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McKenney" , Josh Triplett , Boqun Feng , Uladzislau Rezki , Steven Rostedt , Mathieu Desnoyers , Lai Jiangshan , Zqiang , Dmitry Vyukov , rcu@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20260324-kasan-kfree-rcu-v1-1-ac58a7a13d03@google.com> Content-Language: en-US From: Joel Fernandes In-Reply-To: <20260324-kasan-kfree-rcu-v1-1-ac58a7a13d03@google.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-ClientProxiedBy: CYZPR12CA0009.namprd12.prod.outlook.com (2603:10b6:930:8b::24) To DS0PR12MB6486.namprd12.prod.outlook.com (2603:10b6:8:c5::21) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DS0PR12MB6486:EE_|CYYPR12MB8889:EE_ X-MS-Office365-Filtering-Correlation-Id: c9a5c7fc-397b-41ae-3303-08de8a1b01b7 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|366016|1800799024|7416014|22082099003|18002099003|7053199007|56012099003; 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for example, the following testcase doesn't trigger a KASAN splat > when CONFIG_KVFREE_RCU_BATCHED is enabled: > ``` > struct foo_struct { > struct rcu_head rcu; > int a; > }; > struct foo_struct *foo = kmalloc(sizeof(*foo), > GFP_KERNEL | __GFP_NOFAIL | __GFP_ZERO); > > pr_info("%s: calling kfree_rcu()\n", __func__); > kfree_rcu(foo, rcu); > msleep(10); > pr_info("%s: start UAF access\n", __func__); > READ_ONCE(foo->a); > pr_info("%s: end UAF access\n", __func__); > ``` > > Signed-off-by: Jann Horn Reviewed-by: Joel Fernandes