Fixes a use-after-free bug in runqueue_task_kill():
Invalid read of size 8
at runqueue_task_kill (runqueue.c:200)
by uloop_process_timeouts (uloop.c:505)
by uloop_run_timeout (uloop.c:542)
by uloop_run (uloop.h:111)
by main (tests/test-runqueue.c:126)
Address 0x5a4b058 is 24 bytes inside a block of size 208 free'd
at free
by runqueue_task_complete (runqueue.c:234)
by runqueue_task_kill (runqueue.c:199)
by uloop_process_timeouts (uloop.c:505)
by uloop_run_timeout (uloop.c:542)
by uloop_run (uloop.h:111)
by main (tests/test-runqueue.c:126)
Block was alloc'd at
at calloc
by add_sleeper (tests/test-runqueue.c:101)
by main (tests/test-runqueue.c:123)
Since commit 11e8afea (runqueue should call the complete handler from
more places) the call to the complete() callback has been moved to
runqueue_task_complete(). However in runqueue_task_kill()
runqueue_task_complete() is called before the kill() callback. This
will result in a use after free if the complete() callback frees the
task struct.
Furthermore runqueue_start_next() is already called at the end of
runqueue_task_complete(), so there is no need to call it again in
runqueue_task_kill().
The issue was that the _complete() callback frees the memory used by the
task struct, which is then read after the _complete() callback returns.
Ref: FS#3016
Signed-off-by: Alban Bedel <albeu@free.fr>
[initial test case, kill cb comment fix]
Signed-off-by: Chris Nisbet <nischris@gmail.com>
[testcase improvements and commit subject/description tweaks]
Signed-off-by: Petr Štetiar <ynezz@true.cz>
The comment relating to the runqueue task structure 'cancel' callback
indicated that the callback 'calls' runqueue_task_complete, which
isn't quite right. The callback _should_ call runqueue_task_complete.
Signed-off-by: Chris Nisbet <nischris@gmail.com>
