linux-stable.git/net/core, branch linux-5.17.y

net, neigh: Set lower cap for neigh_managed_work rearming

2022-06-14T16:41:37+00:00

[ Upstream commit ed6cd6a17896561b9f51ab4c0d9bbb29e762b597 ]

Yuwei reported that plain reuse of DELAY_PROBE_TIME to rearm work queue
in neigh_managed_work is problematic if user explicitly configures the
DELAY_PROBE_TIME to 0 for a neighbor table. Such misconfig can then hog
CPU to 100% processing the system work queue. Instead, set lower interval
bound to HZ which is totally sufficient. Yuwei is additionally looking
into making the interval separately configurable from DELAY_PROBE_TIME.

Reported-by: Yuwei Wang 
Signed-off-by: Daniel Borkmann 
Link: https://lore.kernel.org/netdev/797c3c53-ce1b-9f60-e253-cda615788f4a@iogearbox.net
Reviewed-by: Nikolay Aleksandrov 
Link: https://lore.kernel.org/r/3b8c5aa906c52c3a8c995d1b2e8ccf650ea7c716.1653432794.git.daniel@iogearbox.net
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

netfilter: nf_tables: bail out early if hardware offload is not supported

2022-06-14T16:41:30+00:00

[ Upstream commit 3a41c64d9c1185a2f3a184015e2a9b78bfc99c71 ]

If user requests for NFT_CHAIN_HW_OFFLOAD, then check if either device
provides the .ndo_setup_tc interface or there is an indirect flow block
that has been registered. Otherwise, bail out early from the preparation
phase. Moreover, validate that family == NFPROTO_NETDEV and hook is
NF_NETDEV_INGRESS.

Fixes: c9626a2cbdb2 ("netfilter: nf_tables: add hardware offload support")
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

tcp: add accessors to read/set tp->snd_cwnd

2022-06-14T16:41:22+00:00

[ Upstream commit 40570375356c874b1578e05c1dcc3ff7c1322dbe ]

We had various bugs over the years with code
breaking the assumption that tp->snd_cwnd is greater
than zero.

Lately, syzbot reported the WARN_ON_ONCE(!tp->prior_cwnd) added
in commit 8b8a321ff72c ("tcp: fix zero cwnd in tcp_cwnd_reduction")
can trigger, and without a repro we would have to spend
considerable time finding the bug.

Instead of complaining too late, we want to catch where
and when tp->snd_cwnd is set to an illegal value.

Signed-off-by: Eric Dumazet 
Suggested-by: Yuchung Cheng 
Cc: Neal Cardwell 
Acked-by: Yuchung Cheng 
Link: https://lore.kernel.org/r/20220405233538.947344-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

net: remove two BUG() from skb_checksum_help()

2022-06-09T08:25:25+00:00

[ Upstream commit d7ea0d9df2a6265b2b180d17ebc64b38105968fc ]

I have a syzbot report that managed to get a crash in skb_checksum_help()

If syzbot can trigger these BUG(), it makes sense to replace
them with more friendly WARN_ON_ONCE() since skb_checksum_help()
can instead return an error code.

Note that syzbot will still crash there, until real bug is fixed.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

bpf: Fix usage of trace RCU in local storage.

2022-06-06T06:47:56+00:00

commit dcf456c9a095a6e71f53d6f6f004133ee851ee70 upstream.

bpf_{sk,task,inode}_storage_free() do not need to use
call_rcu_tasks_trace as no BPF program should be accessing the owner
as it's being destroyed. The only other reader at this point is
bpf_local_storage_map_free() which uses normal RCU.

The only path that needs trace RCU are:

* bpf_local_storage_{delete,update} helpers
* map_{delete,update}_elem() syscalls

Fixes: 0fe4b381a59e ("bpf: Allow bpf_local_storage to be used by sleepable programs")
Signed-off-by: KP Singh 
Signed-off-by: Alexei Starovoitov 
Acked-by: Martin KaFai Lau 
Link: https://lore.kernel.org/bpf/20220418155158.2865678-1-kpsingh@kernel.org
Signed-off-by: Greg Kroah-Hartman

bpf: Enlarge offset check value to INT_MAX in bpf_skb_{load,store}_bytes

2022-06-06T06:47:56+00:00

commit 45969b4152c1752089351cd6836a42a566d49bcf upstream.

The data length of skb frags + frag_list may be greater than 0xffff, and
skb_header_pointer can not handle negative offset. So, here INT_MAX is used
to check the validity of offset. Add the same change to the related function
skb_store_bytes.

Fixes: 05c74e5e53f6 ("bpf: add bpf_skb_load_bytes helper")
Signed-off-by: Liu Jian 
Signed-off-by: Daniel Borkmann 
Acked-by: Song Liu 
Link: https://lore.kernel.org/bpf/20220416105801.88708-2-liujian56@huawei.com
Signed-off-by: Greg Kroah-Hartman

net: fix wrong network header length

2022-05-25T07:59:14+00:00

[ Upstream commit cf3ab8d4a797960b4be20565abb3bcd227b18a68 ]

When clatd starts with ebpf offloaing, and NETIF_F_GRO_FRAGLIST is enable,
several skbs are gathered in skb_shinfo(skb)->frag_list. The first skb's
ipv6 header will be changed to ipv4 after bpf_skb_proto_6_to_4,
network_header\transport_header\mac_header have been updated as ipv4 acts,
but other skbs in frag_list didnot update anything, just ipv6 packets.

udp_queue_rcv_skb will call skb_segment_list to traverse other skbs in
frag_list and make sure right udp payload is delivered to user space.
Unfortunately, other skbs in frag_list who are still ipv6 packets are
updated like the first skb and will have wrong transport header length.

e.g.before bpf_skb_proto_6_to_4,the first skb and other skbs in frag_list
has the same network_header(24)& transport_header(64), after
bpf_skb_proto_6_to_4, ipv6 protocol has been changed to ipv4, the first
skb's network_header is 44,transport_header is 64, other skbs in frag_list
didnot change.After skb_segment_list, the other skbs in frag_list has
different network_header(24) and transport_header(44), so there will be 20
bytes different from original,that is difference between ipv6 header and
ipv4 header. Just change transport_header to be the same with original.

Actually, there are two solutions to fix it, one is traversing all skbs
and changing every skb header in bpf_skb_proto_6_to_4, the other is
modifying frag_list skb's header in skb_segment_list. Considering
efficiency, adopt the second one--- when the first skb and other skbs in
frag_list has different network_header length, restore them to make sure
right udp payload is delivered to user space.

Signed-off-by: Lina Wang 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net: fix dev_fill_forward_path with pppoe + bridge

2022-05-25T07:59:07+00:00

[ Upstream commit cf2df74e202d81b09f09d84c2d8903e0e87e9274 ]

When calling dev_fill_forward_path on a pppoe device, the provided destination
address is invalid. In order for the bridge fdb lookup to succeed, the pppoe
code needs to update ctx->daddr to the correct value.
Fix this by storing the address inside struct net_device_path_ctx

Fixes: f6efc675c9dd ("net: ppp: resolve forwarding path for bridge pppoe devices")
Signed-off-by: Felix Fietkau 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

tcp: resalt the secret every 10 seconds

2022-05-18T08:28:18+00:00

[ Upstream commit 4dfa9b438ee34caca4e6a4e5e961641807367f6f ]

In order to limit the ability for an observer to recognize the source
ports sequence used to contact a set of destinations, we should
periodically shuffle the secret. 10 seconds looks effective enough
without causing particular issues.

Cc: Moshe Kol 
Cc: Yossi Gilad 
Cc: Amit Klein 
Cc: Jason A. Donenfeld 
Tested-by: Willy Tarreau 
Signed-off-by: Eric Dumazet 
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

secure_seq: use the 64 bits of the siphash for port offset calculation

2022-05-18T08:28:17+00:00

[ Upstream commit b2d057560b8107c633b39aabe517ff9d93f285e3 ]

SipHash replaced MD5 in secure_ipv{4,6}_port_ephemeral() via commit
7cd23e5300c1 ("secure_seq: use SipHash in place of MD5"), but the output
remained truncated to 32-bit only. In order to exploit more bits from the
hash, let's make the functions return the full 64-bit of siphash_3u32().
We also make sure the port offset calculation in __inet_hash_connect()
remains done on 32-bit to avoid the need for div_u64_rem() and an extra
cost on 32-bit systems.

Cc: Jason A. Donenfeld 
Cc: Moshe Kol 
Cc: Yossi Gilad 
Cc: Amit Klein 
Reviewed-by: Eric Dumazet 
Signed-off-by: Willy Tarreau 
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin