From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) (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 297603FB072 for ; Wed, 25 Mar 2026 17:54:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=216.40.44.11 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774461300; cv=none; b=VvpITluUbkkgcNMP9n7GOmuOoMgmrDbXODcaIGtS1QdK1Ek8pyONkIBkZyKzYO26RyJwMyJ9bCFZ30JEF7YpujrEGz2c9bbAfoHxwhbeNsWaAggWnUC7tb3wQU8SR2YDwqPMWzBsa+G3BqQm6hzAD3SBhuieMuriv4Ko3shPjTg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774461300; c=relaxed/simple; bh=f5pFZ2a2Xnwx1EdPsyp036XPOu4bBWmc3uSYKf0zl18=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=n776yOHu/L5quElV2LZBryubQAD95tHV6M1bAUOgE6JoVLhUz/XNYgH7SFr88Akh1dzF5nNR8DsfgKjDp2oWGDvNSYxRhsVxacf8odeVm6OnN/gfEk8vKZbgtQwkWyuBEYajzAgr99XLXQhkwCgqJVcM3asAxN5WKuUPmCide8k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=goodmis.org; spf=pass smtp.mailfrom=goodmis.org; arc=none smtp.client-ip=216.40.44.11 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=goodmis.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=goodmis.org Received: from omf13.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id A2E245B94E; Wed, 25 Mar 2026 17:54:57 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: rostedt@goodmis.org) by omf13.hostedemail.com (Postfix) with ESMTPA id A0A2D20012; Wed, 25 Mar 2026 17:54:55 +0000 (UTC) Date: Wed, 25 Mar 2026 13:55:40 -0400 From: Steven Rostedt To: Sebastian Andrzej Siewior Cc: Jiayuan Chen , linux-rt-devel@lists.linux.dev, Clark Williams , linux-kernel@vger.kernel.org, "Paul E. McKenney" Subject: Re: [PATCH v1] irq_work: Fix use-after-free in irq_work_single on PREEMPT_RT Message-ID: <20260325135540.4d127635@gandalf.local.home> In-Reply-To: <20260325175150._IrYQldq@linutronix.de> References: <20260325030508.321405-1-jiayuan.chen@linux.dev> <20260325111351.1d38a0bc@gandalf.local.home> <20260325153826.EbSqlX_n@linutronix.de> <20260325115315.052e34ac@gandalf.local.home> <20260325155504.tm4zHWMI@linutronix.de> <5b6f6480-aa2d-4966-b3c7-6c719e915285@linux.dev> <20260325170539.MHkr49jU@linutronix.de> <20260325134433.7d46507d@gandalf.local.home> <20260325175150._IrYQldq@linutronix.de> X-Mailer: Claws Mail 3.20.0git84 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: A0A2D20012 X-Rspamd-Server: rspamout06 X-Stat-Signature: 3xqribss3nc4e65mitudhqwscbynupao X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX18IaNsPSiZdPSiw/bPwbqbxMdboncrkBp4= X-HE-Tag: 1774461295-227127 X-HE-Meta: U2FsdGVkX18JQhYjCe7nRQ4Iyn+1MXfd97Ct/Qs9jVOvPsFOQw0KCokxi0R192MiosBSCPV0xZJns0Omhcy8YuoXTj1datK/70FvLAXQFiyHlIK20JxYP4uPeb1v5VvTN28OaFzorS1+yoFee9USCfSWUQWg1QKskQatTO9lXZP291mNc4VPav9YlhvtEA1IBznPxK/q++GVa0Ud/UuE5xQ3chr5PcOz/eOzkMGbi5m93y4oCPHGvZbPsL6S31IvbD7fGZ3vdKR6c4mRlXRz7fdayJ8IeCn3OTaQN5Xv/75wLJy2x59NKFfMYOwPNjeJ On Wed, 25 Mar 2026 18:51:50 +0100 Sebastian Andrzej Siewior wrote: > > Perhaps Jiayuan's idea is better as it will not require modifying current > > callers and does fix the issue. > > Don't you need to replace irq_work_sync() with this new one? > > > But it would still need helper functions from RCU as I really do not think > > it's a good idea to open code the rcuwait logic. > > Why is rcuwait a concern? Oh, I was talking about how the patch open coded rcuwait (which we shouldn't do). Are you saying that if we stick a synchronize_rcu() in irq_work_sync() that could work too? -- Steve