From nobody Sun Oct 5 20:11:54 2025 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 28B5526E140 for ; Wed, 30 Jul 2025 10:33:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753871611; cv=none; b=N9EyVpGBd8WWu1hZ/daewcdDio2MC/nPwA/GeHt9ntxU66UfUADvXNnmjpBakW+oebnNYPbp6gd6msj3yY7sINaX87r+j/whIPk+kGZCn/nOzL/Er6qJ7rQF6I+Sc7yGcVae3EB2I+GQcZN8fGuucUDPLjBa+dRruKOMvql/5IM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753871611; c=relaxed/simple; bh=Mgtm+AZHgtiboO81D2klozRHFXTt27P6lDtPoA5yoPY=; h=Message-ID:Date:MIME-Version:To:Cc:From:Subject:Content-Type; b=qYkLJweaho886r9TD0HKVh9Bnhl26382MYHRcupKJU7pi4RvC0cKiVmyJoGWRCX1hYBg0A29ayTmwo/+SlOyCnH7EoaKCioyG3ELDReAhYjTBU2SepQtf6bujnFrrhXfUOKuq8ssiwJ1FdHniHZxcBl0weH8oXL7oH7m6eHQ00g= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 962ED1BC0; Wed, 30 Jul 2025 03:33:20 -0700 (PDT) Received: from [192.168.3.124] (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id E9ACD3F673; Wed, 30 Jul 2025 03:33:26 -0700 (PDT) Message-ID: <43a9cbdc-5121-4dc8-8438-0f01c90a4687@arm.com> Date: Wed, 30 Jul 2025 11:33:19 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Content-Language: en-US To: arighi@nvidia.com, Tejun Heo , David Vernet Cc: sched-ext@lists.linux.dev, "linux-kernel@vger.kernel.org" , Ingo Molnar , Peter Zijlstra From: Christian Loehle Subject: [PATCHv2] sched_ext: Mark scx_bpf_cpu_rq as NULL returnable Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" scx_bpf_cpu_rq() obviously returns NULL on invalid cpu. Mark it as such. While kf_cpu_valid() will trigger scx_ops_error() that leads to the BPF scheduler exiting, this isn't guaranteed to be immediate, allowing for a dereference of a NULL scx_bpf_cpu_rq() return value. Cc: stable@vger.kernel.org Fixes: 6203ef73fa5c ("sched/ext: Add BPF function to fetch rq") Signed-off-by: Christian Loehle Acked-by: Andrea Righi --- v2: Extended commit message and picked up Andrea's ACK. kernel/sched/ext.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c index 7dd5cbcb7a06..b734f55f3318 100644 --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -7599,7 +7599,7 @@ BTF_ID_FLAGS(func, scx_bpf_get_online_cpumask, KF_ACQ= UIRE) BTF_ID_FLAGS(func, scx_bpf_put_cpumask, KF_RELEASE) BTF_ID_FLAGS(func, scx_bpf_task_running, KF_RCU) BTF_ID_FLAGS(func, scx_bpf_task_cpu, KF_RCU) -BTF_ID_FLAGS(func, scx_bpf_cpu_rq) +BTF_ID_FLAGS(func, scx_bpf_cpu_rq, KF_RET_NULL) #ifdef CONFIG_CGROUP_SCHED BTF_ID_FLAGS(func, scx_bpf_task_cgroup, KF_RCU | KF_ACQUIRE) #endif --=20 2.34.1