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| author | Adrian Chadd <adrian@FreeBSD.org> | 2015-09-07 23:16:39 +0000 |
|---|---|---|
| committer | Adrian Chadd <adrian@FreeBSD.org> | 2015-09-07 23:16:39 +0000 |
| commit | 15b1492c9b09c465f5e13deb85292c0f2173c7fc (patch) | |
| tree | 65d41346c0e215d91f84621d49ee3f0c3f0bc4fc /sys/dev/netmap | |
| parent | c80b6ca937d436f3acc02784343964400fc7deff (diff) | |
| download | src-15b1492c9b09c465f5e13deb85292c0f2173c7fc.tar.gz src-15b1492c9b09c465f5e13deb85292c0f2173c7fc.zip | |
Don't call enable_all_rings if the adapter has been freed.
This is a subtle use-after-free race that results in some very undesirable
hang behaviour.
Reviewed by: pkelsey
Obtained from: Kip Macy, NextBSD (https://github.com/NextBSD/NextBSD/commit/91a9bd1dbb33dafb41684d054e59d73976de9654)
Notes
Notes:
svn path=/head/; revision=287543
Diffstat (limited to 'sys/dev/netmap')
| -rw-r--r-- | sys/dev/netmap/netmap.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/sys/dev/netmap/netmap.c b/sys/dev/netmap/netmap.c index 8094fe35256c..56bbf120caff 100644 --- a/sys/dev/netmap/netmap.c +++ b/sys/dev/netmap/netmap.c @@ -2841,10 +2841,12 @@ void netmap_detach(struct ifnet *ifp) { struct netmap_adapter *na = NA(ifp); + int skip; if (!na) return; + skip = 0; NMG_LOCK(); netmap_disable_all_rings(ifp); na->ifp = NULL; @@ -2856,10 +2858,11 @@ netmap_detach(struct ifnet *ifp) * the driver is gone. */ if (na->na_flags & NAF_NATIVE) { - netmap_adapter_put(na); + skip = netmap_adapter_put(na); } /* give them a chance to notice */ - netmap_enable_all_rings(ifp); + if (skip == 0) + netmap_enable_all_rings(ifp); NMG_UNLOCK(); } |