git: 81debbd60e57 - main - pfsync: fix use of invalidated stack variable
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Date: Mon, 25 Mar 2024 04:44:51 UTC
The branch main has been updated by kp: URL: https://cgit.FreeBSD.org/src/commit/?id=81debbd60e5773e812e9227a2003ea88699580be commit 81debbd60e5773e812e9227a2003ea88699580be Author: Kristof Provost <kp@FreeBSD.org> AuthorDate: 2024-03-24 08:46:31 +0000 Commit: Kristof Provost <kp@FreeBSD.org> CommitDate: 2024-03-25 04:44:24 +0000 pfsync: fix use of invalidated stack variable Calls to pfsync_send_plus() pass pointers to stack variables. If pfsync_sendout() then fails it retains the pointer to these stack variables, accesing them later. Allocate a buffer and copy the data instead, so that we can retain the pointer safely. Reported by: CI KASAN, markj MFC after: 1 week --- sys/netpfil/pf/if_pfsync.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/sys/netpfil/pf/if_pfsync.c b/sys/netpfil/pf/if_pfsync.c index e90bc60b85fa..6e43071e1d0d 100644 --- a/sys/netpfil/pf/if_pfsync.c +++ b/sys/netpfil/pf/if_pfsync.c @@ -474,6 +474,9 @@ pfsync_clone_destroy(struct ifnet *ifp) MPASS(TAILQ_EMPTY(&b->b_deferrals)); PFSYNC_BUCKET_UNLOCK(b); + free(b->b_plus, M_PFSYNC); + b->b_plus = NULL; + callout_drain(&b->b_tmo); } @@ -1766,6 +1769,7 @@ pfsync_drop(struct pfsync_softc *sc) } b->b_len = PFSYNC_MINPKT; + free(b->b_plus, M_PFSYNC); b->b_plus = NULL; } } @@ -1906,6 +1910,7 @@ pfsync_sendout(int schedswi, int c) bcopy(b->b_plus, m->m_data + offset, b->b_pluslen); offset += b->b_pluslen; + free(b->b_plus, M_PFSYNC); b->b_plus = NULL; } @@ -2563,13 +2568,21 @@ pfsync_send_plus(void *plus, size_t pluslen) PFSYNC_BUCKET_LOCK(b); + MPASS(b->b_plus == NULL); + if (b->b_len + pluslen > sc->sc_ifp->if_mtu) pfsync_sendout(1, b->b_id); - b->b_plus = plus; + b->b_plus = malloc(pluslen, M_PFSYNC, M_NOWAIT); + if (b->b_plus == NULL) + goto out; + + memcpy(b->b_plus, plus, pluslen); b->b_len += (b->b_pluslen = pluslen); pfsync_sendout(1, b->b_id); + +out: PFSYNC_BUCKET_UNLOCK(b); }