[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@xxxxxxxxxxxxxxx>
AuthorDate:    Mon, 27 Nov 2023 10:52:45 -08:00
Committer:     Peter Zijlstra <peterz@xxxxxxxxxxxxx>
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@xxxxxxx>
Signed-off-by: Alexander Antonov <alexander.antonov@xxxxxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Reviewed-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Tested-by: Kyle Meyer <kyle.meyer@xxxxxxx>
Link: https://lore.kernel.org/r/20231127185246.2371939-2-alexander.antonov@xxxxxxxxxxxxxxx
---
 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: