From: Pauli Virtanen pav@iki.fi
[ Upstream commit 947ec0d002dce8577b655793dcc6fc78d67b7cb6 ]
hci_send_cmd_sync first sends skb and then tries to clone it. However, the driver may have already freed the skb at that point.
Fix by cloning the sent_cmd cloned just above, instead of the original.
Log: ================================================================ BUG: KASAN: slab-use-after-free in __copy_skb_header+0x1a/0x240 ... Call Trace: .. __skb_clone+0x59/0x2c0 hci_cmd_work+0x3b3/0x3d0 [bluetooth] process_one_work+0x459/0x900 ... Allocated by task 129: ... __alloc_skb+0x1ae/0x220 __hci_cmd_sync_sk+0x44c/0x7a0 [bluetooth] __hci_cmd_sync_status+0x24/0xb0 [bluetooth] set_cig_params_sync+0x778/0x7d0 [bluetooth] ... Freed by task 0: ... kmem_cache_free+0x157/0x3c0 __usb_hcd_giveback_urb+0x11e/0x1e0 usb_giveback_urb_bh+0x1ad/0x2a0 tasklet_action_common.isra.0+0x259/0x4a0 __do_softirq+0x15b/0x5a7 ================================================================
Fixes: 2615fd9a7c25 ("Bluetooth: hci_sync: Fix overwriting request callback") Signed-off-by: Pauli Virtanen pav@iki.fi Signed-off-by: Luiz Augusto von Dentz luiz.von.dentz@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/bluetooth/hci_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c index 88e9d7e0865a2..70f24dc75b596 100644 --- a/net/bluetooth/hci_core.c +++ b/net/bluetooth/hci_core.c @@ -4176,7 +4176,7 @@ static void hci_send_cmd_sync(struct hci_dev *hdev, struct sk_buff *skb) if (hci_req_status_pend(hdev) && !hci_dev_test_and_set_flag(hdev, HCI_CMD_PENDING)) { kfree_skb(hdev->req_skb); - hdev->req_skb = skb_clone(skb, GFP_KERNEL); + hdev->req_skb = skb_clone(hdev->sent_cmd, GFP_KERNEL); }
atomic_dec(&hdev->cmd_cnt);