Patch "perf/x86/intel/uncore: Fix NULL pointer dereference issue in upi_fill_topology()" has been added to the 6.7-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

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

to the 6.7-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     perf-x86-intel-uncore-fix-null-pointer-dereference-i.patch
and it can be found in the queue-6.7 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit c96571ba3e24e1efd4465ecacca43f494b9eb0a8
Author: Alexander Antonov <alexander.antonov@xxxxxxxxxxxxxxx>
Date:   Mon Nov 27 10:52:45 2023 -0800

    perf/x86/intel/uncore: Fix NULL pointer dereference issue in upi_fill_topology()
    
    [ Upstream commit 1692cf434ba13ee212495b5af795b6a07e986ce4 ]
    
    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
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

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: