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From:   Sasha Levin <Alexander.Levin@microsoft.com>
To:     "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "stable@vger.kernel.org" <stable@vger.kernel.org>
CC:     Hangbin Liu <liuhangbin@gmail.com>,
        Pablo Neira Ayuso <pablo@netfilter.org>,
        Sasha Levin <Alexander.Levin@microsoft.com>
Subject: [PATCH AUTOSEL for 4.14 058/110] netfilter: nf_tables: fix potential
 NULL-ptr deref in nf_tables_dump_obj_done()
Thread-Topic: [PATCH AUTOSEL for 4.14 058/110] netfilter: nf_tables: fix
 potential NULL-ptr deref in nf_tables_dump_obj_done()
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Date:   Sat, 3 Feb 2018 18:00:56 +0000
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From: Hangbin Liu <liuhangbin@gmail.com>

[ Upstream commit 8bea728dce8972e534e6b99fd550f7b5cc3864e8 ]

If there is no NFTA_OBJ_TABLE and NFTA_OBJ_TYPE, the c.data will be NULL in
nf_tables_getobj(). So before free filter->table in nf_tables_dump_obj_done=
(),
we need to check if filter is NULL first.

Fixes: e46abbcc05aa ("netfilter: nf_tables: Allow table names of up to 255 =
chars")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Acked-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
 net/netfilter/nf_tables_api.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index ce49946f755e..5b504aa653f5 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -4596,8 +4596,10 @@ static int nf_tables_dump_obj_done(struct netlink_ca=
llback *cb)
 {
 	struct nft_obj_filter *filter =3D cb->data;
=20
-	kfree(filter->table);
-	kfree(filter);
+	if (filter) {
+		kfree(filter->table);
+		kfree(filter);
+	}
=20
 	return 0;
 }
--=20
2.11.0