Change Details

Fix potential crash in the ng_nat module when attaching directly to the layer 2 (ethernet) while calculating TCP checksum. The issue is due to in_delayed_cksum() expecting to access IP header at the offset 0 from the mbuf start, while if we are attached to the L2 directly, the IP header at going to be at the certain offset. Provide a specialized version of the in_delayed_cksum() kernel API to DTRT in such case.

Fix potential crash in the ng_nat module when attaching directly to the layer 2 (ethernet) while calculating TCP checksum. The issue is due to in_delayed_cksum() expecting to access IP header at the offset 0 from the mbuf start, while if we are attached to the L2 directly, the IP header at going to be at the certain offset. As a result, in_delayed_cksum() will read some bogus value and try to use it as ip_len, obviously screwing up the calculation but also potentially causing assertion panic trying to read past allocated mbuf boundary. Provide a specialized version of the in_delayed_cksum() kernel API to DTRT in such case.

Fix potential crash in the ng_nat module when attaching directly to the layer 2 (ethernet) while calculating TCP checksum. The issue is due to in_delayed_cksum() expecting to access IP header at the offset 0 from the mbuf start, while if we are attached to the L2 directly, the IP header at going to be at the certain offset. As a result, in_delayed_cksum() will read some bogus value and try to use it as ip_len, obviously screwing up the calculation but also potentially causing assertion panic trying to read past allocated mbuf boundary. Provide a specialized version of the in_delayed_cksum() kernel API to DTRT in such case.