CVE-2026-53357
Bluetooth: fix UAF in l2cap_sock_cleanup_listen() vs l2cap_conn_del()
Description
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: fix UAF in l2cap_sock_cleanup_listen() vs l2cap_conn_del() bt_accept_dequeue() unlinks a not-yet-accepted child from the parent accept queue and release_sock()s it before returning, so the returned sk has no caller reference and is unlocked. l2cap_sock_cleanup_listen() walks these children on listening-socket close. A concurrent HCI disconnect drives hci_rx_work -> l2cap_conn_del() which runs l2cap_chan_del() + l2cap_sock_kill() and frees the child sk and its l2cap_chan; cleanup_listen() then uses both: BUG: KASAN: slab-use-after-free in l2cap_sock_kill l2cap_sock_kill / l2cap_sock_cleanup_listen / __x64_sys_close Freed by: l2cap_conn_del -> l2cap_sock_close_cb -> l2cap_sock_kill This is distinct from the two fixes already in this area: commit e83f5e24da741 ("Bluetooth: serialize accept_q access") serialises the accept_q list/poll and takes temporary refs inside bt_accept_dequeue(), and CVE-2025-39860 serialises the userspace close()/accept() race by calling cleanup_listen() under lock_sock() in l2cap_sock_release(). Neither covers l2cap_conn_del() running from hci_rx_work, so this UAF still reproduces on current bluetooth/master. Take the reference at the source: bt_accept_dequeue() does sock_hold() while sk is still locked, before release_sock(); callers sock_put(). cleanup_listen() pins the chan with l2cap_chan_hold_unless_zero() under a brief child sk lock (serialising vs l2cap_sock_teardown_cb()), drops it before l2cap_chan_lock(), and skips a duplicate l2cap_sock_kill() on SOCK_DEAD. conn->lock is not taken here: cleanup_listen() runs under the parent sk lock and that would invert conn->lock -> chan->lock -> sk_lock (lockdep). KASAN/SMP: an unprivileged listen/close vs HCI-disconnect race produced 12 use-after-free reports per run before this change; 0, and no lockdep report, over 1600+ raced iterations after it on bluetooth/master.
INFO
Published Date :
July 2, 2026, 3:17 p.m.
Last Modified :
July 22, 2026, 7:06 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
Solution
- Apply the patch to the Linux kernel.
- Ensure proper socket reference counting.
- Manage child socket references before release.
- Synchronize socket cleanup with disconnect events.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-53357.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-53357 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-53357
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-53357 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-53357 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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Initial Analysis by [email protected]
Jul. 22, 2026
Action Type Old Value New Value Added CWE CWE-416 Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.16 up to (excluding) 6.1.175 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.12.92 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.13 up to (excluding) 6.18.34 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.19 up to (excluding) 7.0.11 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.2 up to (excluding) 6.6.142 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.11 up to (excluding) 5.15.210 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.7 up to (excluding) 5.10.259 Added Reference Type kernel.org: https://git.kernel.org/stable/c/407217734835d21d4e0105ebf347860dc1806f88 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/5d86d2f1b4d9a508c441d3e45277ae1a73cfed57 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/751de6ec671fe75ad9cf65a0638d2a06b6a5984d Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/7eebd4c2c86f573af87ff165d08a83432eb0b919 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/87c543e2f78d0871f271df92dab98901bbd5b6f5 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/a5ca86a6097a8b030ca3226cd300b17ed330f966 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/ab1513597c6cf17cd1ad2a21e3b045421b48e022 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/added1213395071470a900cc845a042fb51882a6 Types: Patch -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 18, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 02, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '15f02b91056253e8cdc592888f431da0731337b8', 'lessThan': '751de6ec671fe75ad9cf65a0638d2a06b6a5984d', 'versionType': 'git'}, {'status': 'affected', 'version': '15f02b91056253e8cdc592888f431da0731337b8', 'lessThan': '407217734835d21d4e0105ebf347860dc1806f88', 'versionType': 'git'}, {'status': 'affected', 'version': '15f02b91056253e8cdc592888f431da0731337b8', 'lessThan': '7eebd4c2c86f573af87ff165d08a83432eb0b919', 'versionType': 'git'}, {'status': 'affected', 'version': '15f02b91056253e8cdc592888f431da0731337b8', 'lessThan': '5d86d2f1b4d9a508c441d3e45277ae1a73cfed57', 'versionType': 'git'}, {'status': 'affected', 'version': '15f02b91056253e8cdc592888f431da0731337b8', 'lessThan': '87c543e2f78d0871f271df92dab98901bbd5b6f5', 'versionType': 'git'}, {'status': 'affected', 'version': '15f02b91056253e8cdc592888f431da0731337b8', 'lessThan': 'added1213395071470a900cc845a042fb51882a6', 'versionType': 'git'}, {'status': 'affected', 'version': '15f02b91056253e8cdc592888f431da0731337b8', 'lessThan': 'a5ca86a6097a8b030ca3226cd300b17ed330f966', 'versionType': 'git'}, {'status': 'affected', 'version': '15f02b91056253e8cdc592888f431da0731337b8', 'lessThan': 'ab1513597c6cf17cd1ad2a21e3b045421b48e022', 'versionType': 'git'}], 'programFiles': ['net/bluetooth/af_bluetooth.c', 'net/bluetooth/iso.c', 'net/bluetooth/l2cap_sock.c', 'net/bluetooth/rfcomm/sock.c', 'net/bluetooth/sco.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '5.7'}, {'status': 'unaffected', 'version': '0', 'lessThan': '5.7', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '5.10.259', 'versionType': 'semver', 'lessThanOrEqual': '5.10.*'}, {'status': 'unaffected', 'version': '5.15.210', 'versionType': 'semver', 'lessThanOrEqual': '5.15.*'}, {'status': 'unaffected', 'version': '6.1.175', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.142', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.92', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.34', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.0.11', 'versionType': 'semver', 'lessThanOrEqual': '7.0.*'}, {'status': 'unaffected', 'version': '7.1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['net/bluetooth/af_bluetooth.c', 'net/bluetooth/iso.c', 'net/bluetooth/l2cap_sock.c', 'net/bluetooth/rfcomm/sock.c', 'net/bluetooth/sco.c'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: Bluetooth: fix UAF in l2cap_sock_cleanup_listen() vs l2cap_conn_del() bt_accept_dequeue() unlinks a not-yet-accepted child from the parent accept queue and release_sock()s it before returning, so the returned sk has no caller reference and is unlocked. l2cap_sock_cleanup_listen() walks these children on listening-socket close. A concurrent HCI disconnect drives hci_rx_work -> l2cap_conn_del() which runs l2cap_chan_del() + l2cap_sock_kill() and frees the child sk and its l2cap_chan; cleanup_listen() then uses both: BUG: KASAN: slab-use-after-free in l2cap_sock_kill l2cap_sock_kill / l2cap_sock_cleanup_listen / __x64_sys_close Freed by: l2cap_conn_del -> l2cap_sock_close_cb -> l2cap_sock_kill This is distinct from the two fixes already in this area: commit e83f5e24da741 ("Bluetooth: serialize accept_q access") serialises the accept_q list/poll and takes temporary refs inside bt_accept_dequeue(), and CVE-2025-39860 serialises the userspace close()/accept() race by calling cleanup_listen() under lock_sock() in l2cap_sock_release(). Neither covers l2cap_conn_del() running from hci_rx_work, so this UAF still reproduces on current bluetooth/master. Take the reference at the source: bt_accept_dequeue() does sock_hold() while sk is still locked, before release_sock(); callers sock_put(). cleanup_listen() pins the chan with l2cap_chan_hold_unless_zero() under a brief child sk lock (serialising vs l2cap_sock_teardown_cb()), drops it before l2cap_chan_lock(), and skips a duplicate l2cap_sock_kill() on SOCK_DEAD. conn->lock is not taken here: cleanup_listen() runs under the parent sk lock and that would invert conn->lock -> chan->lock -> sk_lock (lockdep). KASAN/SMP: an unprivileged listen/close vs HCI-disconnect race produced 12 use-after-free reports per run before this change; 0, and no lockdep report, over 1600+ raced iterations after it on bluetooth/master. Added Reference https://git.kernel.org/stable/c/407217734835d21d4e0105ebf347860dc1806f88 Added Reference https://git.kernel.org/stable/c/5d86d2f1b4d9a508c441d3e45277ae1a73cfed57 Added Reference https://git.kernel.org/stable/c/751de6ec671fe75ad9cf65a0638d2a06b6a5984d Added Reference https://git.kernel.org/stable/c/7eebd4c2c86f573af87ff165d08a83432eb0b919 Added Reference https://git.kernel.org/stable/c/87c543e2f78d0871f271df92dab98901bbd5b6f5 Added Reference https://git.kernel.org/stable/c/a5ca86a6097a8b030ca3226cd300b17ed330f966 Added Reference https://git.kernel.org/stable/c/ab1513597c6cf17cd1ad2a21e3b045421b48e022 Added Reference https://git.kernel.org/stable/c/added1213395071470a900cc845a042fb51882a6