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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>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.9 04/19] mac80211_hwsim: call ieee80211_tx_prepare_skb under RCU protection
Date:   Mon, 16 May 2022 21:36:17 +0200
Message-Id: <20220516193613.629673854@linuxfoundation.org>
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From: Johannes Berg <johannes.berg@intel.com>

[ Upstream commit 9e2db50f1ef2238fc2f71c5de1c0418b7a5b0ea2 ]

This is needed since it might use (and pass out) pointers to
e.g. keys protected by RCU. Can't really happen here as the
frames aren't encrypted, but we need to still adhere to the
rules.

Fixes: cacfddf82baf ("mac80211_hwsim: initialize ieee80211_tx_info at hw_scan_work")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Link: https://lore.kernel.org/r/20220505230421.5f139f9de173.I77ae111a28f7c0e9fd1ebcee7f39dbec5c606770@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/wireless/mac80211_hwsim.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c
index a34647efb5ea..2cd1b3cfcc09 100644
--- a/drivers/net/wireless/mac80211_hwsim.c
+++ b/drivers/net/wireless/mac80211_hwsim.c
@@ -1987,11 +1987,13 @@ static void hw_scan_work(struct work_struct *work)
 				memcpy(skb_put(probe, req->ie_len), req->ie,
 				       req->ie_len);
 
+			rcu_read_lock();
 			if (!ieee80211_tx_prepare_skb(hwsim->hw,
 						      hwsim->hw_scan_vif,
 						      probe,
 						      hwsim->tmp_chan->band,
 						      NULL)) {
+				rcu_read_unlock();
 				kfree_skb(probe);
 				continue;
 			}
@@ -1999,6 +2001,7 @@ static void hw_scan_work(struct work_struct *work)
 			local_bh_disable();
 			mac80211_hwsim_tx_frame(hwsim->hw, probe,
 						hwsim->tmp_chan);
+			rcu_read_unlock();
 			local_bh_enable();
 		}
 	}
-- 
2.35.1