Multiple Platform remote CPU load issue in Samba 1.x and2.x
Allen, Michael B (RSCH)
Michael_B_Allen at ml.com
Wed Jun 14 00:47:05 GMT 2000
Actually could this be a kernel networking issue with linux? I'm running
2.2.14-5.0. If not it should be trivial to fix. Anyone with a current CVS
checkout wanna come up with a quick patch?
Kudos to "The SecureXpert Team" for bringing this to our attention!
Michael B. Allen
> -----Original Message-----
> From: J. Robert von Behren [SMTP:jrvb at cs.berkeley.edu]
> Sent: Tuesday, June 13, 2000 8:38 PM
> To: Michael_B_Allen at ml.com
> Cc: Multiple recipients of list SAMBA-TECHNICAL
> Subject: Re: Multiple Platform remote CPU load issue in Samba 1.x
> FWIW, I can reproduce this on my test machine (Redhat 6.0, kernel
> 2.2.5-15). The following command does the trick:
> nc localhost 139 < /dev/zero
> After watching smbd with gdb and strace, I found that the child smbd
> that was spawned in response to the nc connection just keeps reading
> zeros from the socket, and writing out error responses, ad infinitum. A
> simple fix would be to abort the connection after a certain number of
> successive bad requests, or after a certain number of bad requests
> within a given time period.
> Best regards,
> -Rob von Behren
> "Allen, Michael B (RSCH)" wrote:
> > > -----Original Message-----
> > > From: Allen, Michael B (RSCH)
> > >
> > >
> > > but smbd seems to drop the conn.
> > [Allen, Michael B (RSCH)]
> > Actually , I'm sorry this is not true. It appears to maintain
> > connection and then close when the netcat program stops but there only a
> > packets transpire on connection and then again on disconnect.
> > PS:
> > [root at prodlinux lib]# cat /dev/zero > /dev/null
> > This runs the cpu up to 100% so I'm getting zeros
> > [root at prodlinux lib]# cat /dev/zero | ./netcat localhost 139
> > and this too does nothing.
> > Michael B. Allen
> > http://jcifs.samba.org
More information about the samba-technical