CVE-2026-98297Bluetooth: hci_core: Fix queuing tx_work after workqueue is drained

Official description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_core: Fix queuing tx_work after workqueue is drained hci_send_acl(), hci_send_sco() and hci_send_iso() queue hdev->tx_work unconditionally. They can run from the L2CAP/SCO/ISO socket send path while hci_dev_close_sync() is draining hdev->workqueue (HCIDEVDOWN racing with a socket write). Since that queue_work() is not chained work from the tx_work worker itself, __queue_work() sees the queue marked __WQ_DRAINING, warns "cannot queue %ps on wq %s", and drops the work: WARNING: CPU: 1 PID: 5985 at kernel/workqueue.c:2352 __queue_work Call Trace: queue_work_on l2cap_chan_send l2cap_sock_sendmsg ... hci_dev_close_sync() already sets HCI_CMD_DRAIN_WORKQUEUE before draining, but only hci_cmd_work() and handle_cmd_cnt_and_timer() check it before queuing. Route the tx_work producers through the same guard via a shared hci_sched_tx() helper.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/9943b4c70ad972f368705da8605054f865b08dad
• https://git.kernel.org/stable/c/8010212197d4a3ee714f78ed77048d0b712ff925
• https://git.kernel.org/stable/c/ab0678a0701ac4de499428dc1b321659bb74d272
• https://git.kernel.org/stable/c/e220c1242a643d97102a79f09b7ef3aa31276961
• https://git.kernel.org/stable/c/cbb325bc150e8c0dbce004ac0e5516bcffc0de31
• https://git.kernel.org/stable/c/6610c6fe4b8936c232048e6049bf77c70a6f759c