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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Pavel Skripkin <paskripkin@gmail.com>,
        Cong Wang <cong.wang@bytedance.com>,
        "David S. Miller" <davem@davemloft.net>,
        Sasha Levin <sashal@kernel.org>,
        syzbot+1071ad60cd7df39fdadb@syzkaller.appspotmail.com
Subject: [PATCH 5.12 514/700] net: sched: fix warning in tcindex_alloc_perfect_hash
Date:   Mon, 12 Jul 2021 08:09:57 +0200
Message-Id: <20210712061031.219924821@linuxfoundation.org>
In-Reply-To: <20210712060924.797321836@linuxfoundation.org>
References: <20210712060924.797321836@linuxfoundation.org>
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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 c4007b9cd16d..5b274534264c 100644
--- a/net/sched/cls_tcindex.c
+++ b/net/sched/cls_tcindex.c
@@ -304,7 +304,7 @@ 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