net: sched: em_ipt: validate hook value from netlink

em_ipt_change() accepts the user-provided TCA_EM_IPT_HOOK value
without validating its range.

The value is later used in check_match() as "1 << im->hook".  A hook
value of 32 or greater causes undefined behavior and may undermine the
xt match hook-mask validation.  The value is also passed to
nf_hook_state_init() as a hook index.

Reject hook values outside the supported IPv4/IPv6 Netfilter hook
range after checking the required attributes, before loading the xt
match or allocating the match state.

Reviewed-by: Weibin Liu <liuwb@xiaopeng.com>
Signed-off-by: Fang Xieyan <fangxy@xiaopeng.com>
Signed-off-by: Dave Miller <davem@davem-thinkpadp1gen8.ibmlond.csb>

0 files changed, 0 insertions, 0 deletions