| From 552e1abfec69281a1440d377638757df7c12a69d Mon Sep 17 00:00:00 2001 |
| From: Mohammed Gamal <mgamal@redhat.com> |
| Date: Tue, 14 Jan 2020 15:09:50 +0200 |
| Subject: [PATCH] hv_netvsc: Fix memory leak when removing rndis device |
| |
| commit 536dc5df2808efbefc5acee334d3c4f701790ec0 upstream. |
| |
| kmemleak detects the following memory leak when hot removing |
| a network device: |
| |
| unreferenced object 0xffff888083f63600 (size 256): |
| comm "kworker/0:1", pid 12, jiffies 4294831717 (age 1113.676s) |
| hex dump (first 32 bytes): |
| 00 40 c7 33 80 88 ff ff 00 00 00 00 10 00 00 00 .@.3............ |
| 00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N.......... |
| backtrace: |
| [<00000000d4a8f5be>] rndis_filter_device_add+0x117/0x11c0 [hv_netvsc] |
| [<000000009c02d75b>] netvsc_probe+0x5e7/0xbf0 [hv_netvsc] |
| [<00000000ddafce23>] vmbus_probe+0x74/0x170 [hv_vmbus] |
| [<00000000046e64f1>] really_probe+0x22f/0xb50 |
| [<000000005cc35eb7>] driver_probe_device+0x25e/0x370 |
| [<0000000043c642b2>] bus_for_each_drv+0x11f/0x1b0 |
| [<000000005e3d09f0>] __device_attach+0x1c6/0x2f0 |
| [<00000000a72c362f>] bus_probe_device+0x1a6/0x260 |
| [<0000000008478399>] device_add+0x10a3/0x18e0 |
| [<00000000cf07b48c>] vmbus_device_register+0xe7/0x1e0 [hv_vmbus] |
| [<00000000d46cf032>] vmbus_add_channel_work+0x8ab/0x1770 [hv_vmbus] |
| [<000000002c94bb64>] process_one_work+0x919/0x17d0 |
| [<0000000096de6781>] worker_thread+0x87/0xb40 |
| [<00000000fbe7397e>] kthread+0x333/0x3f0 |
| [<000000004f844269>] ret_from_fork+0x3a/0x50 |
| |
| rndis_filter_device_add() allocates an instance of struct rndis_device |
| which never gets deallocated as rndis_filter_device_remove() sets |
| net_device->extension which points to the rndis_device struct to NULL, |
| leaving the rndis_device dangling. |
| |
| Since net_device->extension is eventually freed in free_netvsc_device(), |
| we refrain from setting it to NULL inside rndis_filter_device_remove() |
| |
| Signed-off-by: Mohammed Gamal <mgamal@redhat.com> |
| Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| diff --git a/drivers/net/hyperv/rndis_filter.c b/drivers/net/hyperv/rndis_filter.c |
| index e32014841fa6..539d58bd1558 100644 |
| --- a/drivers/net/hyperv/rndis_filter.c |
| +++ b/drivers/net/hyperv/rndis_filter.c |
| @@ -1435,8 +1435,6 @@ void rndis_filter_device_remove(struct hv_device *dev, |
| /* Halt and release the rndis device */ |
| rndis_filter_halt_device(net_dev, rndis_dev); |
| |
| - net_dev->extension = NULL; |
| - |
| netvsc_device_remove(dev); |
| } |
| |
| -- |
| 2.7.4 |
| |
