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IoVerifyVolume and VPB leak

Bill_ZissimopoulosBill_Zissimopoulos Member Posts: 118

In my testing it appears that IoVerifyVolume can leak the VPB of the passed device. This happens in either of these 2 cases:

  • The device has not been mounted before.
  • The device has been mounted before but the verification (IRP_MN_VERIFY_VOLUME) fails.

In either of these cases IoVerifyVolume attempts to (re-)mount the device. For this purpose it creates a new VPB using IopCreateVpb, but it does so without regard of whether a VPB exists already. IopCreateVpb appears to simply overwrite the DEVICE_OBJECT::Vpb field.

In my testing at least this appears to create a memory leak. Indeed if I modify my driver so that it frees that old VPB, the system chugs along without any complains about double frees or anything like that. (And yes, I always run my driver tests with verifier enabled).

This problem appears to exist in at least Win10 2004, but I believe it also exists in earlier and later versions of the OS.

Have I misunderstood IoVerifyVolume and how to use it?

Thank you.

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