The branch main has been updated by emaste: URL: https://cgit.FreeBSD.org/src/commit/?id=b16c731b0191d6c47de46a3c6057b0c5ec0dd420
commit b16c731b0191d6c47de46a3c6057b0c5ec0dd420 Author: Ed Maste <[email protected]> AuthorDate: 2026-06-05 21:00:07 +0000 Commit: Ed Maste <[email protected]> CommitDate: 2026-06-08 20:47:24 +0000 ipfw nat: Add assertion that mbuf is not a chain Discarding m_free's return value will result in an mbuf leak if the mbuf was in a chain. In general we should use m_freem if the mbuf may be in a chain, or assert that the return was NULL. There will not be a chain here due to m_megapullup, so add an assert. Reviewed by: ae Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D57479 --- sys/netpfil/ipfw/ip_fw_nat.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/sys/netpfil/ipfw/ip_fw_nat.c b/sys/netpfil/ipfw/ip_fw_nat.c index e816c7bd95eb..6ebde03fe2e3 100644 --- a/sys/netpfil/ipfw/ip_fw_nat.c +++ b/sys/netpfil/ipfw/ip_fw_nat.c @@ -291,7 +291,7 @@ free_nat_instance(struct cfg_nat *ptr) static int ipfw_nat(struct ip_fw_args *args, struct cfg_nat *t, struct mbuf *m) { - struct mbuf *mcl; + struct mbuf *mcl, *mfree __diagused; struct ip *ip; /* XXX - libalias duct tape */ int ldt, retval, found; @@ -396,7 +396,8 @@ ipfw_nat(struct ip_fw_args *args, struct cfg_nat *t, struct mbuf *m) (retval == PKT_ALIAS_IGNORED && (t->mode & PKT_ALIAS_DENY_INCOMING) != 0)))) { /* XXX - should i add some logging? */ - m_free(mcl); + mfree = m_free(mcl); + MPASS(mfree == NULL); args->m = NULL; return (IP_FW_DENY); }
