From nobody Sat Oct 4 01:39:28 2025 Received: from dggsgout12.his.huawei.com (dggsgout12.his.huawei.com [45.249.212.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F365C2E7F35; Fri, 22 Aug 2025 07:22:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.56 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755847325; cv=none; b=VZ3NY5FNQHlFmEV0qlRXWz7v2YSztg46u7Jr4VuhmxXxeJjZdH3A2L2eNRSWZJpQidOxyd0zvrNBwFYOuCbQtL+is9TJAZmL1i4o1DuVziU91M8CrsLTh9saX8l5Ul7uNewkK2TLGqU5sfT/fIRNwkl3gcj1rJUpEFvzfJFLlzM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755847325; c=relaxed/simple; bh=kf0YriOisQDJMpG0e4pstGk2K6sgCqPA/LCOQWMUv98=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=hl7kMp3Gfe9QgYvSi7ITcTXSY37hsU3Ysioo/RGjyxw4utb6pWnUMNr+LwQ2nmfoHiLTAPsMMK8xUpPLOLwWgqdCb0yeKxsoM4GKg0FJsC/XExMs9DbE2MAPdckf/4xLv+xu3rnM7/w03C16JgrAskN1Oldl0YCgRto0CdBVCfA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.163.235]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTPS id 4c7Wpd6tw8zKHNdK; Fri, 22 Aug 2025 15:22:01 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.75]) by mail.maildlp.com (Postfix) with ESMTP id 737601A07FA; Fri, 22 Aug 2025 15:22:01 +0800 (CST) Received: from hulk-vt.huawei.com (unknown [10.67.174.121]) by APP2 (Coremail) with SMTP id Syh0CgC3w7WJGqho3fPWEQ--.9949S4; Fri, 22 Aug 2025 15:21:59 +0800 (CST) From: Chen Ridong To: gregkh@linuxfoundation.org, tj@kernel.org, hannes@cmpxchg.org, mkoutny@suse.com, peterz@infradead.org, zhouchengming@bytedance.com Cc: linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, lujialin4@huawei.com, chenridong@huawei.com, libaokun1@huawei.com Subject: [PATCH v2 2/2] cgroup/psi: Set of->priv to NULL upon file release Date: Fri, 22 Aug 2025 07:07:15 +0000 Message-Id: <20250822070715.1565236-3-chenridong@huaweicloud.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20250822070715.1565236-1-chenridong@huaweicloud.com> References: <20250822070715.1565236-1-chenridong@huaweicloud.com> 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 X-CM-TRANSID: Syh0CgC3w7WJGqho3fPWEQ--.9949S4 X-Coremail-Antispam: 1UD129KBjvdXoW7XrWUAw45tw1kZr1rXF43Wrg_yoWDWFg_Ca 40vr1qgryxAw47Kw1DZws3AFWkKa98WF4vqw1rKFW7JF15Jr4kJwsaqrn8ZrsrZa18Gr15 Zr93Krn2qFnxJjkaLaAFLSUrUUUUjb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUbBxYFVCjjxCrM7AC8VAFwI0_Wr0E3s1l1xkIjI8I6I8E6xAIw20E Y4v20xvaj40_Wr0E3s1l1IIY67AEw4v_Jr0_Jr4l82xGYIkIc2x26280x7IE14v26r15M2 8IrcIa0xkI8VCY1x0267AKxVW5JVCq3wA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK 021l84ACjcxK6xIIjxv20xvE14v26w1j6s0DM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r 4UJVWxJr1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_ GcCE3s1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx 0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7xkEbVWU JVW8JwACjcxG0xvY0x0EwIxGrwACI402YVCY1x02628vn2kIc2xKxwCY1x0262kKe7AKxV WUtVW8ZwCF04k20xvY0x0EwIxGrwCF54CYxVCY1x0262kKe7AKxVWUtVW8ZwCFx2IqxVCF s4IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r 1rMI8E67AF67kF1VAFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWU JVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Cr0_Gr1UMIIF0xvE42xK8VAvwI8IcIk0rV WUJVWUCwCI42IY6I8E87Iv67AKxVWUJVW8JwCI42IY6I8E87Iv6xkF7I0E14v26r4UJVWx JrUvcSsGvfC2KfnxnUUI43ZEXa7IU1VT5JUUUUU== X-CM-SenderInfo: hfkh02xlgr0w46kxt4xhlfz01xgou0bp/ Content-Type: text/plain; charset="utf-8" From: Chen Ridong Setting of->priv to NULL when the file is released enables earlier bug detection. This allows potential bugs to manifest as NULL pointer dereferences rather than use-after-free errors[1], which are generally more difficult to diagnose. [1] https://lore.kernel.org/cgroups/38ef3ff9-b380-44f0-9315-8b3714b0948d@hu= aweicloud.com/T/#m8a3b3f88f0ff3da5925d342e90043394f8b2091b Signed-off-by: Chen Ridong --- kernel/cgroup/cgroup.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 312c6a8b55bb..d8b82afed181 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -4159,6 +4159,7 @@ static void cgroup_file_release(struct kernfs_open_fi= le *of) cft->release(of); put_cgroup_ns(ctx->ns); kfree(ctx); + of->priv =3D NULL; } =20 static ssize_t cgroup_file_write(struct kernfs_open_file *of, char *buf, --=20 2.34.1