I looked at the illumos kernel sources, and I proved that this happened using dtrace.
It is a strange case, but the actual strange errno will only come from the network stack as far as I can tell.
For solaris users pushing high amounts of SMB2 traffic. This is a fairly important fix, the way the error manifests can be VERY hard to track down, and will show up as samba just being unreliable. (Randomly closing connections.)
Created attachment 8635 [details]
patch for 4.0
Created attachment 8636 [details]
patch for 3.6
This is fixed in current releases