Read the docs
TI-2026-46105 Aliases CVE-2026-64541GHSA-wjv3-3r54-x298

net/smc: fix UAF in smc_cdc_rx_handler() by pinning the socket

Priority MEDIUM 50CWE-416Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 9 fixed, 2 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-416 and the CVSS impact.

Summary

In the Linux kernel, the following vulnerability has been resolved: net/smc: fix UAF in smc_cdc_rx_handler() by pinning the socket smc_cdc_rx_handler() looks up the connection by token under the link group's conns_lock, drops the lock, and then dereferences conn and the smc_sock derived from it, ending in sock_hold(&smc->sk) inside smc_cdc_msg_recv(). No reference is held across the lock release. The only reference pinning the socket while the connection is discoverable in the link group is taken in smc_lgr_register_conn() (sock_hold) and dropped in __smc_lgr_unregister_conn() (sock_put), both under conns_lock. Once the handler drops conns_lock, a concurrent close() -> smc_release() -> smc_conn_free() -> smc_lgr_unregister_conn() can drop that reference and free the smc_sock, so the handler's later sock_hold() runs on freed memory: WARNING: lib/refcount.c:25 at refcount_warn_saturate Workqueue: rxe_wq do_work refcount_warn_saturate (lib/refcount.c:25) smc_cdc_msg_recv (net/smc/smc_cdc.c:430) smc_cdc_rx_handler (net/smc/smc_cdc.c:502) smc_wr_rx_tasklet_fn (net/smc/smc_wr.c:445) tasklet_action_common (kernel/softirq.c:938) handle_softirqs (kernel/softirq.c:622) Kernel panic - not syncing: panic_on_warn set Only SMC-R is affected. The SMC-D receive tasklet is stopped by tasklet_kill(&conn->rx_tsklet) in smc_conn_free() before the connection is unregistered, so it cannot run concurrently with the free. Take the socket reference while still holding conns_lock, so the registration reference can no longer be the last one, and drop it once the handler is done.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00565 47th percentileScored 2026-11-07
Fix Partial Linux (Linux): 5.10.261, 5.15.212, 6.1.178 +5Red Hat: 3 advisoriesRed Hat: 9 fixed, 2 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux4.18 and later5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.97, 6.18.40, 7.1.5, 7.2Patch availableCNA
  • Linux VendorLinux Affected 4.18 and later Fixed in 5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.97, 6.18.40, 7.1.5, 7.2 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*——Linux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions — — ·Linux

Remediation

  • Fix · CNA Linux (Linux) Fixed in 5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.97, 6.18.40, 7.1.5, 7.2

Red Hat 3 advisories

  • RHSA-2026:95370 Released 2026-11-05 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-687.66.1.el9_8, kernel-64k-debug-devel-matched-5.14.0-687.66.1.el9_8, kernel-64k-devel-5.14.0-687.66.1.el9_8 +12
    • Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-687.66.1.el9_8, kernel-64k-5.14.0-687.66.1.el9_8, kernel-64k-core-5.14.0-687.66.1.el9_8 +28
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-687.66.1.el9_8, libperf-5.14.0-687.66.1.el9_8
    • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-687.66.1.el9_8, kernel-rt-64k-5.14.0-687.66.1.el9_8, kernel-rt-64k-core-5.14.0-687.66.1.el9_8 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-687.66.1.el9_8, kernel-rt-core-5.14.0-687.66.1.el9_8, kernel-rt-debug-5.14.0-687.66.1.el9_8 +9
  • RHSA-2026:95212 Released 2026-11-04 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-553.184.1.el8_10, kernel-4.18.0-553.184.1.el8_10, kernel-abi-stablelists-4.18.0-553.184.1.el8_10 +19
    • Red Hat Enterprise Linux CRB (v. 8) kernel-tools-libs-devel-4.18.0-553.184.1.el8_10
  • RHSA-2026:95100 Released 2026-11-04 · Red Hat rating Important
    kernel-rt security, bug fix, and enhancement update
    • Red Hat Enterprise Linux NFV (v. 8) kernel-rt-4.18.0-553.184.1.rt7.525.el8_10, kernel-rt-core-4.18.0-553.184.1.rt7.525.el8_10, kernel-rt-debug-4.18.0-553.184.1.rt7.525.el8_10 +9
    • Red Hat Enterprise Linux RT (v. 8) kernel-rt-4.18.0-553.184.1.rt7.525.el8_10, kernel-rt-core-4.18.0-553.184.1.rt7.525.el8_10, kernel-rt-debug-4.18.0-553.184.1.rt7.525.el8_10 +7

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 10AffectedNo fix yet
Red Hat Enterprise Linux 9AffectedNo fix yet
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:95370
Red Hat Enterprise Linux BaseOS (v. 8)Fixed RHSA-2026:95212
Red Hat Enterprise Linux BaseOS (v. 9)Fixed RHSA-2026:95370
Red Hat Enterprise Linux CRB (v. 8)Fixed RHSA-2026:95212
Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)Fixed RHSA-2026:95370
Red Hat Enterprise Linux NFV (v. 8)Fixed RHSA-2026:95100
Red Hat Enterprise Linux RT (v. 8)Fixed RHSA-2026:95100
Red Hat Enterprise Linux Real Time (v. 9)Fixed RHSA-2026:95370
Red Hat Enterprise Linux Real Time for NFV (v. 9)Fixed RHSA-2026:95370
Not affected: 2 products
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-64541
  2. 2026-10-03 Alias added: GHSA-wjv3-3r54-x298
  3. 2026-10-16 CISA SSVC decision points changed
  4. 2026-10-20 Weakness changed · CISA ADP
  5. 2026-10-31 CVSS score changed · Red Hat
  6. 2026-10-31 Affected versions changed · Red Hat
  7. 2026-11-04 Fix available: RHSA-2026:95212 · Red Hat
  8. 2026-11-04 Fix available: Red Hat Enterprise Linux BaseOS (v. 8), Red Hat Enterprise Linux CRB (v. 8) · Red Hat
  9. 2026-11-06 Fix available: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) +4 · Red Hat
  10. 2026-11-06 Fix available: RHSA-2026:95370 · Red Hat
  11. 2026-11-06 Fix available: RHSA-2026:95100 · Red Hat

References

Other 8

  • 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-2021-02452 Incorrect authorization in Ubuntu linux kernel 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
See all 21741 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences