2021-06-08 19:05:04

by Greg Kroah-Hartman

[permalink] [raw]
Subject: [PATCH 5.10 078/137] Bluetooth: fix the erroneous flush_work() order

From: Lin Ma <[email protected]>

commit 6a137caec23aeb9e036cdfd8a46dd8a366460e5d upstream.

In the cleanup routine for failed initialization of HCI device,
the flush_work(&hdev->rx_work) need to be finished before the
flush_work(&hdev->cmd_work). Otherwise, the hci_rx_work() can
possibly invoke new cmd_work and cause a bug, like double free,
in late processings.

This was assigned CVE-2021-3564.

This patch reorder the flush_work() to fix this bug.

Cc: Marcel Holtmann <[email protected]>
Cc: Johan Hedberg <[email protected]>
Cc: Luiz Augusto von Dentz <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Jakub Kicinski <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Lin Ma <[email protected]>
Signed-off-by: Hao Xiong <[email protected]>
Cc: stable <[email protected]>
Signed-off-by: Marcel Holtmann <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
net/bluetooth/hci_core.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -1602,8 +1602,13 @@ setup_failed:
} else {
/* Init failed, cleanup */
flush_work(&hdev->tx_work);
- flush_work(&hdev->cmd_work);
+
+ /* Since hci_rx_work() is possible to awake new cmd_work
+ * it should be flushed first to avoid unexpected call of
+ * hci_cmd_work()
+ */
flush_work(&hdev->rx_work);
+ flush_work(&hdev->cmd_work);

skb_queue_purge(&hdev->cmd_q);
skb_queue_purge(&hdev->rx_q);