Skip to content
CVE PROGRAM SOURCE RECORD7.8 High

CVE-2026-43023

Bluetooth: SCO: fix race conditions in sco_sock_connect()

Read JSON ↗CVE.org ↗
Status
Published
Published
Updated
Assigning organization
Linux

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: SCO: fix race conditions in sco_sock_connect() sco_sock_connect() checks sk_state and sk_type without holding the socket lock. Two concurrent connect() syscalls on the same socket can both pass the check and enter sco_connect(), leading to use-after-free. The buggy scenario involves three participants and was confirmed with additional logging instrumentation: Thread A (connect): HCI disconnect: Thread B (connect): sco_sock_connect(sk) sco_sock_connect(sk) sk_state==BT_OPEN sk_state==BT_OPEN (pass, no lock) (pass, no lock) sco_connect(sk): sco_connect(sk): hci_dev_lock hci_dev_lock hci_connect_sco <- blocked -> hcon1 sco_conn_add->conn1 lock_sock(sk) sco_chan_add: conn1->sk = sk sk->conn = conn1 sk_state=BT_CONNECT release_sock hci_dev_unlock hci_dev_lock sco_conn_del: lock_sock(sk) sco_chan_del: sk->conn=NULL conn1->sk=NULL sk_state= BT_CLOSED SOCK_ZAPPED release_sock hci_dev_unlock (unblocked) hci_connect_sco -> hcon2 sco_conn_add -> conn2 lock_sock(sk) sco_chan_add: sk->conn=conn2 sk_state= BT_CONNECT // zombie sk! release_sock hci_dev_unlock Thread B revives a BT_CLOSED + SOCK_ZAPPED socket back to BT_CONNECT. Subsequent cleanup triggers double sock_put() and use-after-free. Meanwhile conn1 is leaked as it was orphaned when sco_conn_del() cleared the association. Fix this by: - Moving lock_sock() before the sk_state/sk_type checks in sco_sock_connect() to serialize concurrent connect attempts - Fixing the sk_type != SOCK_SEQPACKET check to actually return the error instead of just assigning it - Adding a state re-check in sco_connect() after lock_sock() to catch state changes during the window between the locks - Adding sco_pi(sk)->conn check in sco_chan_add() to prevent double-attach of a socket to multiple connections - Adding hci_conn_drop() on sco_chan_add failure to prevent HCI connection leaks

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Linux Linux

Default version status: unaffected

  • 70a13b1e25fef37c87c8a1228ddb8900efbca7cf to < dabf22269242e2f2bf44c43fcdc2fa763df7f9ccaffected
  • 9a8ec9e8ebb5a7c0cfbce2d6b4a6b67b2b78e8f3 to < adb90cd0f9f7a8d438fcb93354040fbafc5ae2a0affected
  • 9a8ec9e8ebb5a7c0cfbce2d6b4a6b67b2b78e8f3 to < 7e296ffdab5bdab718dff7c14288fdcb9154fa27affected
  • 9a8ec9e8ebb5a7c0cfbce2d6b4a6b67b2b78e8f3 to < 98c8d3bfdaa657d8f472dbbebd7ea8cd816d8a8daffected
  • 9a8ec9e8ebb5a7c0cfbce2d6b4a6b67b2b78e8f3 to < d002bd11024bd231bcb606877e33951ffb7bed14affected
  • 9a8ec9e8ebb5a7c0cfbce2d6b4a6b67b2b78e8f3 to < 8a5b0135d4a5d9683203a3d9a12a711ccec5936baffected
  • 6.1.109 to < 6.1.168affected

Linux Linux

Default version status: affected

  • 6.3affected
  • 0 to < 6.3unaffected
  • 6.1.168 to ≤ 6.1.*unaffected
  • 6.6.134 to ≤ 6.6.*unaffected
  • 6.12.81 to ≤ 6.12.*unaffected
  • 6.18.22 to ≤ 6.18.*unaffected
  • 6.19.12 to ≤ 6.19.*unaffected
  • 7.0 to ≤ *unaffected

References