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Sat, 15 Feb 2025 08:57:04 -0800 (PST) Received: from localhost ([2a02:587:860a:7219:38f1:eba9:54d5:df1f]) by smtp.gmail.com with UTF8SMTPSA id a640c23a62f3a-aba5a4f4cb4sm481480966b.118.2025.02.15.08.57.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 15 Feb 2025 08:57:03 -0800 (PST) Date: Sat, 15 Feb 2025 18:57:01 +0200 From: Lilitha Persefoni Gkini To: Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Vlastimil Babka , Roman Gushchin , Hyeonggon Yoo <42.hyeyoo@gmail.com>, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH] slub: Fix Off-By-One in the While condition in on_freelist() Message-ID: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The condition `nr <=3D slab->objects` in the `on_freelist()` serves as bound while walking through the `freelist` linked list because we can't have more free objects than the maximum amount of objects in the slab. But the `=3D` can result in an extra unnecessary iteration. The patch changes it to `nr < slab->objects` to ensure it iterates at most `slab->objects` number of times. Signed-off-by: Lilitha Persefoni Gkini --- mm/slub.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/slub.c b/mm/slub.c index 1f50129dcfb3..ad42450d4b0f 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -1435,7 +1435,7 @@ static int on_freelist(struct kmem_cache *s, struct s= lab *slab, void *search) int max_objects; =20 fp =3D slab->freelist; - while (fp && nr <=3D slab->objects) { + while (fp && nr < slab->objects) { if (fp =3D=3D search) return 1; if (!check_valid_pointer(s, slab, fp)) { --=20 2.48.1