Bug 184357 - buffer_append_space: alloc not supported Error
Summary: buffer_append_space: alloc not supported Error
Alias: None
Product: Red Hat Enterprise Linux 4
Classification: Red Hat
Component: openssh
Version: 4.0
Hardware: All
OS: Linux
Target Milestone: ---
: ---
Assignee: Tomas Mraz
QA Contact: Brian Brock
Depends On:
TreeView+ depends on / blocked
Reported: 2006-03-08 07:13 UTC by Cove Schneider
Modified: 2007-11-30 22:07 UTC (History)
1 user (show)

Fixed In Version: RHSA-2007-0257
Doc Type: Bug Fix
Doc Text:
Clone Of:
Last Closed: 2007-05-01 17:29:29 UTC
Target Upstream Version:

Attachments (Terms of Use)
Patch against openssh-4.3p2 that appears to fix the problem (1.80 KB, patch)
2006-03-08 07:13 UTC, Cove Schneider
no flags Details | Diff
Kit to reproduce the problem (21.14 KB, application/octet-stream)
2006-03-08 07:17 UTC, Cove Schneider
no flags Details

System ID Private Priority Status Summary Last Updated
OpenSSH Project 1131 0 None None None Never
Red Hat Product Errata RHSA-2007:0257 0 normal SHIPPED_LIVE Low: openssh security and bug fix update 2007-05-01 17:28:49 UTC

Description Cove Schneider 2006-03-08 07:13:04 UTC
Description of problem:

Sshd fails if remote program generates too much output when using v2. It looks
like the code to throttle the stdout from the program being executed is
commented out in v2. So the sshd continues to allocate memory to buffer the
stdout until it hits aprox 10Mb and then it just aborts. This doesn't happen
with openssh's own client, possibly due to it's constant adjustments to the
window sizes works around it.

Version-Release number of selected component (if applicable):

All OpenSSH v2 versions at this point.

How reproducible:


Steps to Reproduce:
[see attachment]
1. Download cryptlib from http://www.cs.auckland.ac.nz/~pgut001/cryptlib/
2. Replace session/ssh2_msg.c and session/ssh2_rw.c with the ones included in
this tar file.
3. Compile cryptlib
4. Edit sshtest.c and put in your account settings and the path to the genstdout
5. Compile genstdout and sshtest (see compile.sh)
6. Run sshtest
Actual results:

In the sshd logs you'll find:
fatal: buffer_append_space: alloc 10489856 not supported

Expected results:

The program should just continue to run until interrupted.

Additional info:

Comment 1 Cove Schneider 2006-03-08 07:13:04 UTC
Created attachment 125784 [details]
Patch against openssh-4.3p2 that appears to fix the problem

Comment 2 Cove Schneider 2006-03-08 07:17:06 UTC
Created attachment 125785 [details]
Kit to reproduce the problem

Comment 4 Tomas Mraz 2006-04-04 15:08:12 UTC
It seems there is now a real patch in the upstream bugzilla.

Comment 5 Cove Schneider 2006-04-05 20:59:18 UTC
Latest patch works for me.


Comment 6 RHEL Program Management 2006-08-31 15:33:36 UTC
This request was evaluated by Red Hat Product Management for inclusion in a Red
Hat Enterprise Linux maintenance release.  Product Management has requested
further review of this request by Red Hat Engineering, for potential
inclusion in a Red Hat Enterprise Linux Update release for currently deployed
products.  This request is not yet committed for inclusion in an Update

Comment 8 Tomas Mraz 2006-10-05 08:52:21 UTC
Fixed in openssh-3.9p1-8.RHEL4.18

Comment 12 Red Hat Bugzilla 2007-05-01 17:29:29 UTC
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on the solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.


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