From: "Schmid, Carsten" <Carsten_Schmid@mentor.com>
To: Mathias Nyman <mathias.nyman@linux.intel.com>,
Hans de Goede <hdegoede@redhat.com>
Cc: "linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>
Subject: [Patch v4] usb: hcd: fix use-after-free on driver removal
Date: Fri, 23 Aug 2019 10:06:01 +0000 [thread overview]
Message-ID: <1566554761464.60146@mentor.com> (raw)
On driver removal, the platform_device_unregister call
attached through devm_add_action_or_reset was executed
after usb_hcd_pci_remove.
This lead to a use-after-free for the iomem resource of
the xhci-ext-caps driver in the platform removal
because the parent of the resource was freed earlier.
Fix this by using devm for hcd-pci created resources.
This simplifies error handling on driver initialisation
and fixes the removal sequence.
Signed-off-by: Carsten Schmid <carsten_schmid@mentor.com>
Tested-by: Carsten Schmid <carsten_schmid@mentor.com>
---
Rationale:
Use-after-free was reproduced on 4.14.102 and 4.14.129 kernel
using unbind mechanism.
echo 0000:00:15.0 > /sys/bus/pci/drivers/xhci_hcd/unbind
Upstream version of driver is identical in the affected code.
Fix was tested successfully on 4.14.129.
Provided patch applies and compiles on v5.2.8 stable.
As this is a bugfix, please consider it to go to stable trees too.
---
v2:
- more speaking name for private data element
- consider failure in driver init sequence
- fix minor issues found by checkpatch.pl
v3:
- corrected typo: resorce -> resource
- added Reviewed by and Tested-by
v4:
- completely rewritten to use devm resource allocation
in hcd-pci
- modified title to better reflect change content
- removed Reviewed-by
[old title: usb: xhci-pci: reorder removal to avoid use-after-free]
---
drivers/usb/core/hcd-pci.c | 30 ++++++++----------------------
1 file changed, 8 insertions(+), 22 deletions(-)
diff --git a/drivers/usb/core/hcd-pci.c b/drivers/usb/core/hcd-pci.c
index 03432467b05f..7537681355f6 100644
--- a/drivers/usb/core/hcd-pci.c
+++ b/drivers/usb/core/hcd-pci.c
@@ -216,17 +216,18 @@ int usb_hcd_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
/* EHCI, OHCI */
hcd->rsrc_start = pci_resource_start(dev, 0);
hcd->rsrc_len = pci_resource_len(dev, 0);
- if (!request_mem_region(hcd->rsrc_start, hcd->rsrc_len,
- driver->description)) {
+ if (!devm_request_mem_region(&dev->dev, hcd->rsrc_start,
+ hcd->rsrc_len, driver->description)) {
dev_dbg(&dev->dev, "controller already in use\n");
retval = -EBUSY;
goto put_hcd;
}
- hcd->regs = ioremap_nocache(hcd->rsrc_start, hcd->rsrc_len);
+ hcd->regs = devm_ioremap_nocache(&dev->dev, hcd->rsrc_start,
+ hcd->rsrc_len);
if (hcd->regs == NULL) {
dev_dbg(&dev->dev, "error mapping memory\n");
retval = -EFAULT;
- goto release_mem_region;
+ goto put_hcd;
}
} else {
@@ -240,8 +241,8 @@ int usb_hcd_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
hcd->rsrc_start = pci_resource_start(dev, region);
hcd->rsrc_len = pci_resource_len(dev, region);
- if (request_region(hcd->rsrc_start, hcd->rsrc_len,
- driver->description))
+ if (devm_request_region(&dev->dev, hcd->rsrc_start,
+ hcd->rsrc_len, driver->description))
break;
}
if (region == PCI_ROM_RESOURCE) {
@@ -275,20 +276,13 @@ int usb_hcd_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
}
if (retval != 0)
- goto unmap_registers;
+ goto put_hcd;
device_wakeup_enable(hcd->self.controller);
if (pci_dev_run_wake(dev))
pm_runtime_put_noidle(&dev->dev);
return retval;
-unmap_registers:
- if (driver->flags & HCD_MEMORY) {
- iounmap(hcd->regs);
-release_mem_region:
- release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
- } else
- release_region(hcd->rsrc_start, hcd->rsrc_len);
put_hcd:
usb_put_hcd(hcd);
disable_pci:
@@ -347,14 +341,6 @@ void usb_hcd_pci_remove(struct pci_dev *dev)
dev_set_drvdata(&dev->dev, NULL);
up_read(&companions_rwsem);
}
-
- if (hcd->driver->flags & HCD_MEMORY) {
- iounmap(hcd->regs);
- release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
- } else {
- release_region(hcd->rsrc_start, hcd->rsrc_len);
- }
-
usb_put_hcd(hcd);
pci_disable_device(dev);
}
--
2.17.1
next reply other threads:[~2019-08-23 10:06 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-23 10:06 Schmid, Carsten [this message]
2019-08-23 13:36 ` [Patch v4] usb: hcd: fix use-after-free on driver removal Mathias Nyman
2019-08-23 13:42 ` AW: " Schmid, Carsten
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