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 A0E93473C80; Fri, 24 Jul 2026 22:30:37 +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=1784932239; cv=none; b=Dd6Lt5K/sUukAzrbFbsoTvkPrcZshwwKWgEGoqITeDzR00NYv89IeEdlTBCim9n1yPSTQopTc22hfdkXcq0YsMRKIxZYZoU/iQYFWWMFTJnvROtvgM8WK55Wkt3wA0zSekrbzJU6HfZgXmkT3Ktr7Wu6JYFdksARx/2YQrMT0fM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784932239; c=relaxed/simple; bh=Gmq7d7Jg9C0o7Jvo2rDo8fBZ5JsOa9IPQMlU3RrGn94=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition:In-Reply-To; b=aHVY+p7FLIJgOk5W2+/OyFzkJ5k8706AHohV9lw/vJpHfME4e8zYjP07EX6my8KZfACUAeZBwtFD/7LamOsE6IuVsgoDG9VW3Qou5CGpajuJYnkFv92h8fr7TcKimd2CkM9GALU1PW5kvnfzeJCmepVLvxj6aeU3L1aEckHGZNM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Kg0rN4VN; 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="Kg0rN4VN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4B40B1F00A3A; Fri, 24 Jul 2026 22:30:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784932236; bh=GS14DZQhW66q/6Q+X41QrQ1/gqGz9PBB64fXYqWc4+A=; h=Date:From:To:Cc:Subject:In-Reply-To; b=Kg0rN4VNZ6bV24H8SvNLXOhE+5jjor+DqTtJly6ByqD6Q0sM0vxfACb688tRlkE1q wjyKLglL9XwupGMR66ysdyTevHPvfSH+frGOISUTH4KavpyI0Lh/jPD+u7McPOXNmr cvRkSvmFUY2KGqROQSWSPngkxP/UbcDEzyMHHCWxHuDvS+ofDdvv6uC3OFDhFoxSsi mjfisqiO3UnipsNxl4hBMB2oOHn4243tNZpYLTGywhA86qUHF6rD9Jm97to+SU1ZwD zP7U+v/AqkntG2svYeCMp6iaxn+Tz4/MeoQWDbi+YyqcX/0VzDERrTXU6cl4ybbR03 SnHpJDvqQGwGA== Date: Fri, 24 Jul 2026 17:30:35 -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 v4 9/9] PCI: Fix UAF when probe runs concurrent to dyn ID removal Message-ID: <20260724223035.GA1068309@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: <20260723-pci_id_fix-v4-9-3580726844e1@garyguo.net> On Thu, Jul 23, 2026 at 11:00:48PM +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") > Reviewed-by: Danilo Krummrich > Signed-off-by: Gary Guo Acked-by: Bjorn Helgaas > --- > drivers/pci/pci-driver.c | 28 +++++++++++++++------------- > include/linux/pci.h | 1 + > 2 files changed, 16 insertions(+), 13 deletions(-) > > diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c > index ab3bb756ce89..e16aa59dd7ac 100644 > --- a/drivers/pci/pci-driver.c > +++ b/drivers/pci/pci-driver.c > @@ -180,6 +180,7 @@ static const struct pci_device_id pci_device_id_any = { > * pci_match_device - See if a device matches a driver's list of IDs > * @drv: the PCI driver to match against > * @dev: the PCI device structure to match against > + * @id_copy: place to store copy of pci_device_id for dynamic ID > * > * Used by a driver to check whether a PCI device is in its list of > * supported devices or in the dynids list, which may have been augmented > @@ -187,9 +188,9 @@ static const struct pci_device_id pci_device_id_any = { > * structure or %NULL if there is no match. > */ > static const struct pci_device_id *pci_match_device(struct pci_driver *drv, > - struct pci_dev *dev) > + struct pci_dev *dev, > + struct pci_device_id *id_copy) > { > - struct pci_dynid *dynid; > const struct pci_device_id *found_id = NULL; > struct pci_device_id dev_id; > int ret; > @@ -201,17 +202,16 @@ static const struct pci_device_id *pci_match_device(struct pci_driver *drv, > > dev_id = pci_id_from_device(dev); > /* Look at the dynamic ids first, before the static ones */ > - spin_lock(&drv->dynids.lock); > - list_for_each_entry(dynid, &drv->dynids.list, node) { > - if (pci_match_one_id(&dynid->id, &dev_id)) { > - found_id = &dynid->id; > - break; > + scoped_guard(spinlock, &drv->dynids.lock) { > + struct pci_dynid *dynid; > + > + list_for_each_entry(dynid, &drv->dynids.list, node) { > + if (pci_match_one_id(&dynid->id, &dev_id)) { > + *id_copy = dynid->id; > + return id_copy; > + } > } > } > - spin_unlock(&drv->dynids.lock); > - > - if (found_id) > - return found_id; > > found_id = do_pci_match_id(drv->id_table, &dev_id, ret > 0); > if (found_id) > @@ -467,12 +467,13 @@ void pci_probe_flush_workqueue(void) > static int __pci_device_probe(struct pci_driver *drv, struct pci_dev *pci_dev) > { > const struct pci_device_id *id; > + struct pci_device_id id_copy; > int error = 0; > > if (drv->probe) { > error = -ENODEV; > > - id = pci_match_device(drv, pci_dev); > + id = pci_match_device(drv, pci_dev, &id_copy); > if (id) > error = pci_call_probe(drv, pci_dev, id); > } > @@ -1560,12 +1561,13 @@ static int pci_bus_match(struct device *dev, const struct device_driver *drv) > struct pci_dev *pci_dev = to_pci_dev(dev); > struct pci_driver *pci_drv; > const struct pci_device_id *found_id; > + struct pci_device_id id_copy; > > if (pci_dev_binding_disallowed(pci_dev)) > return 0; > > pci_drv = (struct pci_driver *)to_pci_driver(drv); > - found_id = pci_match_device(pci_drv, pci_dev); > + found_id = pci_match_device(pci_drv, pci_dev, &id_copy); > if (found_id) > return 1; > > 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 always gets called from process > * context, so it can sleep. > * @remove: The remove() function gets called whenever a device > > -- > 2.54.0 >