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 48EB93C47B for ; Tue, 22 Jul 2025 21:46:17 +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=1753220780; cv=none; b=EW/O2JS4oUmdixpEsYUcVShLW2meIS+Z5LjCteOu0Bk4iT8NUtLU3E2V1WmpP3Bvx2tP8ReaXejHFGbE1vTxaAXqQ3w8fxrPWU1NZUOt1Cxg8iGdwKRBfosJCvVIoyGb0ZAzqCfD1h0IGYcmd325lFbvkuViCJUmn6lipbXWFzc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753220780; c=relaxed/simple; bh=b67kSSEKMxeNtlW+zqTKtszmtkQ9YSVQeHWPl1zO8C4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=X/9cp4Z/iebu3QhdbUNRkCyz4RZpoXX28mVgzdvcz23cS2CYG7EdfJi/CrmvBuachUNJJnwmvOLNClgDZ7UKCLKpRrP89CWWcUNga6ljhjR8207hIP8UOBH1wsAFk0PC9eDJaT3u97tq0y6qeoXCmlbynpjUmnpOtyHzvFZuleE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=EhobZqUL; 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="EhobZqUL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DCF35C4CEEB; Tue, 22 Jul 2025 21:46:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1753220777; bh=b67kSSEKMxeNtlW+zqTKtszmtkQ9YSVQeHWPl1zO8C4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EhobZqULaUecg9VlEjuxBEjvqwQS84o2Fgh3YNxw2HpzqrY6DeyeTXwsKr0WPtSGL ThBwUniTr2NX5xatWJaatP4mAmsJTtqOGdTIWFCmxhjiP9vbjzJEz7+CMTbOooIzn0 8WL4et5gMCuJmF2HSVGjQ1aunJJcVyLoKU4pA4/Vk9BhVDJqNcpNlNNBUwVljRM0AV GAeJXwDwbes26FyI/pj6o7klc60RJfrYzZzYmAuRYim915308ObeXNxDS3s3uXFxaR Nd5AtjtCxvimt5ksZ+zTRorLuGHX84Pc5kFexwHDlnwp4kH0yvFGUvAXg92DGIag4V rJ9xOcBfe9cpg== From: Sasha Levin To: stable@vger.kernel.org Cc: Ian Abbott , Greg Kroah-Hartman , Sasha Levin Subject: [PATCH 5.10.y] comedi: comedi_test: Fix possible deletion of uninitialized timers Date: Tue, 22 Jul 2025 17:46:13 -0400 Message-Id: <20250722214613.981170-1-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <2025072155-viper-viewer-98bd@gregkh> References: <2025072155-viper-viewer-98bd@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Ian Abbott [ Upstream commit 1b98304c09a0192598d0767f1eb8c83d7e793091 ] In `waveform_common_attach()`, the two timers `&devpriv->ai_timer` and `&devpriv->ao_timer` are initialized after the allocation of the device private data by `comedi_alloc_devpriv()` and the subdevices by `comedi_alloc_subdevices()`. The function may return with an error between those function calls. In that case, `waveform_detach()` will be called by the Comedi core to clean up. The check that `waveform_detach()` uses to decide whether to delete the timers is incorrect. It only checks that the device private data was allocated, but that does not guarantee that the timers were initialized. It also needs to check that the subdevices were allocated. Fix it. Fixes: 73e0e4dfed4c ("staging: comedi: comedi_test: fix timer lock-up") Cc: stable@vger.kernel.org # 6.15+ Signed-off-by: Ian Abbott Link: https://lore.kernel.org/r/20250708130627.21743-1-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman [ file location from drivers/comedi to drivers/staging/comedi and timer_delete_sync() to del_timer_sync(). ] Signed-off-by: Sasha Levin --- drivers/staging/comedi/drivers/comedi_test.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/staging/comedi/drivers/comedi_test.c b/drivers/staging/comedi/drivers/comedi_test.c index bea9a3adf08c8..f5199474c0e93 100644 --- a/drivers/staging/comedi/drivers/comedi_test.c +++ b/drivers/staging/comedi/drivers/comedi_test.c @@ -790,7 +790,7 @@ static void waveform_detach(struct comedi_device *dev) { struct waveform_private *devpriv = dev->private; - if (devpriv) { + if (devpriv && dev->n_subdevices) { del_timer_sync(&devpriv->ai_timer); del_timer_sync(&devpriv->ao_timer); } -- 2.39.5