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Mon, 02 Feb 2026 23:38:05 -0800 (PST) Received: from host.td.teradata.com ([2600:1700:7c:96e0:f36c:cc80:2358:72ca]) by smtp.gmail.com with ESMTPSA id 956f58d0204a3-649c195cd7fsm5570268d50.15.2026.02.02.23.38.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 02 Feb 2026 23:38:04 -0800 (PST) From: Altan Hacigumus To: akpm@linux-foundation.org, david@fromorbit.com Cc: ahacigu.linux@gmail.com, zhengqi.arch@bytedance.com, roman.gushchin@linux.dev, muchun.song@linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH] mm/shrinker: Fix refcount leak in shrink_slab_memcg() Date: Mon, 2 Feb 2026 23:37:57 -0800 Message-ID: <20260203073757.135088-1-ahacigu.linux@gmail.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" 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 Acked-by: Qi Zheng --- 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, =20 /* 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; + } =20 ret =3D do_shrink_slab(&sc, shrinker, priority); if (ret =3D=3D SHRINK_EMPTY) { --=20 2.43.0