c8ac377464
1) We send out a normal sized packet with TSO on to start off. 2) ICMP is received indicating a smaller MTU. 3) We send the current sk_send_head which needs to be fragmented since it was created before the ICMP event. The first fragment is then sent out. At this point the remaining fragment is allocated by tcp_fragment. However, its size is padded to fit the L1 cache-line size therefore creating tail-room up to 124 bytes long. This fragment will also be sitting at sk_send_head. 4) tcp_sendmsg is called again and it stores data in the tail-room of of the fragment. 5) tcp_push_one is called by tcp_sendmsg which then calls tso_fragment since the packet as a whole exceeds the MTU. At this point we have a packet that has data in the head area being fed to tso_fragment which bombs out. My take on this is that we shouldn't ever call tcp_fragment on a TSO socket for a packet that is yet to be transmitted since this creates a packet on sk_send_head that cannot be extended. So here is a patch to change it so that tso_fragment is always used in this case. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net> |
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|---|---|---|
| .. | ||
| ipvs | ||
| netfilter | ||
| Kconfig | ||
| Makefile | ||
| af_inet.c | ||
| ah4.c | ||
| arp.c | ||
| datagram.c | ||
| devinet.c | ||
| esp4.c | ||
| fib_frontend.c | ||
| fib_hash.c | ||
| fib_lookup.h | ||
| fib_rules.c | ||
| fib_semantics.c | ||
| fib_trie.c | ||
| icmp.c | ||
| igmp.c | ||
| inetpeer.c | ||
| ip_forward.c | ||
| ip_fragment.c | ||
| ip_gre.c | ||
| ip_input.c | ||
| ip_options.c | ||
| ip_output.c | ||
| ip_sockglue.c | ||
| ipcomp.c | ||
| ipconfig.c | ||
| ipip.c | ||
| ipmr.c | ||
| multipath.c | ||
| multipath_drr.c | ||
| multipath_random.c | ||
| multipath_rr.c | ||
| multipath_wrandom.c | ||
| proc.c | ||
| protocol.c | ||
| raw.c | ||
| route.c | ||
| syncookies.c | ||
| sysctl_net_ipv4.c | ||
| tcp.c | ||
| tcp_bic.c | ||
| tcp_cong.c | ||
| tcp_diag.c | ||
| tcp_highspeed.c | ||
| tcp_htcp.c | ||
| tcp_hybla.c | ||
| tcp_input.c | ||
| tcp_ipv4.c | ||
| tcp_minisocks.c | ||
| tcp_output.c | ||
| tcp_scalable.c | ||
| tcp_timer.c | ||
| tcp_vegas.c | ||
| tcp_westwood.c | ||
| udp.c | ||
| xfrm4_input.c | ||
| xfrm4_output.c | ||
| xfrm4_policy.c | ||
| xfrm4_state.c | ||
| xfrm4_tunnel.c | ||