On Sun, Dec 26, 2021 at 10:26:32AM +0000, SeongJae Park wrote: > commit 34796417964b8d0aef45a99cf6c2d20cebe33733 upstream. > > DAMON debugfs interface iterates current monitoring targets in > 'dbgfs_target_ids_read()' while holding the corresponding > 'kdamond_lock'. However, it also destructs the monitoring targets in > 'dbgfs_before_terminate()' without holding the lock. This can result in > a use_after_free bug. This commit avoids the race by protecting the > destruction with the corresponding 'kdamond_lock'. > > Link: https://lkml.kernel.org/r/20211221094447.2241-1-sj@xxxxxxxxxx > Reported-by: Sangwoo Bae <sangwoob@xxxxxxxxxx> > Fixes: 4bc05954d007 ("mm/damon: implement a debugfs-based user space interface") > Signed-off-by: SeongJae Park <sj@xxxxxxxxxx> > Cc: <stable@xxxxxxxxxxxxxxx> # 5.15.x > Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> > --- > This is a backport of a DAMON fix that merged in the mainline, for > v5.15.x stable series. Now queued up, thanks. greg k-h
