From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 2347E3C455F for ; Mon, 6 Jul 2026 23:40:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783381247; cv=none; b=SU+9lywE1/AU0+na0UdQnSPfQPD65RD2QzEL3aAHfHC+D/atZZXJlYGdNltDBYNjRqoGEdOwZHOQjssQ4rMGjMOxj0YfckjUD9CScyLs+8yKHmd29Y79Wqp2y7NdF0MXoYT1yiZjWRj8xYNQqVdmWyJpid2XbEmw+uPsBNjp0Sg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783381247; c=relaxed/simple; bh=dSWJjOhtqbm/+atXQtTfCA6m55tAUZITjPx9llwEBBs=; h=Date:Message-ID:From:To:Cc:Subject:In-Reply-To:References; b=iguBxGN0LMO3WXftDkSvg1kM5yW3lbDMqp2JnzvSlkRDV5b54/7AwWFg+eO18nJ82FWiifAWBF48pSQRcfXZaAUgIaTZe0AgDVxland0H6QiqNWrwyhlRuDkPn6VnUNlo/ietSgB6qrZbkbLKfXQs91Ub7fr5yoUoVBxOETs6tw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=TgDR46mw; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="TgDR46mw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D63621F000E9; Mon, 6 Jul 2026 23:40:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783381246; bh=dSWJjOhtqbm/+atXQtTfCA6m55tAUZITjPx9llwEBBs=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=TgDR46mw2DH0BoI+iFEO0nUxRUpdbs06zs2xvDo3k2PYTfl4lE4Z6UlukzVJHDqDW 9r/Q7asIcWXCWGFDuy7gDnT6tBqn9LikIrP/AdsphbdGh9g/JgcY5mWcJ9rgYBT5AA FhdvY+nq4sV5Y8Tmdw15SvAap0f9r6z8VY5fS40yE9AVEJBUg3RQSHsXivq5vfw2pV ksmf3cOETEBG4pHOx7BSBA0a31JQMggkVD6d2xz5Z1JsTyTI3DhkBWSu2D1OXfUR0F FhQkbULplTcG8idTc8ZRz8te3o4ki5Jal/LlQ5AadFwJeSzRwL6jBBi8pP3KA439hD 5tbuSG62sABxA== Date: Mon, 06 Jul 2026 13:40:45 -1000 Message-ID: <24f272c542021d564cdc6ebd063765bd@kernel.org> From: Tejun Heo To: sashiko-bot@kernel.org Cc: sched-ext@lists.linux.dev Subject: Re: [PATCH v2 sched_ext/for-7.3 21/36] sched_ext: Maintain per-cpu effective cap copies for single-read checks In-Reply-To: <20260706020759.4A2101F000E9@smtp.kernel.org> References: <20260706014058.439853-1-tj@kernel.org> <20260706014058.439853-22-tj@kernel.org> <20260706020759.4A2101F000E9@smtp.kernel.org> Precedence: bulk X-Mailing-List: sched-ext@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: On Mon, 06 Jul 2026 02:07:58 +0000, sashiko-bot wrote: > - [High] Asynchronous processing of `ecaps_to_sync` races with a new scheduler's `scx_cid_init()`, causing slab out-of-bounds reads in `scx_process_sync_ecaps()`. > - [High] `queue_sync_ecaps()` causes a NULL pointer dereference by passing the global `scx_root` pointer to `scx_kick_cpu()` during scheduler teardown. Both false positives. 21-1: the cid read is gated by an llist_empty() check and the sync is pre-drained under cpus_read_lock, so cid == -1 can't index the array. 21-2: scx_root is cleared only after drain + cid-type disable + synchronize_rcu(), and these kfuncs run under guard(irqsave), so scx_root is non-NULL when they run.