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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, Johannes Berg <johannes.berg@intel.com>,
        Luca Coelho <luciano.coelho@intel.com>,
        Kalle Valo <kvalo@codeaurora.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.10 38/54] iwlwifi: queue: bail out on invalid freeing
Date:   Thu, 11 Feb 2021 16:02:22 +0100
Message-Id: <20210211150154.536382640@linuxfoundation.org>
In-Reply-To: <20210211150152.885701259@linuxfoundation.org>
References: <20210211150152.885701259@linuxfoundation.org>
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From: Johannes Berg <johannes.berg@intel.com>

[ Upstream commit 0bed6a2a14afaae240cc431e49c260568488b51c ]

If we find an entry without an SKB, we currently continue, but
that will just result in an infinite loop since we won't increment
the read pointer, and will try the same thing over and over again.
Fix this.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/iwlwifi.20210122144849.abe2dedcc3ac.Ia6b03f9eeb617fd819e56dd5376f4bb8edc7b98a@changeid
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/wireless/intel/iwlwifi/queue/tx.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/queue/tx.c b/drivers/net/wireless/intel/iwlwifi/queue/tx.c
index af0b27a68d84d..9181221a2434d 100644
--- a/drivers/net/wireless/intel/iwlwifi/queue/tx.c
+++ b/drivers/net/wireless/intel/iwlwifi/queue/tx.c
@@ -887,10 +887,8 @@ void iwl_txq_gen2_unmap(struct iwl_trans *trans, int txq_id)
 			int idx = iwl_txq_get_cmd_index(txq, txq->read_ptr);
 			struct sk_buff *skb = txq->entries[idx].skb;
 
-			if (WARN_ON_ONCE(!skb))
-				continue;
-
-			iwl_txq_free_tso_page(trans, skb);
+			if (!WARN_ON_ONCE(!skb))
+				iwl_txq_free_tso_page(trans, skb);
 		}
 		iwl_txq_gen2_free_tfd(trans, txq);
 		txq->read_ptr = iwl_txq_inc_wrap(trans, txq->read_ptr);
-- 
2.27.0