CVE-2026-64557 is a vulnerability in Linux Kernel
Published on July 29, 2026
Bluetooth: L2CAP: Fix use-after-free in l2cap_sock_new_connection_cb()
In 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.
Products Associated with CVE-2026-64557
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Affected Versions
Linux:- Version 8ffb929098a56939ac71509302eeab5b207bf262 and below b39298044e5534612511a2ff5de03ba5f6e7a820 is affected.
- Version 8ffb929098a56939ac71509302eeab5b207bf262 and below 8c37e4338c801ebb8cee52436c01c41e009f6e87 is affected.
- Version 8ffb929098a56939ac71509302eeab5b207bf262 and below 84e718b6a814edc84159361f9f454a4e92ae91ae is affected.
- Version 8ffb929098a56939ac71509302eeab5b207bf262 and below 36da806f7fbaee56ad9e81859deec203f9728700 is affected.
- Version 8ffb929098a56939ac71509302eeab5b207bf262 and below 733e76e74e406c1d1ddc7369420dd8a47f48bb8a is affected.
- Version 8ffb929098a56939ac71509302eeab5b207bf262 and below 6fef032af0092ed5ccb767239a9ac1bc38c08a40 is affected.
- Version 3.13 is affected.
- Before 3.13 is unaffected.
- Version 6.1.178, <= 6.1.* is unaffected.
- Version 6.6.145, <= 6.6.* is unaffected.
- Version 6.12.97, <= 6.12.* is unaffected.
- Version 6.18.40, <= 6.18.* is unaffected.
- Version 7.1.5, <= 7.1.* is unaffected.
- Version 7.2-rc3, <= * is unaffected.