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TI-2026-18692 Aliases CVE-2026-23255GHSA-9w39-mw48-92gc

net: add proper RCU protection to /proc/net/ptype

Priority LOW 24Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
None · None · High
Fix status
Partial Red Hat: 4 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat.

Summary

In the Linux kernel, the following vulnerability has been resolved: net: add proper RCU protection to /proc/net/ptype Yin Fengwei reported an RCU stall in ptype_seq_show() and provided a patch. Real issue is that ptype_seq_next() and ptype_seq_show() violate RCU rules. ptype_seq_show() runs under rcu_read_lock(), and reads pt->dev to get device name without any barrier. At the same time, concurrent writers can remove a packet_type structure (which is correctly freed after an RCU grace period) and clear pt->dev without an RCU grace period. Define ptype_iter_state to carry a dev pointer along seq_net_private: struct ptype_iter_state { struct seq_net_private p; struct net_device *dev; // added in this patch }; We need to record the device pointer in ptype_get_idx() and ptype_seq_next() so that ptype_seq_show() is safe against concurrent pt->dev changes. We also need to add full RCU protection in ptype_seq_next(). (Missing READ_ONCE() when reading list.next values) Many thanks to Dong Chenchen for providing a repro.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00121 1st percentileScored 2026-11-07
Fix Partial Linux (Linux): 6.1.175, 6.6.136, 6.12.80 +2Red Hat: 4 without a fix

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

VendorProductAffected versionsFixed inStatusSource
LinuxLinux2.6.12 and later6.1.175, 6.6.136, 6.12.80, 6.18.10, 6.19Patch availableCNA
  • Linux VendorLinux Affected 2.6.12 and later Fixed in 6.1.175, 6.6.136, 6.12.80, 6.18.10, 6.19 Patch available CNA

CPE configurations NVD · 14

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*2.6.12.1 to before 6.6.136; 6.7 to before 6.12.80; 6.13 to before 6.18.10VulnerableLinux
cpe:2.3:o:linux:linux_kernel:2.6.12:-:*:*:*:*:*:*2.6.12VulnerableLinux
cpe:2.3:o:linux:linux_kernel:2.6.12:rc2:*:*:*:*:*:*2.6.12 rc2VulnerableLinux
cpe:2.3:o:linux:linux_kernel:2.6.12:rc3:*:*:*:*:*:*2.6.12 rc3VulnerableLinux
cpe:2.3:o:linux:linux_kernel:2.6.12:rc4:*:*:*:*:*:*2.6.12 rc4VulnerableLinux
cpe:2.3:o:linux:linux_kernel:2.6.12:rc5:*:*:*:*:*:*2.6.12 rc5VulnerableLinux
cpe:2.3:o:linux:linux_kernel:6.19:rc1:*:*:*:*:*:*6.19 rc1VulnerableLinux
cpe:2.3:o:linux:linux_kernel:6.19:rc2:*:*:*:*:*:*6.19 rc2VulnerableLinux
cpe:2.3:o:linux:linux_kernel:6.19:rc3:*:*:*:*:*:*6.19 rc3VulnerableLinux
cpe:2.3:o:linux:linux_kernel:6.19:rc4:*:*:*:*:*:*6.19 rc4VulnerableLinux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 2.6.12.1 to before 6.6.136; 6.7 to before 6.12.80; 6.13 to before 6.18.10 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:2.6.12:-:*:*:*:*:*:* Versions 2.6.12 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:2.6.12:rc2:*:*:*:*:*:* Versions 2.6.12 rc2 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:2.6.12:rc3:*:*:*:*:*:* Versions 2.6.12 rc3 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:2.6.12:rc4:*:*:*:*:*:* Versions 2.6.12 rc4 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:2.6.12:rc5:*:*:*:*:*:* Versions 2.6.12 rc5 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:6.19:rc1:*:*:*:*:*:* Versions 6.19 rc1 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:6.19:rc2:*:*:*:*:*:* Versions 6.19 rc2 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:6.19:rc3:*:*:*:*:*:* Versions 6.19 rc3 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:6.19:rc4:*:*:*:*:*:* Versions 6.19 rc4 Vulnerable ·Linux
Show 4 more CPE
CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:6.19:rc5:*:*:*:*:*:*6.19 rc5VulnerableLinux
cpe:2.3:o:linux:linux_kernel:6.19:rc6:*:*:*:*:*:*6.19 rc6VulnerableLinux
cpe:2.3:o:linux:linux_kernel:6.19:rc7:*:*:*:*:*:*6.19 rc7VulnerableLinux
cpe:2.3:o:linux:linux_kernel:6.19:rc8:*:*:*:*:*:*6.19 rc8VulnerableLinux
  • cpe:2.3:o:linux:linux_kernel:6.19:rc5:*:*:*:*:*:* Versions 6.19 rc5 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:6.19:rc6:*:*:*:*:*:* Versions 6.19 rc6 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:6.19:rc7:*:*:*:*:*:* Versions 6.19 rc7 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:6.19:rc8:*:*:*:*:*:* Versions 6.19 rc8 Vulnerable ·Linux

Remediation

  • Fix · CNA Linux (Linux) Fixed in 6.1.175, 6.6.136, 6.12.80, 6.18.10, 6.19

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: Fix deferred
Red Hat Enterprise Linux 7AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 8AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 9AffectedNo fix yet: Fix deferred
Not affected: 1 product
  • Red Hat Enterprise Linux 6

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-23255
  2. 2026-10-03 Alias added: GHSA-9w39-mw48-92gc
  3. 2026-11-05 CISA SSVC decision points changed

References

Patch 4

Other 1

  • 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
See all 15278 →

Sources

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