[PATCH] pps: Fix IDR memory leak in module exit

From: Anders Roxell
Date: Fri Jul 04 2025 - 08:56:06 EST


Add missing idr_destroy() call in pps_exit() to properly free the pps_idr
radix tree nodes. Without this, module load/unload cycles leak 576-byte
radix tree node allocations, detectable by kmemleak as:

unreferenced object (size 576):
backtrace:
[<ffffffff81234567>] radix_tree_node_alloc+0xa0/0xf0
[<ffffffff81234568>] idr_get_free+0x128/0x280

The pps_idr is initialized via DEFINE_IDR() at line 32 and used throughout
the PPS subsystem for device ID management. The fix follows the documented
pattern in lib/idr.c and matches the cleanup approach used by other drivers
such as drivers/uio/uio.c.

This leak was discovered through comprehensive module testing with cumulative
kmemleak detection across 10 load/unload iterations per module.

Fixes: eae9d2ba0cfc ("LinuxPPS: core support")
Signed-off-by: Anders Roxell <anders.roxell@xxxxxxxxxx>
---
drivers/scsi/scsi_transport_iscsi.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index c75a806496d6..adbedb58930d 100644
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -5024,6 +5024,7 @@ static void __exit iscsi_transport_exit(void)
class_unregister(&iscsi_endpoint_class);
class_unregister(&iscsi_iface_class);
class_unregister(&iscsi_transport_class);
+ idr_destroy(&iscsi_ep_idr);
}

module_init(iscsi_transport_init);
--
2.47.2