mingw32]
* Backport: 2.0.0: REQUIRED, 2.1: DONE
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While working with an AWS sample I hit a segmentation fault.  The same sample works under 1.9.3.  It appeared to be coming from pack.c function encodes.  After looking at the source there's a 4K buffer allocated on the stack.  I made a minor change to base the buffer length off of the incoming buffer length with a pad and allocate it off the heap.  Anyway, after fixing this my code sample runs fine.  I'm including a patch file and the sample code.

---Files--------------------------------
pack.patch (2.74 KB)
BucketTest.rb (326 Bytes)
pack.c.patch (769 Bytes)


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