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authorRuihan Li <[email protected]>2023-05-03 21:39:34 +0800
committerLuiz Augusto von Dentz <[email protected]>2023-05-19 15:37:45 -0700
commitca1fd42e7dbfcb34890ffbf1f2f4b356776dab6f (patch)
treed9d20f006026eff3205997d33ffe564d3db4c893
parent9025944fddfed5966c8f102f1fe921ab3aee2c12 (diff)
Bluetooth: Fix potential double free caused by hci_conn_unlink
The hci_conn_unlink function is being called by hci_conn_del, which means it should not call hci_conn_del with the input parameter conn again. If it does, conn may have already been released when hci_conn_unlink returns, leading to potential UAF and double-free issues. This patch resolves the problem by modifying hci_conn_unlink to release only conn's child links when necessary, but never release conn itself. Reported-by: [email protected] Closes: https://lore.kernel.org/linux-bluetooth/[email protected]/ Fixes: 06149746e720 ("Bluetooth: hci_conn: Add support for linking multiple hcon") Signed-off-by: Ruihan Li <[email protected]> Signed-off-by: Luiz Augusto von Dentz <[email protected]> Reported-by: [email protected] Reported-by: Luiz Augusto von Dentz <[email protected]> Reported-by: [email protected]
-rw-r--r--net/bluetooth/hci_conn.c21
1 files changed, 12 insertions, 9 deletions
diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index 640b951bf40a..70e1655a9df6 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -1083,8 +1083,18 @@ static void hci_conn_unlink(struct hci_conn *conn)
if (!conn->parent) {
struct hci_link *link, *t;
- list_for_each_entry_safe(link, t, &conn->link_list, list)
- hci_conn_unlink(link->conn);
+ list_for_each_entry_safe(link, t, &conn->link_list, list) {
+ struct hci_conn *child = link->conn;
+
+ hci_conn_unlink(child);
+
+ /* Due to race, SCO connection might be not established
+ * yet at this point. Delete it now, otherwise it is
+ * possible for it to be stuck and can't be deleted.
+ */
+ if (child->handle == HCI_CONN_HANDLE_UNSET)
+ hci_conn_del(child);
+ }
return;
}
@@ -1100,13 +1110,6 @@ static void hci_conn_unlink(struct hci_conn *conn)
kfree(conn->link);
conn->link = NULL;
-
- /* Due to race, SCO connection might be not established
- * yet at this point. Delete it now, otherwise it is
- * possible for it to be stuck and can't be deleted.
- */
- if (conn->handle == HCI_CONN_HANDLE_UNSET)
- hci_conn_del(conn);
}
int hci_conn_del(struct hci_conn *conn)