diff options
author | Alban Bedel <albeu@free.fr> | 2020-04-23 06:35:23 +0300 |
---|---|---|
committer | Petr Štetiar <ynezz@true.cz> | 2020-05-21 16:58:46 +0300 |
commit | 89fb6136ad7484e4e8f9b618e530e098cf573665 (patch) | |
tree | dfdeba8aae0fbb603125d3ab9b5b93434d0375fe /runqueue.h | |
parent | 1db3e7df31d9f0ab24bcaa3fd17e81a9f3104615 (diff) |
libubox: runqueue: fix use-after-free bug
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>
Diffstat (limited to 'runqueue.h')
-rw-r--r-- | runqueue.h | 2 |
1 files changed, 1 insertions, 1 deletions
@@ -63,7 +63,7 @@ struct runqueue_task_type { /* * called to kill a task. must not make any calls to runqueue_task_complete, - * it has already been removed from the list. + * which will be called after this returns. */ void (*kill)(struct runqueue *q, struct runqueue_task *t); }; |