SIGSEGV in cyrus-imapd 3.0.7 mupdate

[ellie timoney]

Hi, 

Are you confident that the backtrace in your earlier email is from the thread that crashed?

mupdate is multithreaded, so obtaining the correct backtrace from a crash is a bit of work (but maybe you already did this)

It's been a while since I've done any multithreaded debugging with gcc (since Cyrus is predominantly single-threaded), but my fingers remember using "thread apply all bt" and going from there, if that's any help :)

Cheers,

ellie

On Thu, Jul 5, 2018, at 7:40 PM, Michael Menge wrote:
> Quoting Michael Menge <michael.menge at zdv.uni-tuebingen.de>:
> 
> > Hi,
> >
> > we are in the process of setting up our new production mailserver with
> > cyrus-imapd 3.0.7 on RHEL 7.5 Servers.
> >
> > At the moment we encounter many crashes (SIGSEGV) of the mupdate process on
> > the mupdate master instance. As soon as we issue a command that updates
> > multiple mailboxes in short time we trigger a SIGSEGV.
> >
> >> sam user/zrstes* cyrus all
> > Setting ACL on user/zrstes1...OK.
> > Setting ACL on user/zrstes1/Mail...OK.
> > Setting ACL on user/zrstes1/Mail/drafts...OK.
> > Setting ACL on user/zrstes1/Mail/s-spam...OK.
> > Setting ACL on user/zrstes1/Mail/sent...OK.
> > Setting ACL on user/zrstes1/Mail/trash...OK.
> > Setting ACL on user/zrstes1/Mail/v-spam...OK.
> > Setting ACL on user/zrstes2...cyrus: lrswipkxtea: no connection to server
> >
> > I suspect that at this time the connection from the backend to the  
> > mupdate master
> > is lost as the mupdate process received the SIGSEGV
> >
> > (gdb) bt
> > #0  0x00007fb49c000098 in ?? ()
> > #1  0x00007fb4a9a59a85 in DH_free (r=0x7fb49c1b9600) at dh_lib.c:194
> > #2  0x00007fb4aa84dbef in tls_shutdown_serverengine () at imap/tls.c:1311
> > #3  0x0000000000404075 in conn_free (C=0x7fb4840009f0) at imap/mupdate.c:379
> > #4  0x00000000004062c0 in thread_main (rock=0x0) at imap/mupdate.c:1330
> > #5  0x00007fb4a771add5 in start_thread (arg=0x7fb4a22d9700) at  
> > pthread_create.c:308
> > #6  0x00007fb4a718fb3d in clone () at  
> > ../sysdeps/unix/sysv/linux/x86_64/clone.S:113
> >
> >
> > Further information, as DH_free is in the bt, we have NOT configured  
> > dh_params in
> > our ssl certificate/key or in the imapd.conf
> >
> 
> As a follow up, we did generate dh_params, but the mupdate still crashes
> with SIGSEGV. Any ideas how to debug/fix this? Is there any  
> information that is missing?
> 
> Regards
> 
>     Michael Menge
> 
> 
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> Universität Tübingen                   Fax.: (49) 7071/29-5912
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