On 10/10/19 2:50 AM, Cătălin George Feștilă wrote:
What is net.core.netdev_rss_key?
Can be this default setting an insecure issue?
You can see it with this command:
[root@desk mythcat]# sysctl -a --pattern 'net.core.netdev_rss_key'
netdev_rss_key
--------------
RSS (Receive Side Scaling) enabled drivers use a 40 bytes host key that is
randomly generated.
Some user space might need to gather its content even if drivers do not
provide ethtool -x support yet.
myhost:~# cat /proc/sys/net/core/netdev_rss_key
84:50:f4:00:a8:15:d1:a7:e9:7f:1d:60:35:c7:47:25:42:97:74:ca:56:bb:b6:a1:d8: ... (52 bytes
total)
File contains nul bytes if no driver ever called netdev_rss_key_fill() function.
Note:
/proc/sys/net/core/netdev_rss_key contains 52 bytes of key,
but most drivers only use 40 bytes of it.
myhost:~# ethtool -x eth0
RX flow hash indirection table for eth0 with 8 RX ring(s):
0: 0 1 2 3 4 5 6 7
RSS hash key:
84:50:f4:00:a8:15:d1:a7:e9:7f:1d:60:35:c7:47:25:42:97:74:ca:56:bb:b6:a1:d8:43:e3:c9:0c:fd:17:55:c2:3a:4d:69:ed:f1:42:89
https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/6/...
--
If simple questions can be answered with a simple google query then why are there so many
of them?