icmp: don't step on recycled socket descriptors
This change fixes lazy socket descriptor handling in ListenPacket to
avoid treading on someone's socket descriptors which are recycled by
descriptor duplication. The issue happens when calling ListenPacket for
non-privileged ICMP endpoint concurrently.
Fixes golang/go#16969.
Change-Id: I4d7672535f5aeb2a0b71f8af2c7ba271a085f418
Reviewed-on: https://go-review.googlesource.com/28473
Run-TryBot: Mikio Hara <mikioh.mikioh@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2 files changed
