From a0d571cbef41c091cbde482bb9b07e7a9e39f60b Mon Sep 17 00:00:00 2001 From: Kristof Provost Date: Fri, 18 Oct 2019 03:36:26 +0000 Subject: [PATCH] pf: Must be in NET_EPOCH to call icmp_error icmp_reflect(), called through icmp_error() requires us to be in NET_EPOCH. Failure to hold it leads to the following panic (with INVARIANTS): panic: Assertion in_epoch(net_epoch_preempt) failed at /usr/src/sys/netinet/ip_icmp.c:742 cpuid = 2 time = 1571233273 KDB: stack backtrace: db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe00e0977920 vpanic() at vpanic+0x17e/frame 0xfffffe00e0977980 panic() at panic+0x43/frame 0xfffffe00e09779e0 icmp_reflect() at icmp_reflect+0x625/frame 0xfffffe00e0977aa0 icmp_error() at icmp_error+0x720/frame 0xfffffe00e0977b10 pf_intr() at pf_intr+0xd5/frame 0xfffffe00e0977b50 ithread_loop() at ithread_loop+0x1c6/frame 0xfffffe00e0977bb0 fork_exit() at fork_exit+0x80/frame 0xfffffe00e0977bf0 fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe00e0977bf0 Note that we now enter NET_EPOCH twice if we enter ip_output() from pf_intr(), but ip_output() will soon be converted to a function that requires epoch, so entering NET_EPOCH directly from pf_intr() makes more sense. Discussed with: glebius@ --- sys/netpfil/pf/pf.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/sys/netpfil/pf/pf.c b/sys/netpfil/pf/pf.c index 2e83fdef8e87..b0b237af6e6c 100644 --- a/sys/netpfil/pf/pf.c +++ b/sys/netpfil/pf/pf.c @@ -1428,6 +1428,7 @@ pf_send(struct pf_send_entry *pfse) void pf_intr(void *v) { + struct epoch_tracker et; struct pf_send_head queue; struct pf_send_entry *pfse, *next; @@ -1438,6 +1439,8 @@ pf_intr(void *v) STAILQ_INIT(&V_pf_sendqueue); PF_SENDQ_UNLOCK(); + NET_EPOCH_ENTER(et); + STAILQ_FOREACH_SAFE(pfse, &queue, pfse_next, next) { switch (pfse->pfse_type) { #ifdef INET @@ -1464,6 +1467,7 @@ pf_intr(void *v) } free(pfse, M_PFTEMP); } + NET_EPOCH_EXIT(et); CURVNET_RESTORE(); }