Revision 647e82dbf85124697be59a4b4cf00c0d38177dcb authored by Andy Shevchenko on 01 September 2022, 11:34:06 UTC, committed by Hans de Goede on 01 September 2022, 15:51:34 UTC
We have to copy only selected fields from the original resource. Because a PCI device will be removed immediately after getting its resources, we may not use any allocated data, hence we may not copy any pointers. Consider the following scenario: 1/ a caller of p2sb_bar() gets the resource; 2/ the resource has been copied by platform_device_add_data() in order to create a platform device; 3/ the platform device creation will call for the device driver's ->probe() as soon as a match found; 4/ the ->probe() takes given resources (see 2/) and tries to access one of its field, i.e. 'name', in the __devm_ioremap_resource() to create a pretty looking output; 5/ but the 'name' is a dangling pointer because p2sb_bar() removed a PCI device, which 'name' had been copied to the caller's memory. 6/ UAF (Use-After-Free) as a result. Kudos to Mika for the initial analisys of the issue. Fixes: 9745fb07474f ("platform/x86/intel: Add Primary to Sideband (P2SB) bridge support") Reported-by: kernel test robot <oliver.sang@intel.com> Suggested-by: Mika Westerberg <mika.westerberg@linux.intel.com> Link: https://lore.kernel.org/linux-i2c/YvPCbnKqDiL2XEKp@xsang-OptiPlex-9020/ Link: https://lore.kernel.org/linux-i2c/YtjAswDKfiuDfWYs@xsang-OptiPlex-9020/ Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20220901113406.65876-1-andriy.shevchenko@linux.intel.com Reviewed-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
1 parent 5542dfc
edac_module.c
/*
* edac_module.c
*
* (C) 2007 www.softwarebitmaker.com
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*
* Author: Doug Thompson <dougthompson@xmission.com>
*
*/
#include <linux/edac.h>
#include "edac_mc.h"
#include "edac_module.h"
#define EDAC_VERSION "Ver: 3.0.0"
#ifdef CONFIG_EDAC_DEBUG
static int edac_set_debug_level(const char *buf,
const struct kernel_param *kp)
{
unsigned long val;
int ret;
ret = kstrtoul(buf, 0, &val);
if (ret)
return ret;
if (val > 4)
return -EINVAL;
return param_set_int(buf, kp);
}
/* Values of 0 to 4 will generate output */
int edac_debug_level = 2;
EXPORT_SYMBOL_GPL(edac_debug_level);
module_param_call(edac_debug_level, edac_set_debug_level, param_get_int,
&edac_debug_level, 0644);
MODULE_PARM_DESC(edac_debug_level, "EDAC debug level: [0-4], default: 2");
#endif
/*
* edac_op_state_to_string()
*/
char *edac_op_state_to_string(int opstate)
{
if (opstate == OP_RUNNING_POLL)
return "POLLED";
else if (opstate == OP_RUNNING_INTERRUPT)
return "INTERRUPT";
else if (opstate == OP_RUNNING_POLL_INTR)
return "POLL-INTR";
else if (opstate == OP_ALLOC)
return "ALLOC";
else if (opstate == OP_OFFLINE)
return "OFFLINE";
return "UNKNOWN";
}
/*
* sysfs object: /sys/devices/system/edac
* need to export to other files
*/
static struct bus_type edac_subsys = {
.name = "edac",
.dev_name = "edac",
};
static int edac_subsys_init(void)
{
int err;
/* create the /sys/devices/system/edac directory */
err = subsys_system_register(&edac_subsys, NULL);
if (err)
printk(KERN_ERR "Error registering toplevel EDAC sysfs dir\n");
return err;
}
static void edac_subsys_exit(void)
{
bus_unregister(&edac_subsys);
}
/* return pointer to the 'edac' node in sysfs */
struct bus_type *edac_get_sysfs_subsys(void)
{
return &edac_subsys;
}
EXPORT_SYMBOL_GPL(edac_get_sysfs_subsys);
/*
* edac_init
* module initialization entry point
*/
static int __init edac_init(void)
{
int err = 0;
edac_printk(KERN_INFO, EDAC_MC, EDAC_VERSION "\n");
err = edac_subsys_init();
if (err)
return err;
/*
* Harvest and clear any boot/initialization PCI parity errors
*
* FIXME: This only clears errors logged by devices present at time of
* module initialization. We should also do an initial clear
* of each newly hotplugged device.
*/
edac_pci_clear_parity_errors();
err = edac_mc_sysfs_init();
if (err)
goto err_sysfs;
edac_debugfs_init();
err = edac_workqueue_setup();
if (err) {
edac_printk(KERN_ERR, EDAC_MC, "Failure initializing workqueue\n");
goto err_wq;
}
return 0;
err_wq:
edac_debugfs_exit();
edac_mc_sysfs_exit();
err_sysfs:
edac_subsys_exit();
return err;
}
/*
* edac_exit()
* module exit/termination function
*/
static void __exit edac_exit(void)
{
edac_dbg(0, "\n");
/* tear down the various subsystems */
edac_workqueue_teardown();
edac_mc_sysfs_exit();
edac_debugfs_exit();
edac_subsys_exit();
}
/*
* Inform the kernel of our entry and exit points
*/
subsys_initcall(edac_init);
module_exit(edac_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Doug Thompson www.softwarebitmaker.com, et al");
MODULE_DESCRIPTION("Core library routines for EDAC reporting");
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