[pptp-server] kernel panic with poptop 1.0.1 and 1.1.2 -- Only with broadband clients (?)

[Charlie Brady]

On Fri, 8 Mar 2002, Binesh Bannerjee wrote:

> /tmp/gunther/oops1:
> Mar  5 13:12:46 gunther kernel: Unable to handle kernel NULL pointer dereference at virtual address 00000070
> Mar  5 13:12:46 gunther kernel: current->tss.cr3 = 71198000, %cr3 = 71198000
> Mar  5 13:12:46 gunther kernel: *pde = 00000000
> Mar  5 13:12:46 gunther kernel: Oops: 0002
> Mar  5 13:12:46 gunther kernel: CPU:    0
> Mar  5 13:12:46 gunther kernel: EIP:    0010:[<fcd772bb>]
> Mar  5 13:12:46 gunther kernel: EFLAGS: 00010282
> Mar  5 13:12:46 gunther kernel: eax: f8482800   ebx: 00000077   ecx: 00000017   edx: 00000000
> Mar  5 13:12:46 gunther kernel: esi: f8482848   edi: f8482a85   ebp: ffff7723   esp: f1171e1c
> Mar  5 13:12:46 gunther kernel: ds: 0018   es: 0018   ss: 0018
> Mar  5 13:12:46 gunther kernel: Process pptpctrl (pid: 6300, process nr: 99, stackpage=f1171000)
> Mar  5 13:12:46 gunther kernel: Stack: ee199000 00000000 f8482800 000000fa f8482848 f8482848 00000000 f8699800
> Mar  5 13:12:46 gunther kernel:        f8482b2e 00000580 1b34c5cb 00000000 f8629980 fcd76fb3 f8482800 00000000
> Mar  5 13:12:46 gunther kernel:        f8482a34 000000fa f8482800 ee199000 00000000 0804dae0 00000292 f48a8f40
> Mar  5 13:12:46 gunther kernel: Call Trace: [<fcd76fb3>] [<fcd76b86>] [pty_unthrottle+44/96] [free_pages+39/44] [check_unthrottle+48/56] [read_chan+1659/2000] [tty_read+192/228]
> Mar  5 13:12:46 gunther kernel:        [sys_read+198/248] [system_call+52/64] [stext+43/169]
> Mar  5 13:12:46 gunther kernel: Code: f0 ff 4a 70 0f 94 c0 84 c0 74 0c 83 c4 f4 52 e8 6d ad 42 83

That is a kernel problem in the pty_unthrottle function. It just happens 
to be tickled by pptpctrl, but that doesn't mean that it is a problem with 
pptpctrl.

--
Charlie Brady                         charlieb at e-smith.com
Lead Product Developer
Network Server Solutions Group        http://www.e-smith.com/
Mitel Networks Corporation            http://www.mitel.com/
Phone: +1 (613) 368 4376 or 564 8000  Fax: +1 (613) 564 7739