diff options
| author | Kristof Provost <kp@FreeBSD.org> | 2025-10-02 14:48:22 +0000 |
|---|---|---|
| committer | Kristof Provost <kp@FreeBSD.org> | 2025-10-02 19:17:00 +0000 |
| commit | dd2fc08d85431e10ad60e01e97b98e9dc23322bd (patch) | |
| tree | 527f7dbade7f199233954af011079333279b9f3f | |
| parent | eee36ffa0d874f1c8aca912f7c2a8eba34509927 (diff) | |
pf: fix possibe SCTP panic
While processing SCTP packets we can enqueue work for later, in the
sctp_multihome_jobs queue. This deferred job includes a copy of the current
struct pf_pdesc, which must contain a valid pcksum pointer (in case of NAT).
However, jobs could be enqueued before we'd actually set this pointer in
pf_setup_pdesc(). Set this pointer before we scan the SCTP chunk headers (and
could enqueue deferred jobs.)
While here sprinkle in a few more assertions to ensure we got this right.
Reported-by: syzbot+974d0fb7e53c9aa31b90@syzkaller.appspotmail.com
MFC after: 3 days
Sponsored by: Rubicon Communications, LLC ("Netgate")
| -rw-r--r-- | sys/netpfil/pf/pf.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/sys/netpfil/pf/pf.c b/sys/netpfil/pf/pf.c index 2c6d62078e6a..25ae1193bfff 100644 --- a/sys/netpfil/pf/pf.c +++ b/sys/netpfil/pf/pf.c @@ -3364,7 +3364,7 @@ pf_change_ap(struct pf_pdesc *pd, struct pf_addr *a, u_int16_t *p, u_int16_t po; uint8_t u = pd->virtual_proto == IPPROTO_UDP; - MPASS(pd->pcksum); + MPASS(pd->pcksum != NULL); if (pd->af == AF_INET) { MPASS(pd->ip_sum); } @@ -7634,6 +7634,7 @@ again: nj->pd.m = j->pd.m; nj->op = j->op; + MPASS(nj->pd.pcksum); TAILQ_INSERT_TAIL(&pd->sctp_multihome_jobs, nj, next); } PF_SCTP_ENDPOINTS_UNLOCK(); @@ -7753,6 +7754,7 @@ pf_multihome_scan(int start, int len, struct pf_pdesc *pd, int op) job->pd.m = pd->m; job->op = op; + MPASS(job->pd.pcksum); TAILQ_INSERT_TAIL(&pd->sctp_multihome_jobs, job, next); break; } @@ -7786,6 +7788,7 @@ pf_multihome_scan(int start, int len, struct pf_pdesc *pd, int op) job->pd.m = pd->m; job->op = op; + MPASS(job->pd.pcksum); TAILQ_INSERT_TAIL(&pd->sctp_multihome_jobs, job, next); break; } @@ -10634,17 +10637,21 @@ pf_setup_pdesc(sa_family_t af, int dir, struct pf_pdesc *pd, struct mbuf **m0, REASON_SET(reason, PFRES_SHORT); return (-1); } - if (pf_scan_sctp(pd) != PF_PASS) { - *action = PF_DROP; - REASON_SET(reason, PFRES_SHORT); - return (-1); - } + /* * Placeholder. The SCTP checksum is 32-bits, but * pf_test_state() expects to update a 16-bit checksum. * Provide a dummy value which we'll subsequently ignore. + * Do this before pf_scan_sctp() so any jobs we enqueue + * have a pcksum set. */ pd->pcksum = &pd->sctp_dummy_sum; + + if (pf_scan_sctp(pd) != PF_PASS) { + *action = PF_DROP; + REASON_SET(reason, PFRES_SHORT); + return (-1); + } break; } case IPPROTO_ICMP: { |