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Re: FW: scp upload failure memory leak

From: Jeff Weber <jweber_at_amsc.com>
Date: Wed, 21 May 2008 21:08:37 -0500

On Wed, May 21, 2008 at 08:16:21PM +0200, Daniel Stenberg wrote:
> On Wed, 21 May 2008, Jeff Weber wrote:
>
>> I tried adding a call to
>> state(conn, SSH_SCP_CHANNEL_FREE);
>> inside ssh.c:scp_disconnect() to no avail. I'm not familiar with the
>> details
>> of the SSH state machine. Any help would be appreciated.
>>
>> Alternatively, I tried uploading to sftp:// . This protocol also leaks
>> upon a transfer timeout.
>
> I'll look into this as soon as I get some time for it. Any chance you can
> write up a test case for the test suite that repeats this problem? It'd
> help us a lot...

I've attached tests/data/test62[78] with scp and sftp upload timeouts
respectively, showing memory leaks. The tests requires an sshd that will write
to /dev/null. The test cases just upload /dev/zero to scp://localhost/dev/null
with a --max-time timeout.

I've studied the scp case a bit more, and can offer this: the timeout occurs
while a channel is open. The bug is that the SSH_CHANNEL_FREE state is not
entered before the SSH_SESSION_DISCONNECT state. Thus, the channel is leaked.

I have not had a chance to study the sftp timeout.

    Jeff

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Received on 2008-05-22