CVE-2026-23461 (GCVE-0-2026-23461)

Vulnerability from cvelistv5 – Published: 2026-04-03 15:15 – Updated: 2026-04-27 14:02
VLAI?
Title
Bluetooth: L2CAP: Fix use-after-free in l2cap_unregister_user
Summary
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Fix use-after-free in l2cap_unregister_user After commit ab4eedb790ca ("Bluetooth: L2CAP: Fix corrupted list in hci_chan_del"), l2cap_conn_del() uses conn->lock to protect access to conn->users. However, l2cap_register_user() and l2cap_unregister_user() don't use conn->lock, creating a race condition where these functions can access conn->users and conn->hchan concurrently with l2cap_conn_del(). This can lead to use-after-free and list corruption bugs, as reported by syzbot. Fix this by changing l2cap_register_user() and l2cap_unregister_user() to use conn->lock instead of hci_dev_lock(), ensuring consistent locking for the l2cap_conn structure.
Severity ?
8.8 (High)
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: efc30877bd4bc85fefe98d80af60fafc86e5775e , < 11a87dd5df428a4b79a84d2790cac7f3c73f1f0d (git)
Affected: f87271d21dd4ee83857ca11b94e7b4952749bbae , < c22a5e659959eb77c2fbb58a5adfaf3c3dab7abf (git)
Affected: ab4eedb790cae44313759b50fe47da285e2519d5 , < da3000cbe4851458a22be38bb18c0689c39fdd5f (git)
Affected: ab4eedb790cae44313759b50fe47da285e2519d5 , < 71030f3b3015a412133a805ff47970cdcf30c2b8 (git)
Affected: ab4eedb790cae44313759b50fe47da285e2519d5 , < 752a6c9596dd25efd6978a73ff21f3b592668f4a (git)
Affected: 18ab6b6078fa8191ca30a3065d57bf35d5635761 (git)
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    Linux Linux Affected: 6.14
Unaffected: 0 , < 6.14 (semver)
Unaffected: 6.6.130 , ≤ 6.6.* (semver)
Unaffected: 6.12.78 , ≤ 6.12.* (semver)
Unaffected: 6.18.20 , ≤ 6.18.* (semver)
Unaffected: 6.19.10 , ≤ 6.19.* (semver)
Unaffected: 7.0 , ≤ * (original_commit_for_fix)
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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



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