DAMON_LRU_SORT allocates the damon_ctx object for its kdamond in its init function. damon_lru_sort_enabled_store() wrongly assumes the allocation will always succeed once tried. If the damon_ctx allocation was failed, therefore, code execution reaches to damon_commit_ctx() while 'ctx' is NULL. As a result, it dereferences the NULL 'ctx' pointer. Avoid the NULL dereference by returning -ENOMEM if 'ctx' is NULL. Fixes: c4a8e662c839 ("mm/damon/lru_sort: use damon_initialized()") Cc: # 6.18.x Signed-off-by: SeongJae Park --- mm/damon/lru_sort.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/mm/damon/lru_sort.c b/mm/damon/lru_sort.c index eca88ed941b32..8298c6001fd09 100644 --- a/mm/damon/lru_sort.c +++ b/mm/damon/lru_sort.c @@ -476,6 +476,10 @@ static int damon_lru_sort_enabled_store(const char *val, if (!damon_initialized()) return 0; + /* damon_modules_new_paddr_ctx_target() in the init function failed. */ + if (!ctx) + return -ENOMEM; + return damon_lru_sort_turn(enabled); } -- 2.47.3