[SRU][Zesty][PATCH 0/1] tty: Prepare for destroying line discipline on hangup

[Joseph Salisbury]

BugLink: http://bugs.launchpad.net/bugs/1721065

== SRU Justification ==
A regression was introduced in Ubuntu kernel 4.4.0-93+ kernels, which causes
a panic.  The panic is caused by a NULL pointer dereference in tty_write().

This regression was introduced by the fix for the bug #17091264: commit 892d1fa
("tty: Destroy ldisc instance on hangup").  However, this commit also needs the
fix for this bug, commit e55afd1 ("tty: Prepare for destroying line discipline on hangup").

Commit e55afd1 is in mainline as of v4.6-rc1.
 
== Fix ==
commit e55afd11a48354c810caf6b6ad4c103016a88230
Author: Peter Hurley <peter at hurleysoftware.com>
Date:   Sun Jan 10 22:41:01 2016 -0800

    tty: Prepare for destroying line discipline on hangup

== Regression Potential ==
This commit has been in mainline since v4.6-rc1, so it has been tested for
some time.
 
== Test Case == 
A test kernel was built with this patch and tested by the original bug reporter.
The bug reporter states the test kernel resolved the bug.


Peter Hurley (1):
  tty: Prepare for destroying line discipline on hangup

 drivers/tty/tty_io.c       | 14 ++++++++++++++
 drivers/tty/tty_ldisc.c    |  4 ++--
 drivers/tty/vt/selection.c |  2 ++
 3 files changed, 18 insertions(+), 2 deletions(-)

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2.7.4