summaryrefslogtreecommitdiff
path: root/net/bluetooth
diff options
context:
space:
mode:
authorRuihan Li <lrh2000@pku.edu.cn>2023-05-03 16:39:34 +0300
committerLuiz Augusto von Dentz <luiz.von.dentz@intel.com>2023-05-20 01:37:45 +0300
commitca1fd42e7dbfcb34890ffbf1f2f4b356776dab6f (patch)
treed9d20f006026eff3205997d33ffe564d3db4c893 /net/bluetooth
parent9025944fddfed5966c8f102f1fe921ab3aee2c12 (diff)
downloadlinux-ca1fd42e7dbfcb34890ffbf1f2f4b356776dab6f.tar.xz
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: syzbot+690b90b14f14f43f4688@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-bluetooth/000000000000484a8205faafe216@google.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> Reported-by: syzbot+690b90b14f14f43f4688@syzkaller.appspotmail.com Reported-by: Luiz Augusto von Dentz <luiz.dentz@gmail.com> Reported-by: syzbot+8bb72f86fc823817bc5d@syzkaller.appspotmail.com
Diffstat (limited to 'net/bluetooth')
-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)