git: db4d2d7222ee - main - tcp: When rack or bbr get a pullup failure in the common code, don't free the NULL mbuf.

[Randall Stewart]

The branch main has been updated by rrs:

URL: https://cgit.FreeBSD.org/src/commit/?id=db4d2d7222ee1c03ade4eb3b82e263ce5c94cf61

commit db4d2d7222ee1c03ade4eb3b82e263ce5c94cf61
Author:     Randall Stewart <rrs at FreeBSD.org>
AuthorDate: 2021-07-16 17:59:57 +0000
Commit:     Randall Stewart <rrs at FreeBSD.org>
CommitDate: 2021-07-16 17:59:57 +0000

    tcp: When rack or bbr get a pullup failure in the common code, don't free the NULL mbuf.
    
    There is a bug in the error path where rack_bbr_common does a m_pullup() and the pullup fails.
    There is a stray mfree(m) after m is set to NULL. This is not a good idea :-)
    
    Reviewed by: tuexen
    Sponsored by: Netflix Inc.
    Differential Revision: https://reviews.freebsd.org/D31194
---
 sys/netinet/tcp_stacks/rack_bbr_common.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/sys/netinet/tcp_stacks/rack_bbr_common.c b/sys/netinet/tcp_stacks/rack_bbr_common.c
index d9f48f733e93..baa267b43752 100644
--- a/sys/netinet/tcp_stacks/rack_bbr_common.c
+++ b/sys/netinet/tcp_stacks/rack_bbr_common.c
@@ -210,7 +210,6 @@ ctf_get_enet_type(struct ifnet *ifp, struct mbuf *m)
 				m = m_pullup(m, sizeof(*ip6) + sizeof(*th));
 				if (m == NULL) {
 					KMOD_TCPSTAT_INC(tcps_rcvshort);
-					m_freem(m);
 					return (-1);
 				}
 			}
@@ -243,7 +242,6 @@ ctf_get_enet_type(struct ifnet *ifp, struct mbuf *m)
 				m = m_pullup(m, sizeof (struct tcpiphdr));
 				if (m == NULL) {
 					KMOD_TCPSTAT_INC(tcps_rcvshort);
-					m_freem(m);
 					return (-1);
 				}
 			}