openssh unix dev - Jan 2001 - Problem with OpenSSH 2.3.0p1 and Linux kernel 2.4.1pre8 (Disconnecting: fork failed: Resource temporarily unavailable)

I'm having a problem with OpenSSH 2.3.0p1 and Linux kernel 2.4.1pre8. 
After a client connects and is authenticated ssh fails to fork, 
disconnects and dies. Normally I run sshd out of inetd with the -i flag. 
thinking this might be the problem I ran it in daemon mode from the 
command line. The results were the same. Running with maximum debugging 
on I captured the following:
<snip>
debug1: Local version string SSH-1.99-OpenSSH_2.3.0p1
debug1: Sent 1152 bit public key and 1024 bit host key.
debug1: Encryption type: 3des
debug1: Received session key; encryption turned on.
debug1: Installing crc compensation attack detector.
debug1: Starting up PAM with username "adminjf"
debug1: Attempting authentication for adminjf.
debug1: PAM Password authentication accepted for user "adminjf"
Accepted password for adminjf from 209.155.224.94 port 868
debug1: PAM setting rhost to "orion.inventivecomm.com"
debug1: session_new: init
debug1: session_new: session 0
debug1: Allocating pty.
debug1: PAM setting tty to "/dev/pts/0"
debug1: PAM establishing creds
Disconnecting: fork failed: Resource temporarily unavailable
debug1: Calling cleanup 0x8057aa0(0x80e47a0)
debug1: pty_cleanup_proc: /dev/pts/0
debug1: Calling cleanup 0x8050498(0x0)
debug1: Calling cleanup 0x80653c8(0x0)

Under 2.2.19pre7 everything works fine. Has anyone run across 2.4 kernel 
problems with OpenSSH?

Jayme Frye
System Administrator
Inventive Comm.
jfrye at inventivecomm.com

On Mon, 29 Jan 2001, Jayme Frye wrote:
> I'm having a problem with OpenSSH 2.3.0p1 and Linux kernel 2.4.1pre8. 
> After a client connects and is authenticated ssh fails to fork, 
> disconnects and dies. Normally I run sshd out of inetd with the -i flag. 
> thinking this might be the problem I ran it in daemon mode from the 
> command line. The results were the same. Running with maximum debugging 
> on I captured the following:
> <snip>
> debug1: Local version string SSH-1.99-OpenSSH_2.3.0p1
> debug1: Sent 1152 bit public key and 1024 bit host key.
> debug1: Encryption type: 3des
> debug1: Received session key; encryption turned on.
> debug1: Installing crc compensation attack detector.
> debug1: Starting up PAM with username "adminjf"
> debug1: Attempting authentication for adminjf.
> debug1: PAM Password authentication accepted for user "adminjf"
> Accepted password for adminjf from 209.155.224.94 port 868
> debug1: PAM setting rhost to "orion.inventivecomm.com"
> debug1: session_new: init
> debug1: session_new: session 0
> debug1: Allocating pty.
> debug1: PAM setting tty to "/dev/pts/0"
> debug1: PAM establishing creds
> Disconnecting: fork failed: Resource temporarily unavailable
> debug1: Calling cleanup 0x8057aa0(0x80e47a0)
> debug1: pty_cleanup_proc: /dev/pts/0
> debug1: Calling cleanup 0x8050498(0x0)
> debug1: Calling cleanup 0x80653c8(0x0)
> 
> Under 2.2.19pre7 everything works fine. Has anyone run across 2.4 kernel 
> problems with OpenSSH?
Looks like a kernel problem to me - if fork is failing, then lots of
other things may break. 

You do have an appropriate libc for your kernel?

-d

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