[Samba] VM_GROWSDOWN problem on S/390

[Andrew Bartlett]

John Nealy wrote:
> 
> We're running Samba 2.2.2 on an S/390 mainframe and have been experiencing
> problems with Samba seeming to access an invalid memory location. Below is
> part of the message log:
> 
> Feb 15 10:48:38 linux1 kernel: VM_GROWSDOWN not set, but address 0
> 
> Feb 15 10:48:38 linux1 kernel: not in vma 0106a960 (start 400000 end
> 53A000)
> Feb 15 10:48:38 linux1 kernel: User process fault: interruption code 0x10
> 
> Feb 15 10:48:38 linux1 kernel: failing address: 0
> 
> Feb 15 10:48:38 linux1 kernel: CPU:    0
> 
> Feb 15 10:48:38 linux1 kernel: Process smbd (pid: 3725,
> stackpage=00339000)
> Feb 15 10:48:38 linux1 kernel:
> 
> Feb 15 10:48:38 linux1 kernel: User PSW:    0709c000 8043a2d8
> 
> Feb 15 10:48:38 linux1 kernel: task: 00338000 tss: 003382d8 ksp: 00339cf8
> pt_reg
> s: 00339f68
> 
> Feb 15 10:48:38 linux1 kernel: User GPRS:
> 
> Feb 15 10:48:38 linux1 kernel: 00000000  00000000  00000000  00000000
> 
> Feb 15 10:48:38 linux1 kernel: 005cd940  005cd940  0000ffff  00000028
> 
> Feb 15 10:48:38 linux1 kernel: 00000028  7ffffa68  0000004c  005cc908
> 
> Feb 15 10:48:38 linux1 kernel: c013cc30  8043a02c  8043a1c0  7ffff4e0
> 
> Feb 15 10:48:38 linux1 kernel: User ACRS:
> 
> Feb 15 10:48:38 linux1 kernel: 00000000  00000000  00000000  00000000
> 
> Feb 15 10:48:38 linux1 kernel: 00000001  00000000  00000000  00000000
> 
> Feb 15 10:48:38 linux1 kernel: 00000000  00000000  00000000  00000000
> 
> Feb 15 10:48:38 linux1 kernel: 00000000  00000000  00000000  00000000
> 
> Feb 15 10:48:38 linux1 kernel: Kernel BackChain  CallChain    BackChain
> CallCha
> in
> 
> Feb 15 10:48:38 linux1 kernel:        00339cf8   0000004c
> 
> 
> After a few of these messages, the system eventually hangs - No network
> connection and no ability to enter commands directly from the management
> console.  Previous versions worked just fine for us.

Well, the first thing to note is that if Samba brings down the whole
server, then the server is broken.   But you probably have a bug in
Samba that triggers what looks to be a simple SegV, just s390 style.

> BTW, the 2.2.2 version of SWAT seems to behave differently. I had v2.2.1a
> setup so that user accessed the SWAT pages with only their Samba
> userid/passwd, and the could manage them that way.  Now, it seems to only
> grant access when you put in your Linux id/passwd, and it doesn't change
> the Samba password at all.

SWAT always uses the Linux password to grant access, but my allow
'password changes' for the samba password, given the old and new samba
password.

Andrew Bartlett

-- 
Andrew Bartlett                                 abartlet at pcug.org.au
Manager, Authentication Subsystems, Samba Team  abartlet at samba.org
Student Network Administrator, Hawker College   abartlet at hawkerc.net
http://samba.org     http://build.samba.org     http://hawkerc.net