On top of
[PATCH 1/3] posix-timers: don't switch to ->group_leader if ->it_process dies
http://marc.info/?l=linux-kernel&m=121778560719812
[PATCH 2/3] posix-timers: always do get_task_struct(timer->it_process)
http://marc.info/?l=linux-kernel&m=121778560719816
checkpatch.pl criticizes the first patch (line over 80 characters), but
that line was just moved by this patch. Not sure what should be done in
such a case, but this line is killed by the next patch anyway.
I don't know how to test these changes. Fortunately they are rather simple,
and the first patch obviously fixes the bug.
Oleg.