diff mbox series

[4.9,042/102] net_sched: keep alloc_hash updated after hash allocation

Message ID 20200401161540.798375716@linuxfoundation.org
State Superseded
Headers show
Series None | expand

Commit Message

Greg KH April 1, 2020, 4:17 p.m. UTC 
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(+)
diff mbox series

Patch

--- a/net/sched/cls_tcindex.c
+++ b/net/sched/cls_tcindex.c
@@ -325,6 +325,7 @@  tcindex_set_parms(struct net *net, struc
 
 		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;