From 5e98cae661f3a7e85df7f277660765b823454073 Mon Sep 17 00:00:00 2001 From: Kristof Provost Date: Mon, 12 Apr 2021 11:45:48 +0200 Subject: [PATCH] pf: Ensure that we don't use kif passed to pfi_kkif_attach() Once a kif is passed to pfi_kkif_attach() we must ensure we never re-use it for anything else. Set the kif to NULL afterwards to guarantee this. Reported-by: syzbot+be5d4f4a7a4c295e659a@syzkaller.appspotmail.com MFC after: 4 weeks Sponsored by: Rubicon Communications, LLC ("Netgate") --- sys/netpfil/pf/pf_if.c | 1 + sys/netpfil/pf/pf_ioctl.c | 3 +++ 2 files changed, 4 insertions(+) diff --git a/sys/netpfil/pf/pf_if.c b/sys/netpfil/pf/pf_if.c index be290a1e1f2e..4630098221c8 100644 --- a/sys/netpfil/pf/pf_if.c +++ b/sys/netpfil/pf/pf_if.c @@ -486,6 +486,7 @@ pfi_dynaddr_setup(struct pf_addr_wrap *aw, sa_family_t af) dyn->pfid_kif = pfi_kkif_attach(kif, IFG_ALL); else dyn->pfid_kif = pfi_kkif_attach(kif, aw->v.ifname); + kif = NULL; pfi_kkif_ref(dyn->pfid_kif); dyn->pfid_net = pfi_unmask(&aw->v.a.mask); diff --git a/sys/netpfil/pf/pf_ioctl.c b/sys/netpfil/pf/pf_ioctl.c index 0b8570f294bf..6ea2a1c4571c 100644 --- a/sys/netpfil/pf/pf_ioctl.c +++ b/sys/netpfil/pf/pf_ioctl.c @@ -2345,6 +2345,7 @@ pf_ioctl_addrule(struct pf_krule *rule, uint32_t ticket, rule->nr = 0; if (rule->ifname[0]) { rule->kif = pfi_kkif_attach(kif, rule->ifname); + kif = NULL; pfi_kkif_ref(rule->kif); } else rule->kif = NULL; @@ -2962,6 +2963,7 @@ pfioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, struct thread *td if (newrule->ifname[0]) { newrule->kif = pfi_kkif_attach(kif, newrule->ifname); + kif = NULL; pfi_kkif_ref(newrule->kif); } else newrule->kif = NULL; @@ -3747,6 +3749,7 @@ pfioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, struct thread *td } if (pa->ifname[0]) { pa->kif = pfi_kkif_attach(kif, pa->ifname); + kif = NULL; pfi_kkif_ref(pa->kif); } else pa->kif = NULL;