DF-0747 / fix_run.log
=== FIXED MODULE TEST ===
kernel: DragonFly 6.5-DEVELOPMENT #0: Thu Jul 2 06:02:54 UTC 2026
module: SHA256 (/boot/kernel/ipfw3_layer4.ko) = aec57daea3003e1342c79e336fc0f7d7bdb3496620092f67da62c0d5ef66e001
net.filters_default_to_accept: 0 -> 1
4 2 0xffffffff82600000 49000 ipfw3.ko
5 2 0xffffffff82649000 95000 ipfw3_basic.ko
6 1 0xffffffff826de000 1000 ipfw3_layer4.ko
--- BEFORE counters ---
00100 2 140 allow tcp established
65534 0 0 allow
65535 0 0 allow
--- running trigger ---
=== DF-0747: check_established th_flags read on non-first TCP frag ===
Bug: ip_fw3_layer4.c:184 L3HDR(tcphdr,ip)->th_flags reads ip+33
on fragments that have no TCP header (pullup skipped at offset>0)
[Case 1] payload=24, th_flags_byte=TH_ACK(0x10) โ expect MATCH established
sent: offset=8 payload=24 flags_byte=0x10 (44 bytes)
[Case 2] payload=24, th_flags_byte=TH_SYN(0x02) โ expect NOT established
sent: offset=8 payload=24 flags_byte=0x02 (44 bytes)
[Case 3] min-size payload=8, th_flags read at ip+33 = 5-byte OOB
sent: offset=8 payload=8 flags_byte=0x00 (28 bytes)
[Case 4] payload=14, th_flags_byte=TH_ACK(0x10) โ MATCH established
sent: offset=8 payload=14 flags_byte=0x10 (34 bytes)
DONE. Check 'ipfw3 show' rule-hit counters:
rule 100 (allow established) should have Case 1 + Case 4 hits
rule 200 (deny) should have Case 2 hit
Case 3 hit either rule depending on stale backing-store bytes
--- AFTER counters ---
00100 18 1976 allow tcp established
65534 0 0 allow
65535 0 0 allow
=== disabling ipfw3 ===
net.inet.ip.fw3.enable: 1 -> 0