--- id: CVE-2026-53357 title: |- 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_soc… summary: |- 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_soc… severity: high cvss: 8 cvssVector: 'CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H' published: '2026-07-02' updated: '2026-07-18' source: NVD sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-53357' references: - url: 'https://git.kernel.org/stable/c/407217734835d21d4e0105ebf347860dc1806f88' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/5d86d2f1b4d9a508c441d3e45277ae1a73cfed57' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/751de6ec671fe75ad9cf65a0638d2a06b6a5984d' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/7eebd4c2c86f573af87ff165d08a83432eb0b919' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/87c543e2f78d0871f271df92dab98901bbd5b6f5' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/a5ca86a6097a8b030ca3226cd300b17ed330f966' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/ab1513597c6cf17cd1ad2a21e3b045421b48e022' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/added1213395071470a900cc845a042fb51882a6' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: >- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53357.json - url: 'https://access.redhat.com/security/cve/CVE-2026-53357' - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2496574' - url: 'https://www.cve.org/CVERecord?id=CVE-2026-53357' - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-53357' - url: >- https://lore.kernel.org/linux-cve-announce/2026070234-CVE-2026-53357-18f1@gregkh/T - url: 'https://access.redhat.com/errata/RHSA-2026:76738' - url: 'https://access.redhat.com/errata/RHSA-2026:76739' tags: - nvd - cve.org - csaf - vex - red-hat epss: 0.00332 epssPercentile: 0.26265 ingestedAt: '2026-07-18T13:23:33.223Z' vendor: Linux product: Linux affected: - >- Linux >= 15f02b91056253e8cdc592888f431da0731337b8 < 751de6ec671fe75ad9cf65a0638d2a06b6a5984d - >- Linux >= 15f02b91056253e8cdc592888f431da0731337b8 < 407217734835d21d4e0105ebf347860dc1806f88 - >- Linux >= 15f02b91056253e8cdc592888f431da0731337b8 < 7eebd4c2c86f573af87ff165d08a83432eb0b919 - >- Linux >= 15f02b91056253e8cdc592888f431da0731337b8 < 5d86d2f1b4d9a508c441d3e45277ae1a73cfed57 - >- Linux >= 15f02b91056253e8cdc592888f431da0731337b8 < 87c543e2f78d0871f271df92dab98901bbd5b6f5 - >- Linux >= 15f02b91056253e8cdc592888f431da0731337b8 < added1213395071470a900cc845a042fb51882a6 - >- Linux >= 15f02b91056253e8cdc592888f431da0731337b8 < a5ca86a6097a8b030ca3226cd300b17ed330f966 - >- Linux >= 15f02b91056253e8cdc592888f431da0731337b8 < ab1513597c6cf17cd1ad2a21e3b045421b48e022 - Linux 5.7 ssvc: exploitation: none automatable: 'no' technicalImpact: total timestamp: '2026-10-16T15:28:47.902686Z' patched: - 10base_smtv - enterprise_linux_appstream_v_10 - enterprise_linux_appstream_v_9 - enterprise_linux_baseos_v_10 - enterprise_linux_baseos_v_9 - enterprise_linux_codeready_linux_builder_v_10 - enterprise_linux_codeready_linux_builder_v_9 - enterprise_linux_hidden_v_10 - enterprise_linux_real_time_for_nfv_v_10 - enterprise_linux_real_time_for_nfv_v_9 - enterprise_linux_real_time_v_10 - enterprise_linux_real_time_v_9 cwe: - CWE-366 scores: nvd: 8 vendor: 7 --- ## Overview 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. ## Remediation Refer to the linked advisories for vendor-supplied fixes and affected version ranges. ## Vendor advisories - **RHSA-2026:76738** · Red Hat · fixed in: 10Base-SMTV, Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10), Red Hat Enterprise Linux Hidden (v. 10), Red Hat Enterprise Linux Real Time for NFV (v. 10), … · released 2026-10-08 · [advisory](https://access.redhat.com/errata/RHSA-2026:76738) - **RHSA-2026:76739** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9), Red Hat Enterprise Linux Real Time for NFV (v. 9), Red Hat Enterprise Linux Real Time (v. 9) · released 2026-10-08 · [advisory](https://access.redhat.com/errata/RHSA-2026:76739) - **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · updated 2026-10-26 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53357.json)