From c4453d2833671e3a9f6bd52f0f581056c3736386 Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Wed, 11 Mar 2020 22:42:28 -0700 Subject: [PATCH] net_sched: keep alloc_hash updated after hash allocation [ 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 Cc: Jiri Pirko Signed-off-by: Cong Wang Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/sched/cls_tcindex.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/sched/cls_tcindex.c b/net/sched/cls_tcindex.c index 3e1695b66e31..ab66e2b38e66 100644 --- a/net/sched/cls_tcindex.c +++ b/net/sched/cls_tcindex.c @@ -325,6 +325,7 @@ tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base, if (tcindex_alloc_perfect_hash(cp) < 0) goto errout; + cp->alloc_hash = cp->hash; for (i = 0; i < min(cp->hash, p->hash); i++) cp->perfect[i].res = p->perfect[i].res; balloc = 1; -- 2.20.1