linux_dsm_epyc7002/drivers/edac/ghes_edac.c
James Morse 1e72e673b9 EDAC/ghes: Fix Use after free in ghes_edac remove path
ghes_edac models a single logical memory controller, and uses a global
ghes_init variable to ensure only the first ghes_edac_register() will
do anything.

ghes_edac is registered the first time a GHES entry in the HEST is
probed. There may be multiple entries, so subsequent attempts to
register ghes_edac are silently ignored as the work has already been
done.

When a GHES entry is unregistered, it calls ghes_edac_unregister(),
which free()s the memory behind the global variables in ghes_edac.

But there may be multiple GHES entries, the next call to
ghes_edac_unregister() will dereference the free()d memory, and attempt
to free it a second time.

This may also be triggered on a platform with one GHES entry, if the
driver is unbound/re-bound and unbound. The re-bind step will do
nothing because of ghes_init, the second unbind will then do the same
work as the first.

Doing the unregister work on the first call is unsafe, as another
CPU may be processing a notification in ghes_edac_report_mem_error(),
using the memory we are about to free.

ghes_init is already half of the reference counting. We only need
to do the register work for the first call, and the unregister work
for the last. Add the unregister check.

This means we no longer free ghes_edac's memory while there are
GHES entries that may receive a notification.

This was detected by KASAN and DEBUG_TEST_DRIVER_REMOVE.

 [ bp: merge into a single patch. ]

Fixes: 0fe5f281f7 ("EDAC, ghes: Model a single, logical memory controller")
Reported-by: John Garry <john.garry@huawei.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Robert Richter <rrichter@marvell.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20191014171919.85044-2-james.morse@arm.com
Link: https://lkml.kernel.org/r/304df85b-8b56-b77e-1a11-aa23769f2e7c@huawei.com
2019-10-17 11:27:05 +02:00

564 lines
14 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* GHES/EDAC Linux driver
*
* Copyright (c) 2013 by Mauro Carvalho Chehab
*
* Red Hat Inc. http://www.redhat.com
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <acpi/ghes.h>
#include <linux/edac.h>
#include <linux/dmi.h>
#include "edac_module.h"
#include <ras/ras_event.h>
struct ghes_edac_pvt {
struct list_head list;
struct ghes *ghes;
struct mem_ctl_info *mci;
/* Buffers for the error handling routine */
char detail_location[240];
char other_detail[160];
char msg[80];
};
static atomic_t ghes_init = ATOMIC_INIT(0);
static struct ghes_edac_pvt *ghes_pvt;
/*
* Sync with other, potentially concurrent callers of
* ghes_edac_report_mem_error(). We don't know what the
* "inventive" firmware would do.
*/
static DEFINE_SPINLOCK(ghes_lock);
/* "ghes_edac.force_load=1" skips the platform check */
static bool __read_mostly force_load;
module_param(force_load, bool, 0);
/* Memory Device - Type 17 of SMBIOS spec */
struct memdev_dmi_entry {
u8 type;
u8 length;
u16 handle;
u16 phys_mem_array_handle;
u16 mem_err_info_handle;
u16 total_width;
u16 data_width;
u16 size;
u8 form_factor;
u8 device_set;
u8 device_locator;
u8 bank_locator;
u8 memory_type;
u16 type_detail;
u16 speed;
u8 manufacturer;
u8 serial_number;
u8 asset_tag;
u8 part_number;
u8 attributes;
u32 extended_size;
u16 conf_mem_clk_speed;
} __attribute__((__packed__));
struct ghes_edac_dimm_fill {
struct mem_ctl_info *mci;
unsigned int count;
};
static void ghes_edac_count_dimms(const struct dmi_header *dh, void *arg)
{
int *num_dimm = arg;
if (dh->type == DMI_ENTRY_MEM_DEVICE)
(*num_dimm)++;
}
static int get_dimm_smbios_index(u16 handle)
{
struct mem_ctl_info *mci = ghes_pvt->mci;
int i;
for (i = 0; i < mci->tot_dimms; i++) {
if (mci->dimms[i]->smbios_handle == handle)
return i;
}
return -1;
}
static void ghes_edac_dmidecode(const struct dmi_header *dh, void *arg)
{
struct ghes_edac_dimm_fill *dimm_fill = arg;
struct mem_ctl_info *mci = dimm_fill->mci;
if (dh->type == DMI_ENTRY_MEM_DEVICE) {
struct memdev_dmi_entry *entry = (struct memdev_dmi_entry *)dh;
struct dimm_info *dimm = EDAC_DIMM_PTR(mci->layers, mci->dimms,
mci->n_layers,
dimm_fill->count, 0, 0);
u16 rdr_mask = BIT(7) | BIT(13);
if (entry->size == 0xffff) {
pr_info("Can't get DIMM%i size\n",
dimm_fill->count);
dimm->nr_pages = MiB_TO_PAGES(32);/* Unknown */
} else if (entry->size == 0x7fff) {
dimm->nr_pages = MiB_TO_PAGES(entry->extended_size);
} else {
if (entry->size & BIT(15))
dimm->nr_pages = MiB_TO_PAGES((entry->size & 0x7fff) << 10);
else
dimm->nr_pages = MiB_TO_PAGES(entry->size);
}
switch (entry->memory_type) {
case 0x12:
if (entry->type_detail & BIT(13))
dimm->mtype = MEM_RDDR;
else
dimm->mtype = MEM_DDR;
break;
case 0x13:
if (entry->type_detail & BIT(13))
dimm->mtype = MEM_RDDR2;
else
dimm->mtype = MEM_DDR2;
break;
case 0x14:
dimm->mtype = MEM_FB_DDR2;
break;
case 0x18:
if (entry->type_detail & BIT(12))
dimm->mtype = MEM_NVDIMM;
else if (entry->type_detail & BIT(13))
dimm->mtype = MEM_RDDR3;
else
dimm->mtype = MEM_DDR3;
break;
case 0x1a:
if (entry->type_detail & BIT(12))
dimm->mtype = MEM_NVDIMM;
else if (entry->type_detail & BIT(13))
dimm->mtype = MEM_RDDR4;
else
dimm->mtype = MEM_DDR4;
break;
default:
if (entry->type_detail & BIT(6))
dimm->mtype = MEM_RMBS;
else if ((entry->type_detail & rdr_mask) == rdr_mask)
dimm->mtype = MEM_RDR;
else if (entry->type_detail & BIT(7))
dimm->mtype = MEM_SDR;
else if (entry->type_detail & BIT(9))
dimm->mtype = MEM_EDO;
else
dimm->mtype = MEM_UNKNOWN;
}
/*
* Actually, we can only detect if the memory has bits for
* checksum or not
*/
if (entry->total_width == entry->data_width)
dimm->edac_mode = EDAC_NONE;
else
dimm->edac_mode = EDAC_SECDED;
dimm->dtype = DEV_UNKNOWN;
dimm->grain = 128; /* Likely, worse case */
/*
* FIXME: It shouldn't be hard to also fill the DIMM labels
*/
if (dimm->nr_pages) {
edac_dbg(1, "DIMM%i: %s size = %d MB%s\n",
dimm_fill->count, edac_mem_types[dimm->mtype],
PAGES_TO_MiB(dimm->nr_pages),
(dimm->edac_mode != EDAC_NONE) ? "(ECC)" : "");
edac_dbg(2, "\ttype %d, detail 0x%02x, width %d(total %d)\n",
entry->memory_type, entry->type_detail,
entry->total_width, entry->data_width);
}
dimm->smbios_handle = entry->handle;
dimm_fill->count++;
}
}
void ghes_edac_report_mem_error(int sev, struct cper_sec_mem_err *mem_err)
{
enum hw_event_mc_err_type type;
struct edac_raw_error_desc *e;
struct mem_ctl_info *mci;
struct ghes_edac_pvt *pvt = ghes_pvt;
unsigned long flags;
char *p;
u8 grain_bits;
if (!pvt)
return;
/*
* We can do the locking below because GHES defers error processing
* from NMI to IRQ context. Whenever that changes, we'd at least
* know.
*/
if (WARN_ON_ONCE(in_nmi()))
return;
spin_lock_irqsave(&ghes_lock, flags);
mci = pvt->mci;
e = &mci->error_desc;
/* Cleans the error report buffer */
memset(e, 0, sizeof (*e));
e->error_count = 1;
strcpy(e->label, "unknown label");
e->msg = pvt->msg;
e->other_detail = pvt->other_detail;
e->top_layer = -1;
e->mid_layer = -1;
e->low_layer = -1;
*pvt->other_detail = '\0';
*pvt->msg = '\0';
switch (sev) {
case GHES_SEV_CORRECTED:
type = HW_EVENT_ERR_CORRECTED;
break;
case GHES_SEV_RECOVERABLE:
type = HW_EVENT_ERR_UNCORRECTED;
break;
case GHES_SEV_PANIC:
type = HW_EVENT_ERR_FATAL;
break;
default:
case GHES_SEV_NO:
type = HW_EVENT_ERR_INFO;
}
edac_dbg(1, "error validation_bits: 0x%08llx\n",
(long long)mem_err->validation_bits);
/* Error type, mapped on e->msg */
if (mem_err->validation_bits & CPER_MEM_VALID_ERROR_TYPE) {
p = pvt->msg;
switch (mem_err->error_type) {
case 0:
p += sprintf(p, "Unknown");
break;
case 1:
p += sprintf(p, "No error");
break;
case 2:
p += sprintf(p, "Single-bit ECC");
break;
case 3:
p += sprintf(p, "Multi-bit ECC");
break;
case 4:
p += sprintf(p, "Single-symbol ChipKill ECC");
break;
case 5:
p += sprintf(p, "Multi-symbol ChipKill ECC");
break;
case 6:
p += sprintf(p, "Master abort");
break;
case 7:
p += sprintf(p, "Target abort");
break;
case 8:
p += sprintf(p, "Parity Error");
break;
case 9:
p += sprintf(p, "Watchdog timeout");
break;
case 10:
p += sprintf(p, "Invalid address");
break;
case 11:
p += sprintf(p, "Mirror Broken");
break;
case 12:
p += sprintf(p, "Memory Sparing");
break;
case 13:
p += sprintf(p, "Scrub corrected error");
break;
case 14:
p += sprintf(p, "Scrub uncorrected error");
break;
case 15:
p += sprintf(p, "Physical Memory Map-out event");
break;
default:
p += sprintf(p, "reserved error (%d)",
mem_err->error_type);
}
} else {
strcpy(pvt->msg, "unknown error");
}
/* Error address */
if (mem_err->validation_bits & CPER_MEM_VALID_PA) {
e->page_frame_number = mem_err->physical_addr >> PAGE_SHIFT;
e->offset_in_page = mem_err->physical_addr & ~PAGE_MASK;
}
/* Error grain */
if (mem_err->validation_bits & CPER_MEM_VALID_PA_MASK)
e->grain = ~(mem_err->physical_addr_mask & ~PAGE_MASK);
/* Memory error location, mapped on e->location */
p = e->location;
if (mem_err->validation_bits & CPER_MEM_VALID_NODE)
p += sprintf(p, "node:%d ", mem_err->node);
if (mem_err->validation_bits & CPER_MEM_VALID_CARD)
p += sprintf(p, "card:%d ", mem_err->card);
if (mem_err->validation_bits & CPER_MEM_VALID_MODULE)
p += sprintf(p, "module:%d ", mem_err->module);
if (mem_err->validation_bits & CPER_MEM_VALID_RANK_NUMBER)
p += sprintf(p, "rank:%d ", mem_err->rank);
if (mem_err->validation_bits & CPER_MEM_VALID_BANK)
p += sprintf(p, "bank:%d ", mem_err->bank);
if (mem_err->validation_bits & CPER_MEM_VALID_ROW)
p += sprintf(p, "row:%d ", mem_err->row);
if (mem_err->validation_bits & CPER_MEM_VALID_COLUMN)
p += sprintf(p, "col:%d ", mem_err->column);
if (mem_err->validation_bits & CPER_MEM_VALID_BIT_POSITION)
p += sprintf(p, "bit_pos:%d ", mem_err->bit_pos);
if (mem_err->validation_bits & CPER_MEM_VALID_MODULE_HANDLE) {
const char *bank = NULL, *device = NULL;
int index = -1;
dmi_memdev_name(mem_err->mem_dev_handle, &bank, &device);
if (bank != NULL && device != NULL)
p += sprintf(p, "DIMM location:%s %s ", bank, device);
else
p += sprintf(p, "DIMM DMI handle: 0x%.4x ",
mem_err->mem_dev_handle);
index = get_dimm_smbios_index(mem_err->mem_dev_handle);
if (index >= 0) {
e->top_layer = index;
e->enable_per_layer_report = true;
}
}
if (p > e->location)
*(p - 1) = '\0';
/* All other fields are mapped on e->other_detail */
p = pvt->other_detail;
if (mem_err->validation_bits & CPER_MEM_VALID_ERROR_STATUS) {
u64 status = mem_err->error_status;
p += sprintf(p, "status(0x%016llx): ", (long long)status);
switch ((status >> 8) & 0xff) {
case 1:
p += sprintf(p, "Error detected internal to the component ");
break;
case 16:
p += sprintf(p, "Error detected in the bus ");
break;
case 4:
p += sprintf(p, "Storage error in DRAM memory ");
break;
case 5:
p += sprintf(p, "Storage error in TLB ");
break;
case 6:
p += sprintf(p, "Storage error in cache ");
break;
case 7:
p += sprintf(p, "Error in one or more functional units ");
break;
case 8:
p += sprintf(p, "component failed self test ");
break;
case 9:
p += sprintf(p, "Overflow or undervalue of internal queue ");
break;
case 17:
p += sprintf(p, "Virtual address not found on IO-TLB or IO-PDIR ");
break;
case 18:
p += sprintf(p, "Improper access error ");
break;
case 19:
p += sprintf(p, "Access to a memory address which is not mapped to any component ");
break;
case 20:
p += sprintf(p, "Loss of Lockstep ");
break;
case 21:
p += sprintf(p, "Response not associated with a request ");
break;
case 22:
p += sprintf(p, "Bus parity error - must also set the A, C, or D Bits ");
break;
case 23:
p += sprintf(p, "Detection of a PATH_ERROR ");
break;
case 25:
p += sprintf(p, "Bus operation timeout ");
break;
case 26:
p += sprintf(p, "A read was issued to data that has been poisoned ");
break;
default:
p += sprintf(p, "reserved ");
break;
}
}
if (mem_err->validation_bits & CPER_MEM_VALID_REQUESTOR_ID)
p += sprintf(p, "requestorID: 0x%016llx ",
(long long)mem_err->requestor_id);
if (mem_err->validation_bits & CPER_MEM_VALID_RESPONDER_ID)
p += sprintf(p, "responderID: 0x%016llx ",
(long long)mem_err->responder_id);
if (mem_err->validation_bits & CPER_MEM_VALID_TARGET_ID)
p += sprintf(p, "targetID: 0x%016llx ",
(long long)mem_err->responder_id);
if (p > pvt->other_detail)
*(p - 1) = '\0';
/* Generate the trace event */
grain_bits = fls_long(e->grain);
snprintf(pvt->detail_location, sizeof(pvt->detail_location),
"APEI location: %s %s", e->location, e->other_detail);
trace_mc_event(type, e->msg, e->label, e->error_count,
mci->mc_idx, e->top_layer, e->mid_layer, e->low_layer,
(e->page_frame_number << PAGE_SHIFT) | e->offset_in_page,
grain_bits, e->syndrome, pvt->detail_location);
edac_raw_mc_handle_error(type, mci, e);
spin_unlock_irqrestore(&ghes_lock, flags);
}
/*
* Known systems that are safe to enable this module.
*/
static struct acpi_platform_list plat_list[] = {
{"HPE ", "Server ", 0, ACPI_SIG_FADT, all_versions},
{ } /* End */
};
int ghes_edac_register(struct ghes *ghes, struct device *dev)
{
bool fake = false;
int rc, num_dimm = 0;
struct mem_ctl_info *mci;
struct edac_mc_layer layers[1];
struct ghes_edac_dimm_fill dimm_fill;
int idx = -1;
if (IS_ENABLED(CONFIG_X86)) {
/* Check if safe to enable on this system */
idx = acpi_match_platform_list(plat_list);
if (!force_load && idx < 0)
return -ENODEV;
} else {
idx = 0;
}
/*
* We have only one logical memory controller to which all DIMMs belong.
*/
if (atomic_inc_return(&ghes_init) > 1)
return 0;
/* Get the number of DIMMs */
dmi_walk(ghes_edac_count_dimms, &num_dimm);
/* Check if we've got a bogus BIOS */
if (num_dimm == 0) {
fake = true;
num_dimm = 1;
}
layers[0].type = EDAC_MC_LAYER_ALL_MEM;
layers[0].size = num_dimm;
layers[0].is_virt_csrow = true;
mci = edac_mc_alloc(0, ARRAY_SIZE(layers), layers, sizeof(struct ghes_edac_pvt));
if (!mci) {
pr_info("Can't allocate memory for EDAC data\n");
return -ENOMEM;
}
ghes_pvt = mci->pvt_info;
ghes_pvt->ghes = ghes;
ghes_pvt->mci = mci;
mci->pdev = dev;
mci->mtype_cap = MEM_FLAG_EMPTY;
mci->edac_ctl_cap = EDAC_FLAG_NONE;
mci->edac_cap = EDAC_FLAG_NONE;
mci->mod_name = "ghes_edac.c";
mci->ctl_name = "ghes_edac";
mci->dev_name = "ghes";
if (fake) {
pr_info("This system has a very crappy BIOS: It doesn't even list the DIMMS.\n");
pr_info("Its SMBIOS info is wrong. It is doubtful that the error report would\n");
pr_info("work on such system. Use this driver with caution\n");
} else if (idx < 0) {
pr_info("This EDAC driver relies on BIOS to enumerate memory and get error reports.\n");
pr_info("Unfortunately, not all BIOSes reflect the memory layout correctly.\n");
pr_info("So, the end result of using this driver varies from vendor to vendor.\n");
pr_info("If you find incorrect reports, please contact your hardware vendor\n");
pr_info("to correct its BIOS.\n");
pr_info("This system has %d DIMM sockets.\n", num_dimm);
}
if (!fake) {
dimm_fill.count = 0;
dimm_fill.mci = mci;
dmi_walk(ghes_edac_dmidecode, &dimm_fill);
} else {
struct dimm_info *dimm = EDAC_DIMM_PTR(mci->layers, mci->dimms,
mci->n_layers, 0, 0, 0);
dimm->nr_pages = 1;
dimm->grain = 128;
dimm->mtype = MEM_UNKNOWN;
dimm->dtype = DEV_UNKNOWN;
dimm->edac_mode = EDAC_SECDED;
}
rc = edac_mc_add_mc(mci);
if (rc < 0) {
pr_info("Can't register at EDAC core\n");
edac_mc_free(mci);
return -ENODEV;
}
return 0;
}
void ghes_edac_unregister(struct ghes *ghes)
{
struct mem_ctl_info *mci;
if (!ghes_pvt)
return;
if (atomic_dec_return(&ghes_init))
return;
mci = ghes_pvt->mci;
ghes_pvt = NULL;
edac_mc_del_mc(mci->pdev);
edac_mc_free(mci);
}