path: root/drivers/pnp/pnpacpi/core.c
diff options
authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2012-11-30 13:05:05 +0100
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2012-11-30 13:05:05 +0100
commita6b5e88c0e42093b9057856f35770966c8c591e3 (patch)
tree9b0297d198ce8e690f10a61eec044532b55ea06c /drivers/pnp/pnpacpi/core.c
parentd0c2ce16bec0afa6013b4c5220ca4c9c67210215 (diff)
ACPI / PNP: Do not crash due to stale pointer use during system resume
During resume from system suspend the 'data' field of struct pnp_dev in pnpacpi_set_resources() may be a stale pointer, due to removal of the associated ACPI device node object in the previous suspend-resume cycle. This happens, for example, if a dockable machine is booted in the docking station and then suspended and resumed and suspended again. If that happens, pnpacpi_build_resource_template() called from pnpacpi_set_resources() attempts to use that pointer and crashes. However, pnpacpi_set_resources() actually checks the device's ACPI handle, attempts to find the ACPI device node object attached to it and returns an error code if that fails, so in fact it knows what the correct value of dev->data should be. Use this observation to update dev->data with the correct value if necessary and dump a call trace if that's the case (once). We still need to fix the root cause of this issue, but preventing systems from crashing because of it is an improvement too. Reported-and-tested-by: Zdenek Kabelac <zdenek.kabelac@gmail.com> References: https://bugzilla.kernel.org/show_bug.cgi?id=51071 Cc: <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/pnp/pnpacpi/core.c')
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/pnp/pnpacpi/core.c b/drivers/pnp/pnpacpi/core.c
index 26b5d4b18dd7..ec8e914f756c 100644
--- a/drivers/pnp/pnpacpi/core.c
+++ b/drivers/pnp/pnpacpi/core.c
@@ -95,6 +95,9 @@ static int pnpacpi_set_resources(struct pnp_dev *dev)
return -ENODEV;
+ if (WARN_ON_ONCE(acpi_dev != dev->data))
+ dev->data = acpi_dev;
ret = pnpacpi_build_resource_template(dev, &buffer);
if (ret)
return ret;