From: ZhengHan Wang <wzhmmmmm@gmail.com>
To: marcel@holtmann.org, johan.hedberg@gmail.com, luiz.dentz@gmail.com
Cc: linux-bluetooth@vger.kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, ZhengHan Wang <wzhmmmmm@gmail.com>
Subject: [PATCH] Bluetooth: Fix double free in hci_conn_cleanup
Date: Thu, 9 Mar 2023 15:46:45 +0800 [thread overview]
Message-ID: <20230309074645.74309-1-wzhmmmmm@gmail.com> (raw)
syzbot reports a slab use-after-free in hci_conn_hash_flush [1].
After releasing an object using hci_conn_del_sysfs in the
hci_conn_cleanup function, releasing the same object again
using the hci_dev_put and hci_conn_put functions causes a double free.
Here's a simplified flow:
hci_conn_del_sysfs:
hci_dev_put
put_device
kobject_put
kref_put
kobject_release
kobject_cleanup
kfree_const
kfree(name)
hci_dev_put:
...
kfree(name)
hci_conn_put:
put_device
...
kfree(name)
This patch drop the hci_dev_put and hci_conn_put function
call in hci_conn_cleanup function, because the object is
freed in hci_conn_del_sysfs function.
Link: https://syzkaller.appspot.com/bug?id=1bb51491ca5df96a5f724899d1dbb87afda61419 [1]
Signed-off-by: ZhengHan Wang <wzhmmmmm@gmail.com>
---
net/bluetooth/hci_conn.c | 4 ----
1 file changed, 4 deletions(-)
diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index acf563fbdfd9..a0ccbef34bc2 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -152,10 +152,6 @@ static void hci_conn_cleanup(struct hci_conn *conn)
hci_conn_del_sysfs(conn);
debugfs_remove_recursive(conn->debugfs);
-
- hci_dev_put(hdev);
-
- hci_conn_put(conn);
}
static void le_scan_cleanup(struct work_struct *work)
--
2.25.1
reply other threads:[~2023-03-09 7:49 UTC|newest]
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