[PATCH] mm/shrinker: Fix refcount leak in shrink_slab_memcg()
From: Altan Hacigumus
Date: Tue Feb 03 2026 - 02:38:09 EST
When kmem is disabled for memcg, slab-backed shrinkers are skipped.
However, shrink_slab_memcg() doesn't drop the reference acquired via
shrinker_try_get() before continuing.
Add the missing shrinker_put().
Fixes: 50d09da8e119 ("mm: shrinker: make memcg slab shrink lockless")
Signed-off-by: Altan Hacigumus <ahacigu.linux@xxxxxxxxx>
---
mm/shrinker.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/mm/shrinker.c b/mm/shrinker.c
index 4a93fd433689..d0be120488b4 100644
--- a/mm/shrinker.c
+++ b/mm/shrinker.c
@@ -544,8 +544,10 @@ static unsigned long shrink_slab_memcg(gfp_t gfp_mask, int nid,
/* Call non-slab shrinkers even though kmem is disabled */
if (!memcg_kmem_online() &&
- !(shrinker->flags & SHRINKER_NONSLAB))
+ !(shrinker->flags & SHRINKER_NONSLAB)) {
+ shrinker_put(shrinker);
continue;
+ }
ret = do_shrink_slab(&sc, shrinker, priority);
if (ret == SHRINK_EMPTY) {
--
2.43.0