From f1db666a6190e43d8e98c8aae807a9a85538d84b Mon Sep 17 00:00:00 2001 From: "Bjoern A. Zeeb" Date: Fri, 28 Feb 2020 11:16:41 +0000 Subject: mld6: initialize oifp to avoid bogus results/panics in edge cases In certain cases (probably not during normal operation but observed in the lab during development) ip6_ouput() could return without error and ifpp (&oifp) not updated. Given oifp was never initialized we would take the later branch as oifp was not NULL, and when calling icmp6_ifstat_inc() we would panic dereferencing a garbage pointer. For code stability initialize oifp to NULL before first use to always have a deterministic value and not rely on a called function to behave and always and for ever do the work for us as we hope for. MFC after: 3 days Sponsored by: Netflix --- sys/netinet6/mld6.c | 1 + 1 file changed, 1 insertion(+) (limited to 'sys/netinet6/mld6.c') diff --git a/sys/netinet6/mld6.c b/sys/netinet6/mld6.c index 5eb577379c6b..ccfa499739f0 100644 --- a/sys/netinet6/mld6.c +++ b/sys/netinet6/mld6.c @@ -3159,6 +3159,7 @@ mld_dispatch_packet(struct mbuf *m) mld = (struct mld_hdr *)(mtod(md, uint8_t *) + off); type = mld->mld_type; + oifp = NULL; error = ip6_output(m0, &mld_po, NULL, IPV6_UNSPECSRC, &im6o, &oifp, NULL); if (error) { -- cgit v1.2.3