svn commit: r339339 - head/sys/netinet

[Bjoern A. Zeeb]

Author: bz
Date: Fri Oct 12 22:51:45 2018
New Revision: 339339
URL: https://svnweb.freebsd.org/changeset/base/339339

Log:
  In udp_input() when walking the pcblist we can come across
  an inp marked FREED after the epoch(9) changes.
  Check once we hold the lock and skip the inp if it is the case.
  
  Contrary to IPv6 the locking of the inp is outside the multicast
  section and hence a single check seems to suffice.
  
  PR:		232192
  Reviewed by:	mmacy, markj
  Approved by:	re (kib)
  Differential Revision:	https://reviews.freebsd.org/D17540

Modified:
  head/sys/netinet/udp_usrreq.c

Modified: head/sys/netinet/udp_usrreq.c
==============================================================================
--- head/sys/netinet/udp_usrreq.c	Fri Oct 12 22:40:54 2018	(r339338)
+++ head/sys/netinet/udp_usrreq.c	Fri Oct 12 22:51:45 2018	(r339339)
@@ -551,6 +551,11 @@ udp_input(struct mbuf **mp, int *offp, int proto)
 
 			INP_RLOCK(inp);
 
+			if (__predict_false(inp->inp_flags2 & INP_FREED)) {
+				INP_RUNLOCK(inp);
+				continue;
+			}
+
 			/*
 			 * XXXRW: Because we weren't holding either the inpcb
 			 * or the hash lock when we checked for a match