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CVE-2026-99011

CVE-2026-99011 · Bluetooth: SCO: serialise sco_conn lifetime against sco_recv_scodata()

This page contains facts from public vulnerability sources. Check the original advisory before updating.

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: SCO: serialise sco_conn lifetime against sco_recv_scodata() sco_recv_scodata() upgrades the weak hcon->sco_data back-pointer to a strong reference under hdev->lock: hci_dev_lock(hdev); hcon = hci_conn_hash_lookup_handle(hdev, handle); ... conn = sco_conn_hold_unless_zero(hcon->sco_data); hci_dev_unlock(hdev); but the pointer is cleared from the other side without that lock. When the last sco_conn reference is dropped, sco_conn_free() ran conn->hcon->sco_data = NULL; with no hdev->lock held, so the RX path could read hcon->sco_data and call kref_get_unless_zero() on an sco_conn that was concurrently freed: BUG: KASAN: slab-use-after-free in sco_conn_hold_unless_zero+0xbe/0x160 Write of size 4 by task kworker/u17:0 Workqueue: hci0 hci_rx_work Call Trace: sco_conn_hold_unless_zero+0xbe/0x160 sco_recv_scodata+0x13f/0x490 hci_rx_work+0x3af/0x730 kref_get_unless_zero() only guards against a zero refcount, not against the backing memory already being freed. Give hcon->sco_data an actual reference on the sco_conn it points to, so the object cannot be freed while the pointer is still installed, and only clear and drop it from sco_conn_del(), which runs under hdev->lock (its callers, sco_connect_cfm() and sco_disconn_cfm(), hold it). The reader in sco_recv_scodata() also takes hdev->lock, so the store and the read are now serialised: the RX path either observes NULL or a reference that is guaranteed to stay valid until it drops its own. sco_conn_add() no longer hands its kref_init() reference to the caller as the connection's only reference; that initial reference is the one owned by hcon->sco_data, and callers get their own via sco_conn_hold(). Because the sco_conn can now outlive the socket (the association keeps it alive until the link goes down), the hci_conn can no longer be dropped from sco_conn_free() without regressing socket close: closing a connected SCO socket must still tear the link down. Move hci_conn ownership to the socket instead: __sco_chan_add() takes an hci_conn reference and it is released from sco_chan_del() and sco_sock_destruct(), exactly once. The sco_conn no longer owns an hci_conn reference, so sco_conn_add() stops consuming one and sco_connect() drops the hci_connect_sco() reference on every path; sco_connect_cfm() no longer needs its hci_conn_hold() dance.

Fix available

Published
Updated

Stack: system

Affected products and versions

  • linux

    Versions
    • ≥ e6720779ae612a14ac4ba7fe4fd5b27d900d932c, < b108ea7ebba147465f4158d8133f0e8f013762ed: Affected (git)
    • ≥ e6720779ae612a14ac4ba7fe4fd5b27d900d932c, < 8a98d58f6cfe70d51138cd9ce894e72671d95f8a: Affected (git)
    • ≥ e6720779ae612a14ac4ba7fe4fd5b27d900d932c, < 816fb1590a4c8cf8d05cd076057616be02e276f0: Affected (git)

    Update to 8a98d58f6cfe70d51138cd9ce894e72671d95f8a

  • linux

    Versions
    • 6.13: Affected
    • ≥ 0, < 6.13: Not affected (semver)
    • ≥ 6.18.57, ≤ 6.18.*: Not affected (semver)
    • ≥ 7.2.11, ≤ 7.2.*: Not affected (semver)
    • ≥ 7.3: Not affected (original_commit_for_fix)

    No fix published

  • linux Debian:14

    Versions
    • 6.12.100-1
    • 6.12.101-1
    • 6.12.105-1
    • 6.12.107-1
    • 6.12.111-1
    • 6.12.113-1
    • 6.12.38-1
    • 6.12.41-1
    • 6.12.43-1
    • 6.12.43-1~bpo12+1
    • 6.12.48-1
    • 6.12.57-1
    • 6.12.57-1~bpo12+1
    • 6.12.63-1
    • 6.12.63-1~bpo12+1
    • 6.12.69-1
    • 6.12.69-1~bpo12+1
    • 6.12.73-1
    • 6.12.73-1~bpo12+1
    • 6.12.74-1
    • 6.12.74-2
    • 6.12.74-2~bpo12+1
    • 6.12.85-1
    • 6.12.85-1~bpo12+1
    • 6.12.86-1
    • 6.12.86-1~bpo12+1
    • 6.12.88-1
    • 6.12.88-1~bpo12+1
    • 6.12.90-1
    • 6.12.90-1~bpo12+1
    • 6.12.90-2
    • 6.12.90-2~bpo12+1
    • 6.12.94-1
    • 6.12.94-1~bpo12+1
    • 6.12.95-1
    • 6.12.95-1~bpo12+1
    • 6.12.96-1
    • 6.13.10-1~exp1
    • 6.13.11-1~exp1
    • 6.13.2-1~exp1
    • 6.13.3-1~exp1
    • 6.13.4-1~exp1
    • 6.13.5-1~exp1
    • 6.13.6-1~exp1
    • 6.13.7-1~exp1
    • 6.13.8-1~exp1
    • 6.13.9-1~exp1
    • 6.13~rc6-1~exp1
    • 6.13~rc7-1~exp1
    • 6.14.3-1~exp1
    • 6.14.5-1~exp1
    • 6.14.6-1~exp1
    • 6.15-1~exp1
    • 6.15.1-1~exp1
    • 6.15.2-1~exp1
    • 6.15.3-1~exp1
    • 6.15.4-1~exp1
    • 6.15.5-1~exp1
    • 6.15.6-1~exp1
    • 6.15~rc7-1~exp1
    • 6.16-1~exp1
    • 6.16.1-1~exp1
    • 6.16.10-1
    • 6.16.11-1
    • 6.16.12-1
    • 6.16.12-1~bpo13+1
    • 6.16.12-2
    • 6.16.3-1
    • 6.16.3-1~bpo13+1
    • 6.16.5-1
    • 6.16.6-1
    • 6.16.7-1
    • 6.16.8-1
    • 6.16.9-1
    • 6.16~rc7-1~exp1
    • 6.17.10-1
    • 6.17.11-1
    • 6.17.12-1
    • 6.17.13-1
    • 6.17.13-1~bpo13+1
    • 6.17.2-1~exp1
    • 6.17.5-1~exp1
    • 6.17.6-1
    • 6.17.7-1
    • 6.17.7-2
    • 6.17.8-1
    • 6.17.8-1~bpo13+1
    • 6.17.9-1
    • 6.18.1-1~exp1
    • 6.18.10-1
    • 6.18.12-1
    • 6.18.12-1~bpo13+1
    • 6.18.13-1
    • 6.18.14-1
    • 6.18.15-1
    • 6.18.15-1~bpo13+1
    • 6.18.2-1~exp1
    • 6.18.3-1
    • 6.18.5-1
    • 6.18.5-1~bpo13+1
    • 6.18.8-1
    • 6.18.9-1
    • 6.18.9-1~bpo13+1
    • 6.18~rc4-1~exp1
    • 6.18~rc4-1~exp2
    • 6.18~rc5-1~exp1
    • 6.18~rc6-1~exp1
    • 6.18~rc7-1~exp1
    • 6.19-1~exp1
    • 6.19.10-1
    • 6.19.10-1~bpo13+1
    • 6.19.11-1
    • 6.19.11-1~bpo13+1
    • 6.19.12-1
    • 6.19.13-1
    • 6.19.13-1~bpo13+1
    • 6.19.14-1
    • 6.19.14-1~bpo13+1
    • 6.19.2-1~exp1
    • 6.19.3-1~exp1
    • 6.19.4-1~exp1
    • 6.19.5-1~exp1
    • 6.19.6-1
    • 6.19.6-2
    • 6.19.6-2~bpo13+1
    • 6.19.8-1
    • 6.19.8-1~bpo13+1
    • 6.19~rc4-1~exp1
    • 6.19~rc5-1~exp1
    • 6.19~rc6-1~exp1
    • 6.19~rc7-1~exp1
    • 6.19~rc8-1~exp1
    • 7.0-1~exp1
    • 7.0.1-1~exp1
    • 7.0.10-1
    • 7.0.10-1~bpo13+1
    • 7.0.12-1
    • 7.0.12-2
    • 7.0.12-2~bpo13+1
    • 7.0.13-1
    • 7.0.13-1~bpo13+1
    • 7.0.14-1
    • 7.0.3-1
    • 7.0.4-1
    • 7.0.4-1~bpo13+1
    • 7.0.7-1
    • 7.0.7-1~bpo13+1
    • 7.0.9-1
    • 7.0.9-1~bpo13+1
    • 7.1.1-1~exp1
    • 7.1.10-1
    • 7.1.12-1
    • 7.1.13-1
    • 7.1.13-1~bpo13+1
    • 7.1.2-1~exp1
    • 7.1.3-1
    • 7.1.3-1+sunvdc
    • 7.1.3-1~bpo13+1
    • 7.1.4-1
    • 7.1.5-1
    • 7.1.6-1
    • 7.1.7-1
    • 7.1.7-1~bpo13+1
    • 7.1.8-1
    • 7.1.8-1~bpo13+1
    • 7.1.8-2
    • 7.1.9-1
    • 7.1.9-1+sparc64
    • 7.1~rc2-1~exp1
    • 7.1~rc3-1~exp1
    • 7.1~rc4-1~exp1
    • 7.1~rc4-1~exp2
    • 7.1~rc5-1~exp1
    • 7.1~rc7-1~exp1
    • 7.2.10-1
    • 7.2.2-1~exp1
    • 7.2.3-1~exp1
    • 7.2.6-1
    • 7.2.6-1~bpo13+1
    • 7.2.7-1
    • 7.2.8-1
    • 7.2.9-1
    • 7.2.9-1~bpo13+1
    • 7.2~rc3-1~exp1
    • 7.2~rc5-1~exp1
    • 7.2~rc7-1~exp1
    Affected ranges
    • ECOSYSTEM: < 7.2.11-1

    Update to 7.2.11-1

Original sources

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