[tip: perf/core] perf/x86/intel/uncore: Fix reference count leak in sad_cfg_iio_topology()

[tip-bot2 for Xiongfeng Wang]

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

Commit-ID:     c508eb042d9739bf9473526f53303721b70e9100
Gitweb:        https://git.kernel.org/tip/c508eb042d9739bf9473526f53303721b70e9100
Author:        Xiongfeng Wang <wangxiongfeng2@xxxxxxxxxx>
AuthorDate:    Fri, 18 Nov 2022 14:31:34 +08:00
Committer:     Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Thu, 24 Nov 2022 11:09:24 +01:00

perf/x86/intel/uncore: Fix reference count leak in sad_cfg_iio_topology()

pci_get_device() will increase the reference count for the returned
pci_dev, and also decrease the reference count for the input parameter
*from* if it is not NULL.

If we break the loop in sad_cfg_iio_topology() with 'dev' not NULL. We
need to call pci_dev_put() to decrease the reference count. Since
pci_dev_put() can handle the NULL input parameter, we can just add one
pci_dev_put() right before 'return ret'.

Fixes: c1777be3646b ("perf/x86/intel/uncore: Enable I/O stacks to IIO PMON mapping on SNR")
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Reviewed-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20221118063137.121512-2-wangxiongfeng2@xxxxxxxxxx
---
 arch/x86/events/intel/uncore_snbep.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/events/intel/uncore_snbep.c b/arch/x86/events/intel/uncore_snbep.c
index b8f9bd1..b14d591 100644
--- a/arch/x86/events/intel/uncore_snbep.c
+++ b/arch/x86/events/intel/uncore_snbep.c
@@ -4743,6 +4743,8 @@ static int sad_cfg_iio_topology(struct intel_uncore_type *type, u8 *sad_pmon_map
 		type->topology[die][stack_id].iio->pci_bus_no = dev->bus->number;
 	}
 
+	pci_dev_put(dev);
+
 	return ret;
 }