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

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

[Anders Roxell]

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@linaro.org>
---
 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

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

[Hannes Reinecke]

On 7/4/25 14:55, Anders Roxell wrote:
> 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@linaro.org>
> ---
>   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);

Errm.
The description doesn't match the patch.
Care to fix it up?

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                  Kernel Storage Architect
hare@suse.de                                +49 911 74053 688
SUSE Software Solutions GmbH, Frankenstr. 146, 90461 Nürnberg
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