kernel: ethtool: kernel buffer overflow in ETHTOOL_GRXCLSRLALL

[Eugene Teo <eugeneteo () kernel sg>]

FYI, "On a 32-bit machine, info.rule_cnt >= 0x40000000 leads to integer 
overflow and the buffer may be smaller than needed.  Since 
ETHTOOL_GRXCLSRLALL is unprivileged, this can presumably be used for at 
least denial of service." This was introduced in v2.6.27-rc1 via 
upstream commit 0853ad66. Also see commit 59089d8d.

Reference:
http://thread.gmane.org/gmane.linux.network/164869
https://bugzilla.redhat.com/show_bug.cgi?id=608950

I'm not requesting a CVE name for this as it did not affect any of our 
Red Hat supported Linux kernels.

Thanks, Eugene
--
main(i) { putchar(182623909 >> (i-1) * 5&31|!!(i<7)<<6) && main(++i); }