From: SeongJae Park <sj@xxxxxxxxxx> commit 5f1fc67f2cb8d3035d3acd273b48b97835af8afd upstream. damos_new_filter() is not initializing the list field of newly allocated filter object. However, DAMON sysfs interface and DAMON_RECLAIM are not initializing it after calling damos_new_filter(). As a result, accessing uninitialized memory is possible. Actually, adding multiple DAMOS filters via DAMON sysfs interface caused NULL pointer dereferencing. Initialize the field just after the allocation from damos_new_filter(). Link: https://lkml.kernel.org/r/20230729203733.38949-2-sj@xxxxxxxxxx Fixes: 98def236f63c ("mm/damon/core: implement damos filter") Signed-off-by: SeongJae Park <sj@xxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- mm/damon/core.c | 1 + 1 file changed, 1 insertion(+) diff --git a/mm/damon/core.c b/mm/damon/core.c index 91cff7f2997e..eb9580942a5c 100644 --- a/mm/damon/core.c +++ b/mm/damon/core.c @@ -273,6 +273,7 @@ struct damos_filter *damos_new_filter(enum damos_filter_type type, return NULL; filter->type = type; filter->matching = matching; + INIT_LIST_HEAD(&filter->list); return filter; } -- 2.41.0
