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authorAndrey V. Elsukov <ae@FreeBSD.org>2018-11-27 09:04:06 +0000
committerAndrey V. Elsukov <ae@FreeBSD.org>2018-11-27 09:04:06 +0000
commita716ad4a35627bfe68d6681e1a4bb0c1e922325d (patch)
tree9c17cc7f296353ee8b12b6006b194b8272f8ab6a /sys/net/if.c
parent71cf0a4e290b4cabf4b89b9b46caefed3d1b29fa (diff)
downloadsrc-a716ad4a35627bfe68d6681e1a4bb0c1e922325d.tar.gz
src-a716ad4a35627bfe68d6681e1a4bb0c1e922325d.zip
Fix possible panic during ifnet detach in rtsock.
The panic can happen, when some application does dump of routing table using sysctl interface. To prevent this, set IFF_DYING flag in if_detach_internal() function, when ifnet under lock is removed from the chain. In sysctl_rtsock() take IFNET_RLOCK_NOSLEEP() to prevent ifnet detach during routes enumeration. In case, if some interface was detached in the time before we take the lock, add the check, that ifnet is not DYING. This prevents access to memory that could be freed after ifnet is unlinked. PR: 227720, 230498, 233306 Reviewed by: bz, eugen MFC after: 1 week Sponsored by: Yandex LLC Differential Revision: https://reviews.freebsd.org/D18338
Notes
Notes: svn path=/head/; revision=341008
Diffstat (limited to 'sys/net/if.c')
-rw-r--r--sys/net/if.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/sys/net/if.c b/sys/net/if.c
index 15b4d7c12d1e..98e313f1508f 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -1068,6 +1068,8 @@ if_detach_internal(struct ifnet *ifp, int vmove, struct if_clone **ifcp)
CK_STAILQ_FOREACH(iter, &V_ifnet, if_link)
if (iter == ifp) {
CK_STAILQ_REMOVE(&V_ifnet, ifp, ifnet, if_link);
+ if (!vmove)
+ ifp->if_flags |= IFF_DYING;
found = 1;
break;
}