From:   Natalia Petrova <n.petrova@fintech.ru>
To:     <stable@vger.kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CC:     Natalia Petrova <n.petrova@fintech.ru>,
        Jesse Brandeburg <jesse.brandeburg@intel.com>,
        Tony Nguyen <anthony.l.nguyen@intel.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        <intel-wired-lan@lists.osuosl.org>, <netdev@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <lvc-project@linuxtesting.org>
Subject: [PATCH v2] i40e: Add checking for null for nlmsg_find_attr()
Date:   Tue, 31 Jan 2023 01:11:06 +0300
Message-ID: <20230130221106.19267-1-n.petrova@fintech.ru>
In-Reply-To: <20230125141328.8479-1-n.petrova@fintech.ru>
References: 
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The result of nlmsg_find_attr() 'br_spec' is dereferenced in
nla_for_each_nested(), but it can take null value in nla_find() function,
which will result in an error.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 51616018dd1b ("i40e: Add support for getlink, setlink ndo ops")
Signed-off-by: Natalia Petrova <n.petrova@fintech.ru>
Reviewed-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
---
v2: The remark about the error code by Simon Horman <simon.horman@corigine.com> 
was taken into account; return value -ENOENT was changed to -EINVAL.
 drivers/net/ethernet/intel/i40e/i40e_main.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 53d0083e35da..4626d2a1af91 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -13167,6 +13167,8 @@ static int i40e_ndo_bridge_setlink(struct net_device *dev,
 	}
 
 	br_spec = nlmsg_find_attr(nlh, sizeof(struct ifinfomsg), IFLA_AF_SPEC);
+	if (!br_spec)
+		return -EINVAL;
 
 	nla_for_each_nested(attr, br_spec, rem) {
 		__u16 mode;
-- 
2.34.1