Bluetooth: L2CAP: Fix use-after-free in l2cap_sock_new_connection_cb()

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-64557
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-07-29 09:16:30 UTC
Updated2026-07-30 06:25:59 UTC
DescriptionIn the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Fix use-after-free in l2cap_sock_new_connection_cb() l2cap_sock_new_connection_cb() returned l2cap_pi(sk)->chan after release_sock(parent). Once the parent lock is dropped the newly enqueued child socket sk is reachable via the accept queue, so another task can accept and free it before the callback dereferences sk, resulting in a use-after-free. Rework the ->new_connection() op so the core, rather than the callback, owns the child channel's lifetime. The op now receives a pre-allocated new_chan and returns an errno instead of allocating and returning a channel. l2cap_new_connection() allocates the child channel and links it into the conn list via __l2cap_chan_add() before invoking the callback, so the conn-list reference keeps the channel alive once release_sock(parent) exposes the socket to other tasks. Channel configuration that was duplicated in l2cap_sock_init() and the various new_connection callbacks is consolidated into l2cap_chan_set_defaults(), which now inherits from the parent channel when one is supplied.

Risk And Classification

Primary CVSS: v3.1 8.8 HIGH from 416baaa9-dc9f-4396-8d5f-8c081fb06d67

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS: 0.002360000 probability, percentile 0.147340000 (date 2026-07-31)

VersionSourceTypeScoreSeverityVector
3.1416baaa9-dc9f-4396-8d5f-8c081fb06d67Secondary8.8HIGHCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
3.1CNADECLARED8.8HIGHCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS v3.1 Breakdown

Attack Vector
Adjacent
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected 8ffb929098a56939ac71509302eeab5b207bf262 b39298044e5534612511a2ff5de03ba5f6e7a820 git Not specified
CNA Linux Linux affected 8ffb929098a56939ac71509302eeab5b207bf262 8c37e4338c801ebb8cee52436c01c41e009f6e87 git Not specified
CNA Linux Linux affected 8ffb929098a56939ac71509302eeab5b207bf262 84e718b6a814edc84159361f9f454a4e92ae91ae git Not specified
CNA Linux Linux affected 8ffb929098a56939ac71509302eeab5b207bf262 36da806f7fbaee56ad9e81859deec203f9728700 git Not specified
CNA Linux Linux affected 8ffb929098a56939ac71509302eeab5b207bf262 733e76e74e406c1d1ddc7369420dd8a47f48bb8a git Not specified
CNA Linux Linux affected 8ffb929098a56939ac71509302eeab5b207bf262 6fef032af0092ed5ccb767239a9ac1bc38c08a40 git Not specified
CNA Linux Linux affected 3.13 Not specified
CNA Linux Linux unaffected 3.13 semver Not specified
CNA Linux Linux unaffected 6.1.178 6.1.* semver Not specified
CNA Linux Linux unaffected 6.6.145 6.6.* semver Not specified
CNA Linux Linux unaffected 6.12.97 6.12.* semver Not specified
CNA Linux Linux unaffected 6.18.40 6.18.* semver Not specified
CNA Linux Linux unaffected 7.1.5 7.1.* semver Not specified
CNA Linux Linux unaffected 7.2-rc3 * original_commit_for_fix Not specified

References

ReferenceSourceLinkTags
git.kernel.org/stable/c/36da806f7fbaee56ad9e81859deec203f9728700 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/84e718b6a814edc84159361f9f454a4e92ae91ae 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/6fef032af0092ed5ccb767239a9ac1bc38c08a40 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/733e76e74e406c1d1ddc7369420dd8a47f48bb8a 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/8c37e4338c801ebb8cee52436c01c41e009f6e87 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/b39298044e5534612511a2ff5de03ba5f6e7a820 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
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