From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	patches@lists.linux.dev,
	Zilin Guan <zilin@seu.edu.cn>,
	Dawei Feng <dawei.feng@seu.edu.cn>,
	Johannes Berg <johannes.berg@intel.com>
Subject: [PATCH 6.6 1129/1266] wifi: mac80211: fix memory leak in ieee80211_register_hw()
Date: Tue, 21 Jul 2026 17:26:06 +0200
Message-ID: <20260721152507.060191917@linuxfoundation.org>
In-Reply-To: <20260721152441.786066624@linuxfoundation.org>
References: <20260721152441.786066624@linuxfoundation.org>
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6.6-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dawei Feng <dawei.feng@seu.edu.cn>

commit 95fc02722edde02946d0d475221f2b2054d3d8ba upstream.

If kmemdup() fails while copying supported band structures, the error
path jumps to fail_rate. This skips rate_control_deinitialize() and
leaks the initialized local->rate_ctrl.

Fix this by adding a fail_band label that shares the rate-control cleanup
path before falling through to the remaining teardown.

The bug was first flagged by an experimental analysis tool we are
developing for kernel memory-management bugs while analyzing
v6.13-rc1. The tool is still under development and is not yet publicly
available. Manual inspection confirms that the bug is still present in
v7.1-rc7.

An x86_64 allyesconfig build showed no new warnings. As we do not have a
suitable mac80211 device/driver combination to test with, no runtime
testing was able to be performed.

Fixes: 09b4a4faf9d0 ("mac80211: introduce capability flags for VHT EXT NSS support")
Cc: stable@vger.kernel.org
Reviewed-by: Zilin Guan <zilin@seu.edu.cn>
Signed-off-by: Dawei Feng <dawei.feng@seu.edu.cn>
Link: https://patch.msgid.link/20260706143507.146131-1-dawei.feng@seu.edu.cn
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/mac80211/main.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -1410,7 +1410,7 @@ int ieee80211_register_hw(struct ieee802
 		sband = kmemdup(sband, sizeof(*sband), GFP_KERNEL);
 		if (!sband) {
 			result = -ENOMEM;
-			goto fail_rate;
+			goto fail_band;
 		}
 
 		wiphy_dbg(hw->wiphy, "copying sband (band %d) due to VHT EXT NSS BW flag\n",
@@ -1475,6 +1475,7 @@ int ieee80211_register_hw(struct ieee802
 #endif
 	wiphy_unregister(local->hw.wiphy);
  fail_wiphy_register:
+ fail_band:
 	rtnl_lock();
 	rate_control_deinitialize(local);
 	ieee80211_remove_interfaces(local);