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CVE-2026-90091— Bluetooth: L2CAP: fix race l2cap_sock_cleanup_listen() vs. put_chan

Quick assessment

Affected
Linux Linux
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

在 Linux 内核中，以下漏洞已被修复： Bluetooth：L2CAP：修复 l2cap_sock_cleanup_listen() 与 put_chan 之间的竞态条件 对于未拥有 的 L2CAP socket，读取 的操作可能会与并发的 产生竞态。该情况排除了同时发生的 回调，但在 中对 的访问存在不安全的无锁读取。 [任务 1] [任务 2 (hdev->workqueue)] l2cap_sock_release(parent) l2cap_disconn_cfm l2cap_sock_cleanup_

CVSS 8.0 · High EPSS 0.35% · P27

Affected Version Matrix 20

VendorProduct Version RangeStatus
Linux Linux b39298044e5534612511a2ff5de03ba5f6e7a820< 827de6bd2865b22aaabd554540def3b8a33018ab affected
8c37e4338c801ebb8cee52436c01c41e009f6e87< 7c7ac736b50fa259ed1bdddc18d79523f07c0442 affected
84e718b6a814edc84159361f9f454a4e92ae91ae< 4f8c63fe0097c9f6ea34409f82f79b3894903d91 affected
36da806f7fbaee56ad9e81859deec203f9728700< 61d5ddbd524c715b224cbe7e9f01da4e05098b19 affected
6fef032af0092ed5ccb767239a9ac1bc38c08a40< 32a7bc6e93be36b37fe61f351d312d358195bd61 affected
6fef032af0092ed5ccb767239a9ac1bc38c08a40< 66d6ef18548ae6d7dd452b84115fc82c0a73a4ea affected
733e76e74e406c1d1ddc7369420dd8a47f48bb8a affected
6.1.178< 6.1.188 affected
… +12 more rows
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I. Basic Information for CVE-2026-90091

Vulnerability Information
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Vulnerability Title
Bluetooth: L2CAP: fix race l2cap_sock_cleanup_listen() vs. put_chan
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: fix race l2cap_sock_cleanup_listen() vs. put_chan For L2CAP sockets without owning sk->sk_socket, reading l2cap_pi(sk)->chan may race against concurrent l2cap_sock_kill() -> l2cap_sock_put_chan(). This excludes simultaneous proto_ops callbacks, but access in l2cap_sock_cleanup_listen() has unsafe lockless read. [Task 1] [Task 2 (hdev->workqueue)] l2cap_sock_release(parent) l2cap_disconn_cfm l2cap_sock_cleanup_listen l2cap_conn_del bt_accept_dequeue l2cap_chan_del lock_sock(sk) l2cap_sock_teardown_cb bt_accept_unlink bt_sk(sk)->parent = NULL release_sock(sk) ----------------> lock_sock(sk) parent = /* NULL */ lock_sock(sk) <--------------------- release_sock(sk) sock_set_flag(sk, SOCK_ZAPPED) l2cap_sock_close_cb l2cap_sock_kill(sk) l2cap_sock_put_chan chan = READ l2cap_pi(sk)->chan l2cap_pi(sk)->chan = NULL l2cap_chan_hold_unless_zero l2cap_put_chan(chan) kref_get_unless_zero(&chan->ref) Task 1 may observe NULL which causes null-ptr-deref. Fix the race by taking lock_sock() in l2cap_sock_kill() to synchronize with l2cap_sock_cleanup_listen(). hold_unless_zero() is not needed here, l2cap_pi(sk)->chan owns reference if it is non-NULL. Clarify code comments vs. locking.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Source: CVE Program / CVE List V5
Vulnerability Type
N/A
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
Linux Linux b39298044e5534612511a2ff5de03ba5f6e7a820 ~ 827de6bd2865b22aaabd554540def3b8a33018ab -
Linux Linux 7.2 -

II. Public POCs for CVE-2026-90091

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III. Intelligence Information for CVE-2026-90091

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Patches & Fixes for CVE-2026-90091 (6)

Same Patch Batch · Linux · 2026-09-17 · 600 CVEs total

CVE-2026-92489 9.8 CRITICAL xfrm: Fix skb double-free in xfrm_dev_direct_output()
CVE-2026-90104 9.8 CRITICAL NFSv4.1: zero referring call lists before decoding
CVE-2026-90235 9.8 CRITICAL sunrpc: xprtsock: annotate shared socket callbacks with READ_ONCE/WRITE_ONCE
CVE-2026-90173 9.8 CRITICAL smb: smbdirect: free completion queues with ib_free_cq()
CVE-2026-90151 9.8 CRITICAL NFSv4: remove callback IDR entry on client allocation failure
CVE-2026-90110 9.4 CRITICAL inetpeer: randomize RB-tree node comparison using SipHash
CVE-2026-90413 9.1 CRITICAL IB/isert: reject login PDUs declaring more data than was received
CVE-2026-90414 9.1 CRITICAL IB/isert: reject PDUs declaring more data than was received
CVE-2026-90230 9.1 CRITICAL nvmet: fix heap out-of-bounds read in nvmet_auth_negotiate()
CVE-2026-90256 8.8 HIGH Bluetooth: L2CAP: use proto_lock for l2cap_data to fix l2cap_disconn_ind
CVE-2026-90357 8.8 HIGH wifi: mt76: mt7915: unlink TWT flow if the MCU rejects the agreement
CVE-2026-90286 8.8 HIGH drm/amdgpu/gfx6: Use PFP on the compute queues too
CVE-2026-90381 8.8 HIGH wifi: mt76: fix handling channel context with different bands in mt76_switch_vif_chanctx()
CVE-2026-90380 8.8 HIGH wifi: mt76: mt792x: fix use-after-free in mt76_rx_poll_complete
CVE-2026-90329 8.8 HIGH HID: synchronize input before cleaning up a failed probe
CVE-2026-93042 8.8 HIGH dmaengine: dw-edma: Terminate all descriptors without callbacks
CVE-2026-90162 8.8 HIGH ksmbd: defer publishing granted locks to prevent UAF/double-free race
CVE-2026-90379 8.8 HIGH wifi: mt76: mt7921: Add PCIe AER handler support to prevent system crash
CVE-2026-90367 8.8 HIGH wifi: mt76: mt7996: hold dev->mt76.mutex while disabling tx worker in SER
CVE-2026-90371 8.8 HIGH wifi: mt76: fix RXDMAD_C buffer recycling race

Showing top 20 of 600 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

V. Comments for CVE-2026-90091

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