linux_dsm_epyc7002/net/core
Lorenz Bauer 85b8ac01a4 bpf, sockmap: Check update requirements after locking
It's currently possible to insert sockets in unexpected states into
a sockmap, due to a TOCTTOU when updating the map from a syscall.
sock_map_update_elem checks that sk->sk_state == TCP_ESTABLISHED,
locks the socket and then calls sock_map_update_common. At this
point, the socket may have transitioned into another state, and
the earlier assumptions don't hold anymore. Crucially, it's
conceivable (though very unlikely) that a socket has become unhashed.
This breaks the sockmap's assumption that it will get a callback
via sk->sk_prot->unhash.

Fix this by checking the (fixed) sk_type and sk_protocol without the
lock, followed by a locked check of sk_state.

Unfortunately it's not possible to push the check down into
sock_(map|hash)_update_common, since BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB
run before the socket has transitioned from TCP_SYN_RECV into
TCP_ESTABLISHED.

Fixes: 604326b41a ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/20200207103713.28175-1-lmb@cloudflare.com
2020-02-07 22:28:04 +01:00
..
bpf_sk_storage.c
datagram.c
datagram.h
dev_addr_lists.c
dev_ioctl.c net: Introduce peer to peer one step PTP time stamping. 2019-12-25 19:51:34 -08:00
dev.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2020-01-28 16:02:33 -08:00
devlink.c devlink: Add health recover notifications on devlink flows 2020-01-25 10:34:42 +01:00
drop_monitor.c
dst_cache.c
dst.c
failover.c
fib_notifier.c
fib_rules.c
filter.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2020-01-23 08:10:16 +01:00
flow_dissector.c flow_dissector: Fix to use new variables for port ranges in bpf hook 2020-01-27 11:25:07 +01:00
flow_offload.c
gen_estimator.c
gen_stats.c
gro_cells.c
hwbm.c
link_watch.c
lwt_bpf.c
lwtunnel.c
Makefile
neighbour.c neigh_stat_seq_next() should increase position index 2020-01-24 11:42:18 +01:00
net_namespace.c netns: Constify exported functions 2020-01-17 13:25:24 +01:00
net-procfs.c
net-sysfs.c
net-sysfs.h
net-traces.c
netclassid_cgroup.c
netevent.c
netpoll.c
netprio_cgroup.c
page_pool.c page_pool: help compiler remove code in case CONFIG_NUMA=n 2020-01-02 15:37:52 -08:00
pktgen.c Revert "pktgen: Allow configuration of IPv6 source address range" 2020-01-27 13:49:33 +01:00
ptp_classifier.c
request_sock.c
rtnetlink.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-01-26 10:40:21 +01:00
scm.c
secure_seq.c
skbuff.c net: Support GRO/GSO fraglist chaining. 2020-01-27 11:00:21 +01:00
skmsg.c net, sk_msg: Don't check if sock is locked when tearing down psock 2020-01-22 20:30:20 +01:00
sock_diag.c
sock_map.c bpf, sockmap: Check update requirements after locking 2020-02-07 22:28:04 +01:00
sock_reuseport.c soreuseport: Cleanup duplicate initialization of more_reuse->max_socks. 2020-01-27 11:01:16 +01:00
sock.c xsk, net: Make sock_def_readable() have external linkage 2020-01-22 00:08:52 +01:00
stream.c
sysctl_net_core.c net, sysctl: Fix compiler warning when only cBPF is present 2019-12-19 17:17:51 +01:00
timestamping.c net: Introduce a new MII time stamping interface. 2019-12-25 19:51:33 -08:00
tso.c
utils.c net: Fix skb->csum update in inet_proto_csum_replace16(). 2020-01-24 20:54:30 +01:00
xdp.c