UBUNTU-CVE-2025-68304
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_core: lookup hci_conn on RX path on protocol side The hdev lock/lookup/unlock/use pattern in the packet RX path doesn't ensure hci_conn* is not concurrently modified/deleted. This locking appears to be leftover from before conn_hash started using RCU commit bf4c63252490b ("Bluetooth: convert conn hash to RCU") and not clear if it had purpose since then. Currently, there are code paths that delete hci_conn* from elsewhere than the ordered hdev->workqueue where the RX work runs in. E.g. commit 5af1f84ed13a ("Bluetooth: hci_sync: Fix UAF on hci_abort_conn_sync") introduced some of these, and there probably were a few others before it. It's better to do the locking so that even if these run concurrently no UAF is possible. Move the lookup of hci_conn and associated socket-specific conn to protocol recv handlers, and do them within a single critical section to cover hci_conn* usage and lookup. syzkaller has reported a crash that appears to be this issue: [Task hdev->workqueue] [Task 2] hci_disconnect_all_sync l2cap_recv_acldata(hcon) hci_conn_get(hcon) hci_abort_conn_sync(hcon) hci_dev_lock hci_dev_lock hci_conn_del(hcon) v-------------------------------- hci_dev_unlock hci_conn_put(hcon) conn = hcon->l2cap_data (UAF)
02 / AFFECTED SOFTWARE
Affected packages
8 explicit affected versions
10 explicit affected versions
7 explicit affected versions
1 explicit affected versions
2 explicit affected versions
11 explicit affected versions
50 explicit affected versions
6 explicit affected versions
5 explicit affected versions
10 explicit affected versions
12 explicit affected versions
19 explicit affected versions
10 explicit affected versions
6 explicit affected versions
24 explicit affected versions
39 explicit affected versions
26 explicit affected versions
7 explicit affected versions
42 explicit affected versions
13 explicit affected versions
46 explicit affected versions
35 explicit affected versions
18 explicit affected versions
48 explicit affected versions
13 explicit affected versions
4 explicit affected versions
23 explicit affected versions
37 explicit affected versions
55 explicit affected versions
1 explicit affected versions
21 explicit affected versions
9 explicit affected versions
16 explicit affected versions
10 explicit affected versions
13 explicit affected versions
51 explicit affected versions
8 explicit affected versions
7 explicit affected versions
12 explicit affected versions
11 explicit affected versions
7 explicit affected versions
12 explicit affected versions
14 explicit affected versions
10 explicit affected versions
1 explicit affected versions
23 explicit affected versions
7 explicit affected versions
19 explicit affected versions
12 explicit affected versions
2 explicit affected versions
12 explicit affected versions
44 explicit affected versions
16 explicit affected versions
10 explicit affected versions
29 explicit affected versions
10 explicit affected versions
37 explicit affected versions
10 explicit affected versions
2 explicit affected versions
13 explicit affected versions
42 explicit affected versions
3 explicit affected versions
10 explicit affected versions
11 explicit affected versions
26 explicit affected versions
12 explicit affected versions
13 explicit affected versions
29 explicit affected versions
13 explicit affected versions
12 explicit affected versions
43 explicit affected versions
43 explicit affected versions
1 explicit affected versions
33 explicit affected versions
23 explicit affected versions
10 explicit affected versions
22 explicit affected versions
11 explicit affected versions
5 explicit affected versions
12 explicit affected versions
12 explicit affected versions
7 explicit affected versions
9 explicit affected versions
5 explicit affected versions
10 explicit affected versions
26 explicit affected versions
42 explicit affected versions
37 explicit affected versions
48 explicit affected versions
11 explicit affected versions
2 explicit affected versions
13 explicit affected versions
48 explicit affected versions
16 explicit affected versions
53 explicit affected versions
3 explicit affected versions
7 explicit affected versions
8 explicit affected versions
8 explicit affected versions
51 explicit affected versions
9 explicit affected versions
18 explicit affected versions
43 explicit affected versions
12 explicit affected versions
3 explicit affected versions
27 explicit affected versions
45 explicit affected versions
42 explicit affected versions
21 explicit affected versions
7 explicit affected versions
49 explicit affected versions
13 explicit affected versions
13 explicit affected versions
7 explicit affected versions
8 explicit affected versions
10 explicit affected versions
12 explicit affected versions
9 explicit affected versions
44 explicit affected versions
16 explicit affected versions
3 explicit affected versions
13 explicit affected versions
26 explicit affected versions
45 explicit affected versions
37 explicit affected versions
53 explicit affected versions
14 explicit affected versions
38 explicit affected versions
9 explicit affected versions
10 explicit affected versions
11 explicit affected versions
8 explicit affected versions
8 explicit affected versions
7 explicit affected versions
4 explicit affected versions
1 explicit affected versions
1 explicit affected versions
13 explicit affected versions
43 explicit affected versions
8 explicit affected versions
5 explicit affected versions
10 explicit affected versions
48 explicit affected versions
14 explicit affected versions
4 explicit affected versions
78 explicit affected versions
7 explicit affected versions
11 explicit affected versions
1 explicit affected versions
22 explicit affected versions
41 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_core: lookup hci_conn on RX path on protocol side The hdev lock/lookup/unlock/use pattern in the packet RX path doesn't ensure hci_conn* is not concurrently modified/deleted. This locking appears to be leftover from before conn_hash started using RCU commit bf4c63252490b ("Bluetooth: convert conn hash to RCU") and not clear if it had purpose since then. Currently, there are code paths that delete hci_conn* from elsewhere than the ordered hdev->workqueue where the RX work runs in. E.g. commit 5af1f84ed13a ("Bluetooth: hci_sync: Fix UAF on hci_abort_conn_sync") introduced some of these, and there probably were a few others before it. It's better to do the locking so that even if these run concurrently no UAF is possible. Move the lookup of hci_conn and associated socket-specific conn to protocol recv handlers, and do them within a single critical section to cover hci_conn* usage and lookup. syzkaller has reported a crash that appears to be this issue: [Task hdev->workqueue] [Task 2] hci_disconnect_all_sync l2cap_recv_acldata(hcon) hci_conn_get(hcon) hci_abort_conn_sync(hcon) hci_dev_lock hci_dev_lock hci_conn_del(hcon) v-------------------------------- hci_dev_unlock hci_conn_put(hcon) conn = hcon->l2cap_data (UAF)
05 / REFERENCES
Further evidence
- https://git.kernel.org/linus/79a2d4678ba90bdba577dc3af88cc900d6dcd5ee
- https://git.kernel.org/stable/c/79a2d4678ba90bdba577dc3af88cc900d6dcd5ee
- https://git.kernel.org/stable/c/ec74cdf77310c43b01b83ee898a9bd4b4b0b8e93
- https://ubuntu.com/security/CVE-2025-68304
- https://ubuntu.com/security/notices/USN-8094-1
- https://ubuntu.com/security/notices/USN-8094-2
- https://ubuntu.com/security/notices/USN-8094-3
- https://ubuntu.com/security/notices/USN-8094-4
- https://ubuntu.com/security/notices/USN-8094-5
- https://ubuntu.com/security/notices/USN-8152-1
- https://www.cve.org/CVERecord?id=CVE-2025-68304