netfilter: nf_conntrack: use RCU safe kfree for conntrack extensions
netfilter: nf_conntrack: use RCU safe kfree for conntrack extensions

Commit 68b80f11 (netfilter: nf_nat: fix RCU races) introduced
RCU protection for freeing extension data when reallocation
moves them to a new location. We need the same protection when
freeing them in nf_ct_ext_free() in order to prevent a
use-after-free by other threads referencing a NAT extension data
via bysource list.

Signed-off-by: Michal Kubecek <48ad0bdf47651f7a71905c605c8960f443623cd5@suse.cz>
Signed-off-by: Pablo Neira Ayuso <707d14912bb250caf67dfe0ea4035681fbfc4f56@netfilter.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs