APPLIED[Unstable]: [SRU][Cosmic][Bionic][PATCH 0/6] Fixes for LP1797367

[Seth Forshee]

On Wed, Nov 07, 2018 at 07:20:40PM +0100, Frank Heimes wrote:
> BugLink: http://bugs.launchpad.net/bugs/1797367
> 
> == SRU Justification ==
> 
> While running a series of stress tests for network on a bond device on
> Ubuntu 18.04.1 with kernel 4.15.0-36.39,
> kernel panic is observed (btw. also on non-bond devices).
> This looks like a race between disabling a qeth device and accessing debugfs.
> This is critical and leads repeatedly to a crash (sooner or later).
> 
> == Fix ==
> 
> e19e5be8b4ca ("s390/qeth: sanitize strings in debug messages")
> 
> pre-reqs:
> 750b162 ("s390/qeth: reduce hard-coded access to ccw channels")
> d857e11 ("s390/qeth: remove outdated portname debug msg")
> 9d0a58f ("s390/qeth: avoid using is_multicast_ether_addr_64bits on (u8 *)[6]")
> 8174aa8 ("s390/qeth: consolidate qeth MAC address helpers")
> 4641b02 ("s390/qeth: don't keep track of MAC address's cast type")
> 
> == Regression Potential ==
> 
> Low, because:
> - limited to s390x
> - and furthermore limited to qeth driver
> - patches a problem identified during testing
> - fix was tested by IBM before submitted
> 
> == Test Case ==
> 
> run:
>    #!/bin/bash
>    var=0
>    while :
>    do
>         var=$((var + 1))
>         echo "DBG count is $var"
>         mkdir /tmp/DBGINFO
>         dbginfo.sh -d /tmp/DBGINFO
>         rm -rf /tmp/DBGINFO*
>         echo "chzdev now is $var"
>         chzdev -e <qeth device>
>         chzdev -d <qeth device>
>    done
> and in avg. in less than 20 cycles a crash happens (usually < 10).

Applied patch 1 to unstable/master, the prerequisites were already
present. Thanks!