linux-kernel - Re: [syzbot] [fs?] KASAN: slab-use-after-free Read in lockref

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <tencent_AAEF765567CA3DCF377696B436244B387509@qq.com>
Date: Wed, 17 Jul 2024 11:24:37 +0800
From: Edward Adam Davis <eadavis@...com>
To: syzbot+d5dc2801166df6d34774@...kaller.appspotmail.com
Cc: linux-kernel@...r.kernel.org,
	syzkaller-bugs@...glegroups.com
Subject: Re: [syzbot] [fs?] KASAN: slab-use-after-free Read in lockref_get

before remove debugfs_dir set reference pointer to NULL

#syz test: linux-next 58f9416d413a

diff --git a/net/mac80211/debugfs_netdev.c b/net/mac80211/debugfs_netdev.c
index 68596ef78b15..b9961edf6fa5 100644
--- a/net/mac80211/debugfs_netdev.c
+++ b/net/mac80211/debugfs_netdev.c
@@ -1019,8 +1019,10 @@ void ieee80211_debugfs_remove_netdev(struct ieee80211_sub_if_data *sdata)
 	if (!sdata->vif.debugfs_dir)
 		return;
 
-	debugfs_remove_recursive(sdata->vif.debugfs_dir);
+	struct dentry *debugfs_dir = sdata->vif.debugfs_dir;
+
 	sdata->vif.debugfs_dir = NULL;
+	debugfs_remove_recursive(debugfs_dir);
 	sdata->debugfs.subdir_stations = NULL;
 }
 
diff --git a/net/mac80211/debugfs_sta.c b/net/mac80211/debugfs_sta.c
index 1e9389c49a57..357f310ec75f 100644
--- a/net/mac80211/debugfs_sta.c
+++ b/net/mac80211/debugfs_sta.c
@@ -1284,6 +1284,11 @@ void ieee80211_sta_debugfs_add(struct sta_info *sta)
 
 void ieee80211_sta_debugfs_remove(struct sta_info *sta)
 {
+	struct ieee80211_sub_if_data *sdata = sta->sdata;
+
+	if (!sdata->vif.debugfs_dir)
+		return;
+
 	debugfs_remove_recursive(sta->debugfs_dir);
 	sta->debugfs_dir = NULL;
 }