2023-11-27 18:53:16

by Alexander Antonov

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

From: Alexander Antonov <[email protected]>

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


2023-11-27 18:53:18

by Alexander Antonov

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

From: Alexander Antonov <[email protected]>

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 <[email protected]>
Tested-by: Kyle Meyer <[email protected]>
Signed-off-by: Alexander Antonov <[email protected]>
---
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

2023-11-27 18:53:20

by Alexander Antonov

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

From: Alexander Antonov <[email protected]>

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 <[email protected]>
---
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

2023-11-27 21:09:58

by Liang, Kan

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



On 2023-11-27 1:52 p.m., [email protected] wrote:
> From: Alexander Antonov <[email protected]>
>
> 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 <[email protected]>

Thanks,
Kan

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

2023-11-30 13:36:58

by tip-bot2 for Jacob Pan

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

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 <[email protected]>
AuthorDate: Mon, 27 Nov 2023 10:52:46 -08:00
Committer: Peter Zijlstra <[email protected]>
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 <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Kan Liang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
---
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:

2023-11-30 13:37:01

by tip-bot2 for Jacob Pan

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

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 <[email protected]>
AuthorDate: Mon, 27 Nov 2023 10:52:45 -08:00
Committer: Peter Zijlstra <[email protected]>
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 <[email protected]>
Signed-off-by: Alexander Antonov <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Kan Liang <[email protected]>
Tested-by: Kyle Meyer <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
---
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: