CVE-2026-43023

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Source
https://cve.org/CVERecord?id=CVE-2026-43023
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-43023.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2026-43023
Downstream
Related
Published
2026-05-01T14:15:25Z
Modified
2026-08-27T18:26:51Z
Severity
  • 7.8 (High) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
Summary
Bluetooth: SCO: fix race conditions in sco_sock_connect()
Details

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: SCO: fix race conditions in sco_sock_connect()

sco_sock_connect() checks sk_state and sk_type without holding the socket lock. Two concurrent connect() syscalls on the same socket can both pass the check and enter sco_connect(), leading to use-after-free.

The buggy scenario involves three participants and was confirmed with additional logging instrumentation:

Thread A (connect): HCI disconnect: Thread B (connect):

sco_sock_connect(sk) sco_sock_connect(sk) sk_state==BT_OPEN sk_state==BT_OPEN (pass, no lock) (pass, no lock) sco_connect(sk): sco_connect(sk): hci_dev_lock hci_dev_lock hci_connect_sco <- blocked -> hcon1 sco_conn_add->conn1 lock_sock(sk) sco_chan_add: conn1->sk = sk sk->conn = conn1 sk_state=BT_CONNECT release_sock hci_dev_unlock hci_dev_lock sco_conn_del: lock_sock(sk) sco_chan_del: sk->conn=NULL conn1->sk=NULL sk_state= BT_CLOSED SOCK_ZAPPED release_sock hci_dev_unlock (unblocked) hci_connect_sco -> hcon2 sco_conn_add -> conn2 lock_sock(sk) sco_chan_add: sk->conn=conn2 sk_state= BT_CONNECT // zombie sk! release_sock hci_dev_unlock

Thread B revives a BT_CLOSED + SOCK_ZAPPED socket back to BT_CONNECT. Subsequent cleanup triggers double sock_put() and use-after-free. Meanwhile conn1 is leaked as it was orphaned when sco_conn_del() cleared the association.

Fix this by:

  • Moving lock_sock() before the sk_state/sk_type checks in sco_sock_connect() to serialize concurrent connect attempts
  • Fixing the sk_type != SOCK_SEQPACKET check to actually return the error instead of just assigning it
  • Adding a state re-check in sco_connect() after lock_sock() to catch state changes during the window between the locks
  • Adding sco_pi(sk)->conn check in sco_chan_add() to prevent double-attach of a socket to multiple connections
  • Adding hci_conn_drop() on sco_chan_add failure to prevent HCI connection leaks
Database specific 
{
    "cna_assigner":  "Linux",
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43023.json"
}
References

Affected packages

Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Affected ranges

Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
70a13b1e25fef37c87c8a1228ddb8900efbca7cf
Fixed
dabf22269242e2f2bf44c43fcdc2fa763df7f9cc
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
9a8ec9e8ebb5a7c0cfbce2d6b4a6b67b2b78e8f3
Fixed
adb90cd0f9f7a8d438fcb93354040fbafc5ae2a0
Fixed
7e296ffdab5bdab718dff7c14288fdcb9154fa27
Fixed
98c8d3bfdaa657d8f472dbbebd7ea8cd816d8a8d
Fixed
d002bd11024bd231bcb606877e33951ffb7bed14
Fixed
8a5b0135d4a5d9683203a3d9a12a711ccec5936b

Affected versions

v6.*
v6.1.109
v6.1.110
v6.1.111
v6.1.112
v6.1.113
v6.1.114
v6.1.115
v6.1.116
v6.1.117
v6.1.118
v6.1.119
v6.1.120
v6.1.121
v6.1.122
v6.1.123
v6.1.124
v6.1.125
v6.1.126
v6.1.127
v6.1.128
v6.1.129
v6.1.130
v6.1.131
v6.1.132
v6.1.133
v6.1.134
v6.1.135
v6.1.136
v6.1.137
v6.1.138
v6.1.139
v6.1.140
v6.1.141
v6.1.142
v6.1.143
v6.1.144
v6.1.145
v6.1.146
v6.1.147
v6.1.148
v6.1.149
v6.1.150
v6.1.151
v6.1.152
v6.1.153
v6.1.154
v6.1.155
v6.1.156
v6.1.157
v6.1.158
v6.1.159
v6.1.160
v6.1.161
v6.1.162
v6.1.163
v6.1.164
v6.1.165
v6.1.166
v6.1.167

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-43023.json"

Linux / Kernel

Package

Name
Kernel

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
6.1.168
Type
ECOSYSTEM
Events
Introduced
6.2.0
Fixed
6.6.134
Type
ECOSYSTEM
Events
Introduced
6.3.0
Fixed
6.12.81
Type
ECOSYSTEM
Events
Introduced
6.7.0
Fixed
6.18.22
Type
ECOSYSTEM
Events
Introduced
6.13.0
Fixed
6.19.12

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-43023.json"