From: Cong Wang xiyou.wangcong@gmail.com
[ Upstream commit 0d1c3530e1bd38382edef72591b78e877e0edcd3 ]
In commit 599be01ee567 ("net_sched: fix an OOB access in cls_tcindex") I moved cp->hash calculation before the first tcindex_alloc_perfect_hash(), but cp->alloc_hash is left untouched. This difference could lead to another out of bound access.
cp->alloc_hash should always be the size allocated, we should update it after this tcindex_alloc_perfect_hash().
Reported-and-tested-by: syzbot+dcc34d54d68ef7d2d53d@syzkaller.appspotmail.com Reported-and-tested-by: syzbot+c72da7b9ed57cde6fca2@syzkaller.appspotmail.com Fixes: 599be01ee567 ("net_sched: fix an OOB access in cls_tcindex") Cc: Jamal Hadi Salim jhs@mojatatu.com Cc: Jiri Pirko jiri@resnulli.us Signed-off-by: Cong Wang xiyou.wangcong@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/sched/cls_tcindex.c | 1 + 1 file changed, 1 insertion(+)
--- a/net/sched/cls_tcindex.c +++ b/net/sched/cls_tcindex.c @@ -293,6 +293,7 @@ tcindex_set_parms(struct net *net, struc sizeof(*r) * cp->hash, GFP_KERNEL); if (!cp->perfect) goto errout; + cp->alloc_hash = cp->hash; for (i = 0; i < min(cp->hash, p->hash); i++) tcf_exts_init(&cp->perfect[i].exts, TCA_TCINDEX_ACT, TCA_TCINDEX_POLICE);