linux/net/core
Martin KaFai Lau 061ff04071 bpf: tcp: Stop bpf_setsockopt(TCP_CONGESTION) in init ops to recur itself
When a bad bpf prog '.init' calls
bpf_setsockopt(TCP_CONGESTION, "itself"), it will trigger this loop:

.init => bpf_setsockopt(tcp_cc) => .init => bpf_setsockopt(tcp_cc) ...
... => .init => bpf_setsockopt(tcp_cc).

It was prevented by the prog->active counter before but the prog->active
detection cannot be used in struct_ops as explained in the earlier
patch of the set.

In this patch, the second bpf_setsockopt(tcp_cc) is not allowed
in order to break the loop.  This is done by using a bit of
an existing 1 byte hole in tcp_sock to check if there is
on-going bpf_setsockopt(TCP_CONGESTION) in this tcp_sock.

Note that this essentially limits only the first '.init' can
call bpf_setsockopt(TCP_CONGESTION) to pick a fallback cc (eg. peer
does not support ECN) and the second '.init' cannot fallback to
another cc.  This applies even the second
bpf_setsockopt(TCP_CONGESTION) will not cause a loop.

Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20220929070407.965581-5-martin.lau@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-09-29 09:25:47 -07:00
..
.gitignore net: skb: use auto-generation to convert skb drop reason to string 2022-06-07 12:51:41 +02:00
bpf_sk_storage.c net: Fix data-races around sysctl_optmem_max. 2022-08-24 13:46:57 +01:00
datagram.c iov_iter: advancing variants of iov_iter_get_pages{,_alloc}() 2022-08-08 22:37:22 -04:00
dev_addr_lists_test.c net: kunit: add a test for dev_addr_lists 2021-11-20 12:25:57 +00:00
dev_addr_lists.c net: extract a few internals from netdevice.h 2022-04-07 20:32:09 -07:00
dev_ioctl.c net: rename reference+tracking helpers 2022-06-09 21:52:55 -07:00
dev.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-08-25 16:07:42 -07:00
dev.h net: add skb_defer_max sysctl 2022-05-16 11:33:59 +01:00
devlink.c Revert "net: devlink: add RNLT lock assertion to devlink_compat_switch_id_get()" 2022-08-30 23:21:17 -07:00
drop_monitor.c genetlink: start to validate reserved header bytes 2022-08-29 12:47:15 +01:00
dst_cache.c wireguard: device: reset peer src endpoint when netns exits 2021-11-29 19:50:45 -08:00
dst.c net: rename reference+tracking helpers 2022-06-09 21:52:55 -07:00
failover.c net: rename reference+tracking helpers 2022-06-09 21:52:55 -07:00
fib_notifier.c
fib_rules.c fib: expand fib_rule_policy 2021-12-16 07:18:35 -08:00
filter.c bpf: tcp: Stop bpf_setsockopt(TCP_CONGESTION) in init ops to recur itself 2022-09-29 09:25:47 -07:00
flow_dissector.c bpf, flow_dissector: Introduce BPF_FLOW_DISSECTOR_CONTINUE retcode for bpf progs 2022-08-23 22:47:55 +02:00
flow_offload.c flow_offload: Introduce flow_match_pppoe 2022-07-26 10:49:27 -07:00
gen_estimator.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
gen_stats.c net: sched: fix misuse of qcpu->backlog in gnet_stats_add_queue_cpu 2022-08-16 19:38:20 -07:00
gro_cells.c net: Fix data-races around netdev_max_backlog. 2022-08-24 13:46:57 +01:00
gro.c net: allow gro_max_size to exceed 65536 2022-05-16 10:18:56 +01:00
hwbm.c
link_watch.c net: rename reference+tracking helpers 2022-06-09 21:52:55 -07:00
lwt_bpf.c bpf, lwt: Fix crash when using bpf_skb_set_tunnel_key() from bpf_xmit lwt hook 2022-04-22 17:45:25 +02:00
lwtunnel.c lwtunnel: Validate RTA_ENCAP_TYPE attribute length 2021-12-31 14:31:59 +00:00
Makefile net: skb: use auto-generation to convert skb drop reason to string 2022-06-07 12:51:41 +02:00
neighbour.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-08-25 16:07:42 -07:00
net_namespace.c net: set proper memcg for net_init hooks allocations 2022-06-16 19:48:31 -07:00
net-procfs.c net: extract a few internals from netdevice.h 2022-04-07 20:32:09 -07:00
net-sysfs.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-06-23 12:33:24 -07:00
net-sysfs.h
net-traces.c tcp: add tracepoint for checksum errors 2021-05-14 15:26:03 -07:00
netclassid_cgroup.c core: Variable type completion 2022-08-31 09:40:34 +01:00
netevent.c net: core: Correct function name netevent_unregister_notifier() in the kerneldoc 2021-03-28 17:56:56 -07:00
netpoll.c net: move from strlcpy with unused retval to strscpy 2022-08-22 18:06:18 -07:00
netprio_cgroup.c bpf, cgroups: Fix cgroup v2 fallback on v1/v2 mixed mode 2021-09-13 16:35:58 -07:00
of_net.c Revert "of: net: support NVMEM cells with MAC in text format" 2022-01-12 14:14:36 +00:00
page_pool.c - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe 2022-08-05 16:32:45 -07:00
pktgen.c net: rename reference+tracking helpers 2022-06-09 21:52:55 -07:00
ptp_classifier.c ptp: Add generic PTP is_sync() function 2022-03-07 11:31:34 +00:00
request_sock.c
rtnetlink.c net: rtnetlink: use netif_oper_up instead of open code 2022-09-01 20:09:23 -07:00
scm.c memcg: enable accounting for scm_fp_list objects 2021-07-20 06:00:38 -07:00
secure_seq.c tcp: Fix data-races around sysctl knobs related to SYN option. 2022-07-20 10:14:49 +01:00
selftests.c net: core: constify mac addrs in selftests 2021-10-24 13:59:44 +01:00
skbuff.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-08-25 16:07:42 -07:00
skmsg.c skmsg: Schedule psock work if the cached skb exists on the psock 2022-09-26 17:48:05 +02:00
sock_destructor.h skb_expand_head() adjust skb->truesize incorrectly 2021-10-22 12:35:51 -07:00
sock_diag.c net: Don't include filter.h from net/sock.h 2021-12-29 08:48:14 -08:00
sock_map.c Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2022-08-17 20:29:36 -07:00
sock_reuseport.c tcp: Fix data-races around sysctl_tcp_migrate_req. 2022-07-18 12:21:54 +01:00
sock.c Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2022-09-06 23:21:18 +02:00
stream.c net: If sock is dead don't access sock's sk_wq in sk_stream_wait_memory 2022-09-26 17:43:43 +02:00
sysctl_net_core.c net: Fix data-races around weight_p and dev_weight_[rt]x_bias. 2022-08-24 13:46:57 +01:00
timestamping.c
tso.c
utils.c net: core: Use csum_replace_by_diff() and csum_sub() instead of opencoding 2022-02-21 11:40:44 +00:00
xdp.c Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2022-03-22 11:18:49 -07:00