Re: Re: kern/58422: kernel crash when using the iscsi initiator

[6bone%6bone.informatik.uni-leipzig.de@localhost]

The following reply was made to PR kern/58422; it has been noted by GNATS.

From: 6bone%6bone.informatik.uni-leipzig.de@localhost
To: gnats-bugs%netbsd.org@localhost
Cc: kern-bug-people%netbsd.org@localhost, gnats-admin%netbsd.org@localhost, netbsd-bugs%netbsd.org@localhost
Subject: Re: Re: kern/58422: kernel crash when using the iscsi initiator
Date: Sun, 14 Jul 2024 20:58:05 +0200 (CEST)

 On Sat, 13 Jul 2024, Michael van Elst wrote:
 
 > Date: Sat, 13 Jul 2024 08:00:03 +0000 (UTC)
 > From: Michael van Elst <mlelstv%serpens.de@localhost>
 > Reply-To: gnats-bugs%netbsd.org@localhost
 > To: kern-bug-people%netbsd.org@localhost, gnats-admin%netbsd.org@localhost,
 >     netbsd-bugs%netbsd.org@localhost, 6bone%6bone.informatik.uni-leipzig.de@localhost
 > Subject: [Extern] Re: kern/58422: kernel crash when using the iscsi initiator
 > 
 > The following reply was made to PR kern/58422; it has been noted by GNATS.
 >
 > From: mlelstv%serpens.de@localhost (Michael van Elst)
 > To: gnats-bugs%netbsd.org@localhost
 > Cc:
 > Subject: Re: kern/58422: kernel crash when using the iscsi initiator
 > Date: Sat, 13 Jul 2024 07:59:10 -0000 (UTC)
 >
 > 6bone%6bone.informatik.uni-leipzig.de@localhost writes:
 >
 > >NetBSD 6bone.informatik.uni-leipzig.de 10.0_STABLE NetBSD 10.0_STABLE (MYCONF10.gdb) #1: Mon Jul  8 15:34:51 CEST 2024  root%6bone.informatik.uni-leipzig.de@localhost:/usr/obj/sys/arch/amd64/compile/MYCONF10.gdb amd64
 >
 > >[ 85126.220101] cpu2: Begin traceback...
 > >[ 85126.220101] vpanic() at netbsd:vpanic+0x183
 > >[ 85126.220101] panic() at netbsd:panic+0x3c
 > >[ 85126.220101] trap() at netbsd:trap+0xb24
 > >[ 85126.220101] --- trap (number 6) ---
 > >[ 85126.230191] mutex_enter() at netbsd:mutex_enter+0x3e
 > >[ 85126.230191] wake_ccb() at iscsi:wake_ccb+0x8e
 > >[ 85126.230191] iscsi_cleanup_thread() at iscsi:iscsi_cleanup_thread+0x351
 > >[ 85126.230191] cpu2: End traceback...
 >
 >
 > That's a use-after-free, when a connection is shut down.
 >
 > The cleanup thread handles timed out CCBs that have already
 > been freed with the closing connection.
 
 I don't know if it's relevant, but connecting the iscsi initiator occurs 
 without a noticeable message in the dmesg.
 
 After you start using the iscsi device, the messages "S3C1: freeing UNUSED 
 pdu" appear regularly in the dmesg.
 
 This goes on for a few days until the crash.
 
 >
 > Can you try to recreate the crash with a DIAGNOSTIC kernel and/or
 > set the sysctl hw.iscsi.debug to 9 ?
 >
 
 The dump from the bug report already comes from a kernel with DIAGNOSTIC 
 enabled. I will try to cause the crash with hw.iscsi.debug=9.
 
 > It might be easier to recreate if you know how the connection
 > is shut down. Maybe some reconfig or reboot of the iscsi target
 > or some network issue.
 >
 
 The iscsi connection was only started once during boot. Then it ran until 
 it crashed. The iscsi target is a NetApp system that runs very stable. I 
 think a network problem is unlikely.
 
 
 Thank you for your efforts
 
 Regards
 Uwe