From 2f1f199b8b5751dfd19159a47abf625822d6c35b Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Tue, 22 Sep 2020 10:14:04 +0800 Subject: [PATCH] net_sched: keep alloc_hash updated after hash allocation stable inclusion from linux-4.19.114 commit 557d015ffb27b672e24e6ad141fd887783871dc2 -------------------------------- [ 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 Signed-off-by: Yang Yingliang Signed-off-by: Li Aichun Reviewed-by: guodeqing Signed-off-by: Yang Yingliang --- 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 8f93a264c7eb..79d8f3f79017 100644 --- a/net/sched/cls_tcindex.c +++ b/net/sched/cls_tcindex.c @@ -357,6 +357,7 @@ tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base, if (tcindex_alloc_perfect_hash(net, 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; -- GitLab