[PATCH 4.19 163/421] net: sched: fix warning in tcindex_alloc_perfect_hash

Greg Kroah-Hartman
2021-07-19T16:17:42Z

From: Pavel Skripkin <paskripkin@gmail.com>

[ Upstream commit 3f2db250099f46988088800052cdf2332c7aba61 ]

Syzbot reported warning in tcindex_alloc_perfect_hash. The problem
was in too big cp->hash, which triggers warning in kmalloc. Since
cp->hash comes from userspace, there is no need to warn if value
is not correct

Fixes: b9a24bb76bf6 ("net_sched: properly handle failure case of tcf_exts_init()")
Reported-and-tested-by: syzbot+1071ad60cd7df39fdadb@syzkaller.appspotmail.com
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Acked-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/sched/cls_tcindex.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/sched/cls_tcindex.c b/net/sched/cls_tcindex.c
index e41bc5ecaa09..4070197f9543 100644
--- a/net/sched/cls_tcindex.c
+++ b/net/sched/cls_tcindex.c
@@ -276,7 +276,7 @@ static int tcindex_alloc_perfect_hash(struct net *net, struct tcindex_data *cp)
int i, err = 0;

cp->perfect = kcalloc(cp->hash, sizeof(struct tcindex_filter_result),
- GFP_KERNEL);
+ GFP_KERNEL | __GFP_NOWARN);
if (!cp->perfect)
return -ENOMEM;

--
2.30.2