diff options
| author | Ruihan Li <lrh2000@pku.edu.cn> | 2023-05-03 21:39:35 +0800 |
|---|---|---|
| committer | Luiz Augusto von Dentz <luiz.von.dentz@intel.com> | 2023-05-19 15:37:45 -0700 |
| commit | 2910431ab0e500dfc5df12299bb15eef0f30b43e (patch) | |
| tree | 0e8602d8977512314b7d7780f3d119c1df38675f /net/bluetooth/hci_conn.c | |
| parent | ca1fd42e7dbfcb34890ffbf1f2f4b356776dab6f (diff) | |
Bluetooth: Refcnt drop must be placed last in hci_conn_unlink
If hci_conn_put(conn->parent) reduces conn->parent's reference count to
zero, it can immediately deallocate conn->parent. At the same time,
conn->link->list has its head in conn->parent, causing use-after-free
problems in the latter list_del_rcu(&conn->link->list).
This problem can be easily solved by reordering the two operations,
i.e., first performing the list removal with list_del_rcu and then
decreasing the refcnt with hci_conn_put.
Reported-by: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Closes: https://lore.kernel.org/linux-bluetooth/CABBYNZ+1kce8_RJrLNOXd_8=Mdpb=2bx4Nto-hFORk=qiOkoCg@mail.gmail.com/
Fixes: 06149746e720 ("Bluetooth: hci_conn: Add support for linking multiple hcon")
Signed-off-by: Ruihan Li <lrh2000@pku.edu.cn>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Diffstat (limited to 'net/bluetooth/hci_conn.c')
| -rw-r--r-- | net/bluetooth/hci_conn.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c index 70e1655a9df6..44d0643fc681 100644 --- a/net/bluetooth/hci_conn.c +++ b/net/bluetooth/hci_conn.c @@ -1102,12 +1102,12 @@ static void hci_conn_unlink(struct hci_conn *conn) if (!conn->link) return; - hci_conn_put(conn->parent); - conn->parent = NULL; - list_del_rcu(&conn->link->list); synchronize_rcu(); + hci_conn_put(conn->parent); + conn->parent = NULL; + kfree(conn->link); conn->link = NULL; } |