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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, LiLiang <liali@redhat.com>,
        Ivan Vecera <ivecera@redhat.com>,
        Michal Kubecek <mkubecek@suse.cz>,
        Jakub Kicinski <kuba@kernel.org>
Subject: [PATCH 5.10 03/63] ethtool: fix error paths in ethnl_set_channels()
Date:   Mon,  4 Jan 2021 16:56:56 +0100
Message-Id: <20210104155708.972099071@linuxfoundation.org>
In-Reply-To: <20210104155708.800470590@linuxfoundation.org>
References: <20210104155708.800470590@linuxfoundation.org>
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From: Ivan Vecera <ivecera@redhat.com>

[ Upstream commit ef72cd3c5ce168829c6684ecb2cae047d3493690 ]

Fix two error paths in ethnl_set_channels() to avoid lock-up caused
but unreleased RTNL.

Fixes: e19c591eafad ("ethtool: set device channel counts with CHANNELS_SET request")
Reported-by: LiLiang <liali@redhat.com>
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
Reviewed-by: Michal Kubecek <mkubecek@suse.cz>
Link: https://lore.kernel.org/r/20201215090810.801777-1-ivecera@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/ethtool/channels.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/net/ethtool/channels.c
+++ b/net/ethtool/channels.c
@@ -194,8 +194,9 @@ int ethnl_set_channels(struct sk_buff *s
 	if (netif_is_rxfh_configured(dev) &&
 	    !ethtool_get_max_rxfh_channel(dev, &max_rx_in_use) &&
 	    (channels.combined_count + channels.rx_count) <= max_rx_in_use) {
+		ret = -EINVAL;
 		GENL_SET_ERR_MSG(info, "requested channel counts are too low for existing indirection table settings");
-		return -EINVAL;
+		goto out_ops;
 	}
 
 	/* Disabling channels, query zero-copy AF_XDP sockets */
@@ -203,8 +204,9 @@ int ethnl_set_channels(struct sk_buff *s
 		       min(channels.rx_count, channels.tx_count);
 	for (i = from_channel; i < old_total; i++)
 		if (xsk_get_pool_from_qid(dev, i)) {
+			ret = -EINVAL;
 			GENL_SET_ERR_MSG(info, "requested channel counts are too low for existing zerocopy AF_XDP sockets");
-			return -EINVAL;
+			goto out_ops;
 		}
 
 	ret = dev->ethtool_ops->set_channels(dev, &channels);