[PATCH] RDMA: Add missed netdev_put() for the netdevice_tracker

[Jason Gunthorpe <jgg@nvidia.com>]

The netdev core will detect if any untracked puts are done on tracked
pointers and throw refcount warnings:

  refcount_t: decrement hit 0; leaking memory.
  WARNING: CPU: 1 PID: 33 at lib/refcount.c:31 refcount_warn_saturate+0x1d7/0x1f0 lib/refcount.c:31
  Modules linked in:
  CPU: 1 PID: 33 Comm: kworker/u4:2 Not tainted 6.1.0-rc8-next-20221207-syzkaller #0
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
  Workqueue: ib-unreg-wq ib_unregister_work
  RIP: 0010:refcount_warn_saturate+0x1d7/0x1f0 lib/refcount.c:31
  Code: 05 5a 60 51 0a 01 e8 35 0a b5 05 0f 0b e9 d3 fe ff ff e8 6c 9b 75 fd 48 c7 c7 c0 6d a6 8a c6 05 37 60 51 0a 01 e8 16 0a b5 05 <0f> 0b e9 b4 fe
  +ff ff 48 89 ef e8 5a b5 c3 fd e9 5c fe ff ff 0f 1f
  RSP: 0018:ffffc90000aa7b30 EFLAGS: 00010082
  RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
  RDX: ffff8880172f9d40 RSI: ffffffff8166b1dc RDI: fffff52000154f58
  RBP: ffff88807906c600 R08: 0000000000000005 R09: 0000000000000000
  R10: 0000000080000001 R11: 0000000000000000 R12: 1ffff92000154f6b
  R13: 0000000000000000 R14: ffff88807906c600 R15: ffff888046894000
  FS:  0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007ffe350a8ff8 CR3: 000000007a9e7000 CR4: 00000000003526e0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
   <TASK>
   __refcount_dec include/linux/refcount.h:344 [inline]
   refcount_dec include/linux/refcount.h:359 [inline]
   ref_tracker_free+0x539/0x6b0 lib/ref_tracker.c:118
   netdev_tracker_free include/linux/netdevice.h:4039 [inline]
   netdev_put include/linux/netdevice.h:4056 [inline]
   dev_put include/linux/netdevice.h:4082 [inline]
   free_netdevs+0x1f8/0x470 drivers/infiniband/core/device.c:2204
   __ib_unregister_device+0xa0/0x1a0 drivers/infiniband/core/device.c:1478
   ib_unregister_work+0x19/0x30 drivers/infiniband/core/device.c:1586
   process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289
   worker_thread+0x669/0x1090 kernel/workqueue.c:2436
   kthread+0x2e8/0x3a0 kernel/kthread.c:376
   ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

So change the missed dev_put for pdata->netdev to also follow the tracker.

Fixes: 09f530f0c6d6 ("RDMA: Add netdevice_tracker to ib_device_set_netdev()")
Reported-by: syzbot+3fd8326d9a0812d19218@syzkaller.appspotmail.com
Reported-by: syzbot+a1ed8ffe3121380cd5dd@syzkaller.appspotmail.com
Reported-by: syzbot+8d0a099c8a6d1e4e601c@syzkaller.appspotmail.com
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
 drivers/infiniband/core/device.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index ff35cebb25e265..4d4f71f9728e13 100644
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -2201,7 +2201,7 @@ static void free_netdevs(struct ib_device *ib_dev)
 			 * comparisons after the put
 			 */
 			rcu_assign_pointer(pdata->netdev, NULL);
-			dev_put(ndev);
+			netdev_put(ndev, &pdata->netdev_tracker);
 		}
 		spin_unlock_irqrestore(&pdata->netdev_lock, flags);
 	}

base-commit: 682c0722addae4b4a1440c9db9d8c86cb8e09ce5
-- 
2.38.1