From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 C1C1C23D7CF; Wed, 28 Jan 2026 17:37:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769621852; cv=none; b=ReQHOTubko4iAhYJm7XXvkv8pdDZeJfrTPwhWhkpkMIVG8L/XX7RcHMerXq+ZOLFq50C7Ray0q2Yc+ifY432fYPDAu+cL87Dc88dNzhHsuiEx1q6FtfceMuD8pDmTYeT5QbHCyLPzQ6OKykNfaWf3ULnshiofDcRPMyLvMWLhlE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769621852; c=relaxed/simple; bh=dPWJLUX+E5arRKPqAAl005CIEzPSi/GQ4NP5PfhUX0o=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=oNScsjHotj1EWOtHdliCYlxYzR112Hq182/ST2E2E6qHOaSMXN5E3MSVA+8Ps/+mRYv06Qv1U05nzZrXCWfg+BkoUhi+LNGjrrlmN6jSXKI4q0HKSszf1jUbODvlLz9qvqilCSb/QetgeXF9Bi33OVs5qVpmMj74yorLmpKmWqo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=MVN+Dj7M; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="MVN+Dj7M" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A53F7C4CEF1; Wed, 28 Jan 2026 17:37:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1769621852; bh=dPWJLUX+E5arRKPqAAl005CIEzPSi/GQ4NP5PfhUX0o=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=MVN+Dj7MQ76/SsLr0Llr/J0BJdYUydK/TqMvzASv5tzRovg14PwvBmmFLyvuPTbQY 1OGt7J7Ad8LTFGHU56bN1yeeFmJeB54eMWlZsAhH8up/7GwIUR6OmJ3obJnDdQXfkA qNRp1iLLledv1ZhcyeqVZWZg3x10za7iIPxhAkdk+ESgfbiWDou4xvzaIAQDgVCIph qGLso9Ke5M3qQthAQZOGBhIL4boWOEl557Bu5lK9USRFCyXnQvU+OZl4Zo6XiAC8xD jak+hh+ORU4FjR0TU9e4L6qAjeDNgSBabgT+OJ09bIY+L/A5fboX20feJ5YCdq6Xwf k1MRIXVduRhag== Date: Wed, 28 Jan 2026 17:37:28 +0000 From: Simon Horman To: Henry Zhang Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, tglx@linutronix.de, mingo@kernel.org, syzbot+c6e7bcea7ffb7ff46acb@syzkaller.appspotmail.com, Henry Zhang , Eric Dumazet Subject: Re: [PATCH net] mISDN: Fix data race in timer handling Message-ID: References: <20260127071927.1520272-1-zeri@umich.edu> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260127071927.1520272-1-zeri@umich.edu> + Eric On Tue, Jan 27, 2026 at 02:19:27AM -0500, Henry Zhang wrote: > KCSAN reported a data race where misdn_add_timer() writes dev->work > while mISDN_read() reads it without holding the spinlock: > > write to 0xffff88812d848280 of 4 bytes by task 10864 on cpu 1: > misdn_add_timer drivers/isdn/mISDN/timerdev.c:175 [inline] > ... > > read to 0xffff88812d848280 of 4 bytes by task 10857 on cpu 0: > mISDN_read+0x1f2/0x470 drivers/isdn/mISDN/timerdev.c:112 > ... > > dev->work is read locklessly in wait_event_interruptible() and > mISDN_poll(). In mISDN_read(), the result is rechecked under dev->lock. > In mISDN_poll(), a stale value may cause a spurious EPOLLIN or a missed > wake, but wake_up_interruptible() will correct this. In both cases, the > race is benign, so we can annotate these with READ_ONCE/WRITE_ONCE. > > Reported-by: syzbot+c6e7bcea7ffb7ff46acb@syzkaller.appspotmail.com > Closes: https://syzkaller.appspot.com/bug?extid=c6e7bcea7ffb7ff46acb > > Signed-off-by: Henry Zhang Hi Henry, This appears to already be addressed by commit 8175dbf174d4 ("mISDN: annotate data-race around dev->work") -- pw-bot: cr