[PATCH v2 0/2] Fix NULL pointer dereference issue during discovering UPI topology

[PATCH v2 0/2] Fix NULL pointer dereference issue during discovering UPI topology

[alexander.antonov]

From: Alexander Antonov <alexander.antonov@linux.intel.com>

The NULL dereference happens inside upi_fill_topology() procedure in
case of disabling one of the sockets on the system.

For example, if you disable the 2nd socket on a 4-socket system then
uncore_max_dies() returns 3 and inside pmu_alloc_topology() memory will
be allocated only for 3 sockets and stored in type->topology.
In discover_upi_topology() memory is accessed by socket id from CPUNODEID
registers which contain physical ids (from 0 to 3) and on the line:

    upi = &type->topology[nid][idx];

out-of-bound access will happen and the 'upi' pointer will be passed to
upi_fill_topology() where it will be dereferenced.

To avoid this issue update the code to convert physical socket id to
logical socket id in discover_upi_topology() before accessing memory.

Changed in v2:
 1. Factor out topology_gidnid_map() with common code for GIDNIDMAP procedure

Alexander Antonov (2):
  perf/x86/intel/uncore: Fix NULL pointer dereference issue in
    upi_fill_topology()
  perf/x86/intel/uncore: Factor out topology_gidnid_map()

 arch/x86/events/intel/uncore_snbep.c | 71 ++++++++++++++++------------
 1 file changed, 40 insertions(+), 31 deletions(-)

-- 
2.25.1

[PATCH v2 1/2] perf/x86/intel/uncore: Fix NULL pointer dereference issue in upi_fill_topology()

[alexander.antonov]

From: Alexander Antonov <alexander.antonov@linux.intel.com>

Get logical socket id instead of physical id in discover_upi_topology()
to avoid out-of-bound access on 'upi = &type->topology[nid][idx];' line
that leads to NULL pointer dereference in upi_fill_topology()

Fixes: f680b6e6062e ("perf/x86/intel/uncore: Enable UPI topology discovery for Icelake Server")
Reported-by: Kyle Meyer <kyle.meyer@hpe.com>
Tested-by: Kyle Meyer <kyle.meyer@hpe.com>
Signed-off-by: Alexander Antonov <alexander.antonov@linux.intel.com>
---
 arch/x86/events/intel/uncore_snbep.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/arch/x86/events/intel/uncore_snbep.c b/arch/x86/events/intel/uncore_snbep.c
index 8250f0f59c2b..49bc27ab26ad 100644
--- a/arch/x86/events/intel/uncore_snbep.c
+++ b/arch/x86/events/intel/uncore_snbep.c
@@ -5596,7 +5596,7 @@ static int discover_upi_topology(struct intel_uncore_type *type, int ubox_did, i
 	struct pci_dev *ubox = NULL;
 	struct pci_dev *dev = NULL;
 	u32 nid, gid;
-	int i, idx, ret = -EPERM;
+	int i, idx, lgc_pkg, ret = -EPERM;
 	struct intel_uncore_topology *upi;
 	unsigned int devfn;
 
@@ -5614,8 +5614,13 @@ static int discover_upi_topology(struct intel_uncore_type *type, int ubox_did, i
 		for (i = 0; i < 8; i++) {
 			if (nid != GIDNIDMAP(gid, i))
 				continue;
+			lgc_pkg = topology_phys_to_logical_pkg(i);
+			if (lgc_pkg < 0) {
+				ret = -EPERM;
+				goto err;
+			}
 			for (idx = 0; idx < type->num_boxes; idx++) {
-				upi = &type->topology[nid][idx];
+				upi = &type->topology[lgc_pkg][idx];
 				devfn = PCI_DEVFN(dev_link0 + idx, ICX_UPI_REGS_ADDR_FUNCTION);
 				dev = pci_get_domain_bus_and_slot(pci_domain_nr(ubox->bus),
 								  ubox->bus->number,
@@ -5626,6 +5631,7 @@ static int discover_upi_topology(struct intel_uncore_type *type, int ubox_did, i
 						goto err;
 				}
 			}
+			break;
 		}
 	}
 err:
-- 
2.25.1

[tip: perf/core] perf/x86/intel/uncore: Fix NULL pointer dereference issue in upi_fill_topology()

[tip-bot2 for Alexander Antonov]

The following commit has been merged into the perf/core branch of tip:

Commit-ID:     1692cf434ba13ee212495b5af795b6a07e986ce4
Gitweb:        https://git.kernel.org/tip/1692cf434ba13ee212495b5af795b6a07e986ce4
Author:        Alexander Antonov <alexander.antonov@linux.intel.com>
AuthorDate:    Mon, 27 Nov 2023 10:52:45 -08:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Thu, 30 Nov 2023 14:29:52 +01:00

perf/x86/intel/uncore: Fix NULL pointer dereference issue in upi_fill_topology()

Get logical socket id instead of physical id in discover_upi_topology()
to avoid out-of-bound access on 'upi = &type->topology[nid][idx];' line
that leads to NULL pointer dereference in upi_fill_topology()

Fixes: f680b6e6062e ("perf/x86/intel/uncore: Enable UPI topology discovery for Icelake Server")
Reported-by: Kyle Meyer <kyle.meyer@hpe.com>
Signed-off-by: Alexander Antonov <alexander.antonov@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Tested-by: Kyle Meyer <kyle.meyer@hpe.com>
Link: https://lore.kernel.org/r/20231127185246.2371939-2-alexander.antonov@linux.intel.com
---
 arch/x86/events/intel/uncore_snbep.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/arch/x86/events/intel/uncore_snbep.c b/arch/x86/events/intel/uncore_snbep.c
index aeaa8ef..1efbacf 100644
--- a/arch/x86/events/intel/uncore_snbep.c
+++ b/arch/x86/events/intel/uncore_snbep.c
@@ -5596,7 +5596,7 @@ static int discover_upi_topology(struct intel_uncore_type *type, int ubox_did, i
 	struct pci_dev *ubox = NULL;
 	struct pci_dev *dev = NULL;
 	u32 nid, gid;
-	int i, idx, ret = -EPERM;
+	int i, idx, lgc_pkg, ret = -EPERM;
 	struct intel_uncore_topology *upi;
 	unsigned int devfn;
 
@@ -5614,8 +5614,13 @@ static int discover_upi_topology(struct intel_uncore_type *type, int ubox_did, i
 		for (i = 0; i < 8; i++) {
 			if (nid != GIDNIDMAP(gid, i))
 				continue;
+			lgc_pkg = topology_phys_to_logical_pkg(i);
+			if (lgc_pkg < 0) {
+				ret = -EPERM;
+				goto err;
+			}
 			for (idx = 0; idx < type->num_boxes; idx++) {
-				upi = &type->topology[nid][idx];
+				upi = &type->topology[lgc_pkg][idx];
 				devfn = PCI_DEVFN(dev_link0 + idx, ICX_UPI_REGS_ADDR_FUNCTION);
 				dev = pci_get_domain_bus_and_slot(pci_domain_nr(ubox->bus),
 								  ubox->bus->number,
@@ -5626,6 +5631,7 @@ static int discover_upi_topology(struct intel_uncore_type *type, int ubox_did, i
 						goto err;
 				}
 			}
+			break;
 		}
 	}
 err:

[PATCH v2 2/2] perf/x86/intel/uncore: Factor out topology_gidnid_map()

[alexander.antonov]

From: Alexander Antonov <alexander.antonov@linux.intel.com>

The same code is used for retrieving package ID procedure from GIDNIDMAP
register. Factor out topology_gidnid_map() to avoid code duplication.

Signed-off-by: Alexander Antonov <alexander.antonov@linux.intel.com>
---
 arch/x86/events/intel/uncore_snbep.c | 77 +++++++++++++++-------------
 1 file changed, 40 insertions(+), 37 deletions(-)

diff --git a/arch/x86/events/intel/uncore_snbep.c b/arch/x86/events/intel/uncore_snbep.c
index 49bc27ab26ad..3d918147a8a2 100644
--- a/arch/x86/events/intel/uncore_snbep.c
+++ b/arch/x86/events/intel/uncore_snbep.c
@@ -1396,6 +1396,29 @@ static int upi_nodeid_groupid(struct pci_dev *ubox_dev, int nodeid_loc, int idma
 	return ret;
 }
 
+static int topology_gidnid_map(int nodeid, u32 gidnid)
+{
+	int i, die_id = -1;
+
+	/*
+	 * every three bits in the Node ID mapping register maps
+	 * to a particular node.
+	 */
+	for (i = 0; i < 8; i++) {
+		if (nodeid == GIDNIDMAP(gidnid, i)) {
+			if (topology_max_die_per_package() > 1)
+				die_id = i;
+			else
+				die_id = topology_phys_to_logical_pkg(i);
+			if (die_id < 0)
+				die_id = -ENODEV;
+			break;
+		}
+	}
+
+	return die_id;
+}
+
 /*
  * build pci bus to socket mapping
  */
@@ -1435,22 +1458,7 @@ static int snbep_pci2phy_map_init(int devid, int nodeid_loc, int idmap_loc, bool
 				break;
 			}
 
-			/*
-			 * every three bits in the Node ID mapping register maps
-			 * to a particular node.
-			 */
-			for (i = 0; i < 8; i++) {
-				if (nodeid == GIDNIDMAP(config, i)) {
-					if (topology_max_die_per_package() > 1)
-						die_id = i;
-					else
-						die_id = topology_phys_to_logical_pkg(i);
-					if (die_id < 0)
-						die_id = -ENODEV;
-					map->pbus_to_dieid[bus] = die_id;
-					break;
-				}
-			}
+			map->pbus_to_dieid[bus] = topology_gidnid_map(nodeid, config);
 			raw_spin_unlock(&pci2phy_map_lock);
 		} else {
 			segment = pci_domain_nr(ubox_dev->bus);
@@ -5596,7 +5604,7 @@ static int discover_upi_topology(struct intel_uncore_type *type, int ubox_did, i
 	struct pci_dev *ubox = NULL;
 	struct pci_dev *dev = NULL;
 	u32 nid, gid;
-	int i, idx, lgc_pkg, ret = -EPERM;
+	int idx, lgc_pkg, ret = -EPERM;
 	struct intel_uncore_topology *upi;
 	unsigned int devfn;
 
@@ -5611,27 +5619,22 @@ static int discover_upi_topology(struct intel_uncore_type *type, int ubox_did, i
 			break;
 		}
 
-		for (i = 0; i < 8; i++) {
-			if (nid != GIDNIDMAP(gid, i))
-				continue;
-			lgc_pkg = topology_phys_to_logical_pkg(i);
-			if (lgc_pkg < 0) {
-				ret = -EPERM;
-				goto err;
-			}
-			for (idx = 0; idx < type->num_boxes; idx++) {
-				upi = &type->topology[lgc_pkg][idx];
-				devfn = PCI_DEVFN(dev_link0 + idx, ICX_UPI_REGS_ADDR_FUNCTION);
-				dev = pci_get_domain_bus_and_slot(pci_domain_nr(ubox->bus),
-								  ubox->bus->number,
-								  devfn);
-				if (dev) {
-					ret = upi_fill_topology(dev, upi, idx);
-					if (ret)
-						goto err;
-				}
+		lgc_pkg = topology_gidnid_map(nid, gid);
+		if (lgc_pkg < 0) {
+			ret = -EPERM;
+			goto err;
+		}
+		for (idx = 0; idx < type->num_boxes; idx++) {
+			upi = &type->topology[lgc_pkg][idx];
+			devfn = PCI_DEVFN(dev_link0 + idx, ICX_UPI_REGS_ADDR_FUNCTION);
+			dev = pci_get_domain_bus_and_slot(pci_domain_nr(ubox->bus),
+							  ubox->bus->number,
+							  devfn);
+			if (dev) {
+				ret = upi_fill_topology(dev, upi, idx);
+				if (ret)
+					goto err;
 			}
-			break;
 		}
 	}
 err:
-- 
2.25.1

[tip: perf/core] perf/x86/intel/uncore: Factor out topology_gidnid_map()

[tip-bot2 for Alexander Antonov]

The following commit has been merged into the perf/core branch of tip:

Commit-ID:     fdd041028f2294228e10610b4fca6a1a83ac683d
Gitweb:        https://git.kernel.org/tip/fdd041028f2294228e10610b4fca6a1a83ac683d
Author:        Alexander Antonov <alexander.antonov@linux.intel.com>
AuthorDate:    Mon, 27 Nov 2023 10:52:46 -08:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Thu, 30 Nov 2023 14:29:53 +01:00

perf/x86/intel/uncore: Factor out topology_gidnid_map()

The same code is used for retrieving package ID procedure from GIDNIDMAP
register. Factor out topology_gidnid_map() to avoid code duplication.

Signed-off-by: Alexander Antonov <alexander.antonov@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Link: https://lore.kernel.org/r/20231127185246.2371939-3-alexander.antonov@linux.intel.com
---
 arch/x86/events/intel/uncore_snbep.c | 77 ++++++++++++++-------------
 1 file changed, 40 insertions(+), 37 deletions(-)

diff --git a/arch/x86/events/intel/uncore_snbep.c b/arch/x86/events/intel/uncore_snbep.c
index 1efbacf..a96496b 100644
--- a/arch/x86/events/intel/uncore_snbep.c
+++ b/arch/x86/events/intel/uncore_snbep.c
@@ -1396,6 +1396,29 @@ err:
 	return ret;
 }
 
+static int topology_gidnid_map(int nodeid, u32 gidnid)
+{
+	int i, die_id = -1;
+
+	/*
+	 * every three bits in the Node ID mapping register maps
+	 * to a particular node.
+	 */
+	for (i = 0; i < 8; i++) {
+		if (nodeid == GIDNIDMAP(gidnid, i)) {
+			if (topology_max_die_per_package() > 1)
+				die_id = i;
+			else
+				die_id = topology_phys_to_logical_pkg(i);
+			if (die_id < 0)
+				die_id = -ENODEV;
+			break;
+		}
+	}
+
+	return die_id;
+}
+
 /*
  * build pci bus to socket mapping
  */
@@ -1435,22 +1458,7 @@ static int snbep_pci2phy_map_init(int devid, int nodeid_loc, int idmap_loc, bool
 				break;
 			}
 
-			/*
-			 * every three bits in the Node ID mapping register maps
-			 * to a particular node.
-			 */
-			for (i = 0; i < 8; i++) {
-				if (nodeid == GIDNIDMAP(config, i)) {
-					if (topology_max_die_per_package() > 1)
-						die_id = i;
-					else
-						die_id = topology_phys_to_logical_pkg(i);
-					if (die_id < 0)
-						die_id = -ENODEV;
-					map->pbus_to_dieid[bus] = die_id;
-					break;
-				}
-			}
+			map->pbus_to_dieid[bus] = topology_gidnid_map(nodeid, config);
 			raw_spin_unlock(&pci2phy_map_lock);
 		} else {
 			segment = pci_domain_nr(ubox_dev->bus);
@@ -5596,7 +5604,7 @@ static int discover_upi_topology(struct intel_uncore_type *type, int ubox_did, i
 	struct pci_dev *ubox = NULL;
 	struct pci_dev *dev = NULL;
 	u32 nid, gid;
-	int i, idx, lgc_pkg, ret = -EPERM;
+	int idx, lgc_pkg, ret = -EPERM;
 	struct intel_uncore_topology *upi;
 	unsigned int devfn;
 
@@ -5611,27 +5619,22 @@ static int discover_upi_topology(struct intel_uncore_type *type, int ubox_did, i
 			break;
 		}
 
-		for (i = 0; i < 8; i++) {
-			if (nid != GIDNIDMAP(gid, i))
-				continue;
-			lgc_pkg = topology_phys_to_logical_pkg(i);
-			if (lgc_pkg < 0) {
-				ret = -EPERM;
-				goto err;
-			}
-			for (idx = 0; idx < type->num_boxes; idx++) {
-				upi = &type->topology[lgc_pkg][idx];
-				devfn = PCI_DEVFN(dev_link0 + idx, ICX_UPI_REGS_ADDR_FUNCTION);
-				dev = pci_get_domain_bus_and_slot(pci_domain_nr(ubox->bus),
-								  ubox->bus->number,
-								  devfn);
-				if (dev) {
-					ret = upi_fill_topology(dev, upi, idx);
-					if (ret)
-						goto err;
-				}
+		lgc_pkg = topology_gidnid_map(nid, gid);
+		if (lgc_pkg < 0) {
+			ret = -EPERM;
+			goto err;
+		}
+		for (idx = 0; idx < type->num_boxes; idx++) {
+			upi = &type->topology[lgc_pkg][idx];
+			devfn = PCI_DEVFN(dev_link0 + idx, ICX_UPI_REGS_ADDR_FUNCTION);
+			dev = pci_get_domain_bus_and_slot(pci_domain_nr(ubox->bus),
+							  ubox->bus->number,
+							  devfn);
+			if (dev) {
+				ret = upi_fill_topology(dev, upi, idx);
+				if (ret)
+					goto err;
 			}
-			break;
 		}
 	}
 err:

Re: [PATCH v2 0/2] Fix NULL pointer dereference issue during discovering UPI topology

[Liang, Kan]

On 2023-11-27 1:52 p.m., alexander.antonov@linux.intel.com wrote:
> From: Alexander Antonov <alexander.antonov@linux.intel.com>
> 
> The NULL dereference happens inside upi_fill_topology() procedure in
> case of disabling one of the sockets on the system.
> 
> For example, if you disable the 2nd socket on a 4-socket system then
> uncore_max_dies() returns 3 and inside pmu_alloc_topology() memory will
> be allocated only for 3 sockets and stored in type->topology.
> In discover_upi_topology() memory is accessed by socket id from CPUNODEID
> registers which contain physical ids (from 0 to 3) and on the line:
> 
>     upi = &type->topology[nid][idx];
> 
> out-of-bound access will happen and the 'upi' pointer will be passed to
> upi_fill_topology() where it will be dereferenced.
> 
> To avoid this issue update the code to convert physical socket id to
> logical socket id in discover_upi_topology() before accessing memory.
> 
> Changed in v2:
>  1. Factor out topology_gidnid_map() with common code for GIDNIDMAP procedure
> 
> Alexander Antonov (2):
>   perf/x86/intel/uncore: Fix NULL pointer dereference issue in
>     upi_fill_topology()
>   perf/x86/intel/uncore: Factor out topology_gidnid_map()

Reviewed-by: Kan Liang <kan.liang@linux.intel.com>

Thanks,
Kan

> 
>  arch/x86/events/intel/uncore_snbep.c | 71 ++++++++++++++++------------
>  1 file changed, 40 insertions(+), 31 deletions(-)
>