linux/net
D. Wythe e6d71b437a net/smc: avoid data corruption caused by decline
We found a data corruption issue during testing of SMC-R on Redis
applications.

The benchmark has a low probability of reporting a strange error as
shown below.

"Error: Protocol error, got "\xe2" as reply type byte"

Finally, we found that the retrieved error data was as follows:

0xE2 0xD4 0xC3 0xD9 0x04 0x00 0x2C 0x20 0xA6 0x56 0x00 0x16 0x3E 0x0C
0xCB 0x04 0x02 0x01 0x00 0x00 0x20 0x00 0x00 0x00 0x00 0x00 0x00 0x00
0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0xE2

It is quite obvious that this is a SMC DECLINE message, which means that
the applications received SMC protocol message.
We found that this was caused by the following situations:

client                  server
        ¦  clc proposal
        ------------->
        ¦  clc accept
        <-------------
        ¦  clc confirm
        ------------->
wait llc confirm
			send llc confirm
        ¦failed llc confirm
        ¦   x------
(after 2s)timeout
                        wait llc confirm rsp

wait decline

(after 1s) timeout
                        (after 2s) timeout
        ¦   decline
        -------------->
        ¦   decline
        <--------------

As a result, a decline message was sent in the implementation, and this
message was read from TCP by the already-fallback connection.

This patch double the client timeout as 2x of the server value,
With this simple change, the Decline messages should never cross or
collide (during Confirm link timeout).

This issue requires an immediate solution, since the protocol updates
involve a more long-term solution.

Fixes: 0fb0b02bd6 ("net/smc: adapt SMC client code to use the LLC flow")
Signed-off-by: D. Wythe <alibuda@linux.alibaba.com>
Reviewed-by: Wen Gu <guwen@linux.alibaba.com>
Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-11-22 12:10:19 +00:00
..
6lowpan
9p 9p/net: fix possible memory leak in p9_check_errors() 2023-10-27 12:44:13 +09:00
802 net: fill in MODULE_DESCRIPTION()s under net/802* 2023-10-28 11:29:28 +01:00
8021q net: fill in MODULE_DESCRIPTION()s under net/802* 2023-10-28 11:29:28 +01:00
appletalk appletalk: remove special handling code for ipddp 2023-10-13 17:59:32 -07:00
atm net: atm: Remove redundant check. 2023-10-23 08:45:25 +01:00
ax25
batman-adv
bluetooth This update includes the following changes: 2023-11-02 16:15:30 -10:00
bpf bpf: Add __bpf_kfunc_{start,end}_defs macros 2023-11-01 22:33:53 -07:00
bpfilter
bridge netfilter: nf_conntrack_bridge: initialize err to 0 2023-11-14 16:16:21 +01:00
caif
can
ceph This update includes the following changes: 2023-11-02 16:15:30 -10:00
core bpf, netkit: Add indirect call wrapper for fetching peer dev 2023-11-20 10:15:16 -08:00
dcb
dccp dccp/tcp: Call security_inet_conn_request() after setting IPv6 addresses. 2023-11-02 12:56:03 +01:00
devlink netlink: specs: devlink: add forgotten port function caps enum values 2023-11-01 22:13:43 -07:00
dns_resolver
dsa net: dsa: Rename IFLA_DSA_MASTER to IFLA_DSA_CONDUIT 2023-10-24 13:08:14 -07:00
ethernet
ethtool ethtool: untangle the linkmode and ethtool headers 2023-10-20 12:47:33 +01:00
handshake Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2023-10-26 13:46:28 -07:00
hsr hsr: Prevent use after free in prp_create_tagged_frame() 2023-11-01 22:26:04 -07:00
ieee802154
ife
ipv4 ipv4: Correct/silence an endian warning in __ip_do_redirect 2023-11-21 12:55:22 +01:00
ipv6 Including fixes from netfilter and bpf. 2023-11-09 17:09:35 -08:00
iucv
kcm net: kcm: fill in MODULE_DESCRIPTION() 2023-11-08 18:17:44 -08:00
key
l2tp
l3mdev
lapb
llc llc: verify mac len before reading mac header 2023-11-01 22:21:32 -07:00
mac80211 wireless-next patches for v6.7 2023-10-26 20:27:58 -07:00
mac802154
mctp
mpls
mptcp net: fill in MODULE_DESCRIPTION()s for SOCK_DIAG modules 2023-11-19 20:09:13 +00:00
ncsi Revert ncsi: Propagate carrier gain/loss events to the NCSI controller 2023-11-15 09:59:44 +00:00
netfilter netfilter: nf_tables: split async and sync catchall in two functions 2023-11-14 16:16:21 +01:00
netlabel
netlink netlink: fill in missing MODULE_DESCRIPTION() 2023-11-03 11:42:48 +00:00
netrom
nfc nfc: nci: fix possible NULL pointer dereference in send_acknowledge() 2023-10-16 17:34:53 -07:00
nsh
openvswitch net/sched: act_ct: Always fill offloading tuple iifidx 2023-11-08 17:47:08 -08:00
packet net: fill in MODULE_DESCRIPTION()s for SOCK_DIAG modules 2023-11-19 20:09:13 +00:00
phonet
psample
qrtr
rds
rfkill
rose
rxrpc rxrpc: Defer the response to a PING ACK until we've parsed it 2023-11-17 02:50:33 +00:00
sched net: sched: do not offload flows with a helper in act_ct 2023-11-16 10:10:51 +01:00
sctp net: fill in MODULE_DESCRIPTION()s for SOCK_DIAG modules 2023-11-19 20:09:13 +00:00
smc net/smc: avoid data corruption caused by decline 2023-11-22 12:10:19 +00:00
strparser
sunrpc NFS client updates for Linux 6.7 2023-11-08 13:39:16 -08:00
switchdev
tipc net: fill in MODULE_DESCRIPTION()s for SOCK_DIAG modules 2023-11-19 20:09:13 +00:00
tls tls: don't reset prot->aad_size and prot->tail_size for TLS_HW 2023-10-23 10:15:09 -07:00
unix net: fill in MODULE_DESCRIPTION()s for SOCK_DIAG modules 2023-11-19 20:09:13 +00:00
vmw_vsock net: fill in MODULE_DESCRIPTION()s for SOCK_DIAG modules 2023-11-19 20:09:13 +00:00
wireless wireless-next patches for v6.7 2023-10-26 20:27:58 -07:00
x25
xdp net: fill in MODULE_DESCRIPTION()s for SOCK_DIAG modules 2023-11-19 20:09:13 +00:00
xfrm Including fixes from netfilter and bpf. 2023-11-09 17:09:35 -08:00
compat.c
devres.c
Kconfig
Kconfig.debug
Makefile
socket.c bpf: Add __bpf_hook_{start,end} macros 2023-11-01 22:33:53 -07:00
sysctl_net.c