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 34B6C44C4EF; Thu, 23 Jul 2026 19:29:58 +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=1784835001; cv=none; b=TFP8qnAXV78gwF1BD4jlEw5Kdx1czmHtQFQqgkGcyqaU3zrO9wI7KBmMJooq5zqTrRbBH6TOiJN7tKa+GbkgKgALEd1obC5pJdidU51Y29Au5U7mdJvz7PHHhsLmu5VhGWA4lePtysdQmOzPZ0UrrRphXbMJQAA8WDlc1sGImMY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784835001; c=relaxed/simple; bh=TwWA1xCcEzuUuBFTE0AMItQB+YBiuWATuf/SC44C6OA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=am88LIu0U9+7tz1JPKfAky6CoQGTwl5dN+hm51DsCr+xBIuGiUci0M4CF74Jr4nY8/qMQyO+PoRAuPeBwglAmtF//QfVOX75fLjAIsUgcfBBglV9FUfTiRMPr2KkeDCjqGj3LyKcB/a1ZbNQBH0J1Q+3zbeSY0Wgj+UoSe5sfCw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=HpztF2W+; 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="HpztF2W+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A0B281F000E9; Thu, 23 Jul 2026 19:29:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784834998; bh=y5iomjCyRfRp3uujqn1eS42YOTWw+ABmMrptepvIZ7Q=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=HpztF2W+jj+oPJBXBd5DBcqoA2Sm/XtLNAo7A3jLOwKkr8x9d2LlNJc5kOK87NXwV dPfvFf436Ag4QAWvE4hqB+0CIaIog+ggZsQ3mr/KoGuZeT7PauU3CUF+DKT/KQGiyw FLRRMPX6Juqw8TE9zKGvvEkK/N74UmZpHbG6YXAMajMDzSW4qR095hChwpIimswuz5 FmKTpz2ndXcBDeMV9c1wUZAFhLPoXzpKXNHeFyf3bAsS8jduYzwuQq95Gtem2ReCoX 4ZUVJbFHzbprLyxqinE64Imvapcq2pUpbKd09SDGjMeT0bBsnsCnQuBqAreyPWS7mS DJoSCkrUJGJnA== Date: Thu, 23 Jul 2026 14:29:57 -0500 From: Bjorn Helgaas To: Gary Guo Cc: Bjorn Helgaas , Zhenzhong Duan , Greg Kroah-Hartman , "Rafael J. Wysocki" , Danilo Krummrich , Damien Le Moal , Niklas Cassel , GOTO Masanori , YOKOTA Hiroshi , "James E.J. Bottomley" , "Martin K. Petersen" , Vaibhav Gupta , Jens Taprogge , Ido Schimmel , Petr Machata , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , David Airlie , linux-pci@vger.kernel.org, driver-core@lists.linux.dev, linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org, linux-scsi@vger.kernel.org, industrypack-devel@lists.sourceforge.net, netdev@vger.kernel.org, dri-devel@lists.freedesktop.org, Sashiko Subject: Re: [PATCH v3 9/9] pci: fix UAF when probe runs concurrent to dyn ID removal Message-ID: <20260723192957.GA839273@bhelgaas> References: <20260706-pci_id_fix-v3-9-2d48fc025acc@garyguo.net> <20260721223500.GA690676@bhelgaas> Precedence: bulk X-Mailing-List: driver-core@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Thu, Jul 23, 2026 at 07:57:58PM +0100, Gary Guo wrote: > On Tue Jul 21, 2026 at 11:35 PM BST, Bjorn Helgaas wrote: > > On Mon, Jul 06, 2026 at 03:11:21PM +0100, Gary Guo wrote: > >> Dynamic IDs are only guaranteed to be valid when dynids.lock is held, > >> as remove_id_store can free the node. Thus, make a copy in > >> pci_match_device. Also, clarify that the id parameter is only valid during > >> probe. > >> > >> Reported-by: Sashiko > >> Link: https://lore.kernel.org/all/20260619170503.518F61F00A3A@smtp.kernel.org/ > >> Fixes: 0994375e9614 ("PCI: add remove_id sysfs entry") > >> Signed-off-by: Gary Guo > >> --- > >> drivers/pci/pci-driver.c | 28 +++++++++++++++------------- > >> include/linux/pci.h | 1 + > >> 2 files changed, 16 insertions(+), 13 deletions(-) > >> > >> diff --git a/include/linux/pci.h b/include/linux/pci.h > >> index 64b308b6e61c..92c17c116de6 100644 > >> --- a/include/linux/pci.h > >> +++ b/include/linux/pci.h > >> @@ -979,6 +979,7 @@ struct module; > >> * function returns zero when the driver chooses to > >> * take "ownership" of the device or an error code > >> * (negative number) otherwise. > >> + * The pci_device_id parameter is only valid during probe. > > > > The probe function takes a pointer to a struct pci_device_id, so I > > think the requirement is that the struct pci_device_id only *needs* to > > be valid during .probe(), right, i.e., the PCI core probe path makes > > its own copy of the ID and doesn't retain the pointer after .probe() > > returns, right? > > > > I assume the caller determines the struct pci_device_id lifetime, and > > it could be forever. > > > > Could say something like: > > > > The pci_device_id parameter only needs to be valid during probe. > > As a contract on function parameter, the caller needs to guarantee that it lives > at least as long as documented (i.e. during the whole probe) and the callee > cannot assume that it will be valid beyond what's guaranteed. > > How about: > > The pci_device_id parameter is only guaranteed to be valid during probe. That's ok with me. My only niggle is that this documentation is that the *consumer* end, and of course the consumer, i.e., the PCI core probe path, can't guarantee anything about the parameters it receives. But I guess your point is that the *caller* must guarantee that the parameter remains valid during probe. The only thing the consumer can guarantee is that it doesn't depend on the pci_device_id parameter after the probe returns.