Bluetooth: ISO: avoid NULL deref of conn in iso_conn_big_sync()
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 2 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-476.
Summary
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: ISO: avoid NULL deref of conn in iso_conn_big_sync() iso_conn_big_sync() drops the socket lock to call hci_get_route() and then re-acquires it, but dereferences iso_pi(sk)->conn->hcon afterwards without re-checking that conn is still valid. While the lock is dropped, the connection can be torn down under the same socket lock: iso_disconn_cfm() -> iso_conn_del() -> iso_chan_del() sets iso_pi(sk)->conn to NULL (and the broadcast teardown path can also clear conn->hcon on its own). When iso_conn_big_sync() re-acquires the lock and reads conn->hcon, conn may be NULL, causing a NULL pointer dereference (hcon is the first member of struct iso_conn). This path is reached from iso_sock_recvmsg() for a PA-sync broadcast sink socket (BT_SK_DEFER_SETUP | BT_SK_PA_SYNC), so the dropped-lock window can race with connection teardown driven by controller events. Re-validate iso_pi(sk)->conn and its hcon after re-acquiring the socket lock and bail out if the connection went away, as already done in the sibling iso_sock_rebind_bc().
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 6.12.6 to before 6.12.96 | 6.12.96 | Patch available | CNA |
| Linux | Linux | 6.13 and later | 6.12.96, 6.18.39, 7.1.4, 7.2 | Patch available | CNA |
- Linux VendorLinux Affected 6.12.6 to before 6.12.96 Fixed in 6.12.96 Patch available CNA
- Linux VendorLinux Affected 6.13 and later Fixed in 6.12.96, 6.18.39, 7.1.4, 7.2 Patch available CNA
CPE configurations NVD · 9
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 6.12.6 to before 6.12.96; 6.13.1 to before 6.18.39; 6.19 to before 7.1.4 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.13:-:*:*:*:*:*:* | 6.13 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.13:rc3:*:*:*:*:*:* | 6.13 rc3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.13:rc4:*:*:*:*:*:* | 6.13 rc4 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.13:rc5:*:*:*:*:*:* | 6.13 rc5 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.13:rc6:*:*:*:*:*:* | 6.13 rc6 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.13:rc7:*:*:*:*:*:* | 6.13 rc7 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.2:rc1:*:*:*:*:*:* | 7.2 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.2:rc2:*:*:*:*:*:* | 7.2 rc2 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 6.12.6 to before 6.12.96; 6.13.1 to before 6.18.39; 6.19 to before 7.1.4 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.13:-:*:*:*:*:*:* Versions 6.13 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.13:rc3:*:*:*:*:*:* Versions 6.13 rc3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.13:rc4:*:*:*:*:*:* Versions 6.13 rc4 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.13:rc5:*:*:*:*:*:* Versions 6.13 rc5 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.13:rc6:*:*:*:*:*:* Versions 6.13 rc6 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.13:rc7:*:*:*:*:*:* Versions 6.13 rc7 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.2:rc1:*:*:*:*:*:* Versions 7.2 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.2:rc2:*:*:*:*:*:* Versions 7.2 rc2 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 6.12.96
- Fix · CNA Linux (Linux) Fixed in 6.12.96, 6.18.39, 7.1.4, 7.2
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
Not affected: 4 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2026-64404
- 2026-10-03 Alias added: GHSA-f6gp-jxph-7wj2
- 2026-10-29 Affected versions changed · Red Hat
- 2026-11-06 CISA SSVC decision points changed
References
More Linux Kernel vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2026-64404 · CVE Program
- CVE-2026-64404 · NVD
- FIRST EPSS
- GHSA-f6gp-jxph-7wj2 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-64404 · Red Hat security data · CC BY 4.0
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