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TI-2026-46136 Aliases CVE-2026-64572GHSA-q235-77fh-m2c6

ipv4: fib: free fib_alias with kfree_rcu() on insert error path

Priority LOW 22Published · Updated

Key facts

Attack vector
—
Privileges required
—
User interaction
—
Attack complexity
—
Impact type
—
Confidentiality · integrity · availability
—
Fix status
Partial Red Hat: 16 fixed, 1 without a fix

No CVSS vector from any source. Fix status from CNA and Red Hat.

Summary

In the Linux kernel, the following vulnerability has been resolved: ipv4: fib: free fib_alias with kfree_rcu() on insert error path fib_table_insert() publishes new_fa into the leaf's fa_list with fib_insert_alias() before calling the fib entry notifiers. When a notifier fails, the error path removes new_fa with fib_remove_alias() (hlist_del_rcu) and frees it right away with kmem_cache_free(). fib_table_lookup() walks that list under rcu_read_lock() only, so a concurrent lookup that already reached new_fa keeps reading it after the free: BUG: KASAN: slab-use-after-free in fib_table_lookup (net/ipv4/fib_trie.c:1601) Read of size 1 at addr ffff88810676d4eb by task exploit/297 Call Trace: fib_table_lookup (net/ipv4/fib_trie.c:1601) ip_route_output_key_hash_rcu (net/ipv4/route.c:2814) ip_route_output_key_hash (net/ipv4/route.c:2705) __ip4_datagram_connect (net/ipv4/datagram.c:49) udp_connect (net/ipv4/udp.c:2144) __sys_connect (net/socket.c:2167) __x64_sys_connect (net/socket.c:2173) do_syscall_64 entry_SYSCALL_64_after_hwframe which belongs to the cache ip_fib_alias of size 56 Triggering the error path needs CAP_NET_ADMIN and a registered fib notifier that can reject a route; a netdevsim device whose IPv4 FIB resource is exhausted is enough. Free new_fa with alias_free_mem_rcu(), as fib_table_delete() already does for a fib_alias removed from the trie.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00201 10th percentileScored 2026-11-07
Fix Partial Linux (Linux): 5.10.265, 5.15.216, 6.1.183 +5Red Hat: 4 advisoriesRed Hat: 16 fixed, 1 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
LinuxLinux5.6 and later5.10.265, 5.15.216, 6.1.183, 6.6.148, 6.12.101, 6.18.42, 7.1.6, 7.2Patch availableCNA
  • Linux VendorLinux Affected 5.6 and later Fixed in 5.10.265, 5.15.216, 6.1.183, 6.6.148, 6.12.101, 6.18.42, 7.1.6, 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 5.10.265, 5.15.216, 6.1.183, 6.6.148, 6.12.101, 6.18.42, 7.1.6, 7.2

Red Hat 4 advisories

  • RHSA-2026:88477 Released 2026-10-23 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • 10Base-SMTV kernel-modules-internal-6.12.0-211.68.1.el10_2
    • Red Hat Enterprise Linux AppStream (v. 10) kernel-64k-debug-devel-6.12.0-211.68.1.el10_2, kernel-64k-debug-devel-matched-6.12.0-211.68.1.el10_2, kernel-64k-devel-6.12.0-211.68.1.el10_2 +12
    • Red Hat Enterprise Linux BaseOS (v. 10) kernel-6.12.0-211.68.1.el10_2, kernel-64k-6.12.0-211.68.1.el10_2, kernel-64k-core-6.12.0-211.68.1.el10_2 +29
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) kernel-tools-libs-devel-6.12.0-211.68.1.el10_2, libperf-6.12.0-211.68.1.el10_2
    • Red Hat Enterprise Linux Hidden (v. 10) kernel-modules-internal-6.12.0-211.68.1.el10_2
    • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt-6.12.0-211.68.1.el10_2, kernel-rt-64k-6.12.0-211.68.1.el10_2, kernel-rt-64k-core-6.12.0-211.68.1.el10_2 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt-6.12.0-211.68.1.el10_2, kernel-rt-core-6.12.0-211.68.1.el10_2, kernel-rt-debug-6.12.0-211.68.1.el10_2 +9
  • RHSA-2026:87375 Released 2026-10-21 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-553.177.1.el8_10, kernel-4.18.0-553.177.1.el8_10, kernel-abi-stablelists-4.18.0-553.177.1.el8_10 +19
    • Red Hat Enterprise Linux CRB (v. 8) kernel-tools-libs-devel-4.18.0-553.177.1.el8_10
  • RHSA-2026:87374 Released 2026-10-21 · Red Hat rating Important
    kernel-rt security update
    • Red Hat Enterprise Linux NFV (v. 8) kernel-rt-4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-core-4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-debug-4.18.0-553.177.1.rt7.518.el8_10 +9
    • Red Hat Enterprise Linux RT (v. 8) kernel-rt-4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-core-4.18.0-553.177.1.rt7.518.el8_10, kernel-rt-debug-4.18.0-553.177.1.rt7.518.el8_10 +7
Show 1 more Red Hat advisories
  • RHSA-2026:86033 Released 2026-10-20 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-687.59.1.el9_8, kernel-64k-debug-devel-matched-5.14.0-687.59.1.el9_8, kernel-64k-devel-5.14.0-687.59.1.el9_8 +12
    • Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-687.59.1.el9_8, kernel-64k-5.14.0-687.59.1.el9_8, kernel-64k-core-5.14.0-687.59.1.el9_8 +28
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-687.59.1.el9_8, libperf-5.14.0-687.59.1.el9_8
    • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-687.59.1.el9_8, kernel-rt-64k-5.14.0-687.59.1.el9_8, kernel-rt-64k-core-5.14.0-687.59.1.el9_8 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-687.59.1.el9_8, kernel-rt-core-5.14.0-687.59.1.el9_8, kernel-rt-debug-5.14.0-687.59.1.el9_8 +9

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat Enterprise Linux 9AffectedNo fix yet
10Base-SMTVFixed RHSA-2026:88477
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:88477
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:86033
Red Hat Enterprise Linux BaseOS (v. 10)Fixed RHSA-2026:88477
Red Hat Enterprise Linux BaseOS (v. 8)Fixed RHSA-2026:87375
Red Hat Enterprise Linux BaseOS (v. 9)Fixed RHSA-2026:86033
Red Hat Enterprise Linux CRB (v. 8)Fixed RHSA-2026:87375
Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)Fixed RHSA-2026:88477
Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)Fixed RHSA-2026:86033
Red Hat Enterprise Linux Hidden (v. 10)Fixed RHSA-2026:88477
Red Hat Enterprise Linux NFV (v. 8)Fixed RHSA-2026:87374
Red Hat Enterprise Linux RT (v. 8)Fixed RHSA-2026:87374
Red Hat Enterprise Linux Real Time (v. 10)Fixed RHSA-2026:88477
Red Hat Enterprise Linux Real Time (v. 9)Fixed RHSA-2026:86033
Red Hat Enterprise Linux Real Time for NFV (v. 10)Fixed RHSA-2026:88477
Red Hat Enterprise Linux Real Time for NFV (v. 9)Fixed RHSA-2026:86033
Not affected: 2 products
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-64572
  2. 2026-10-03 Alias added: GHSA-q235-77fh-m2c6
  3. 2026-10-21 Fix available: RHSA-2026:86033 · Red Hat
  4. 2026-10-21 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) +2 · Red Hat
  5. 2026-10-22 Fix available: RHSA-2026:87374 · Red Hat
  6. 2026-10-22 Fix available: RHSA-2026:87375 · Red Hat
  7. 2026-10-23 Fix available: RHSA-2026:88477 · Red Hat
  8. 2026-10-23 Fix available: 10Base-SMTV, Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10) +8 · Red Hat
  9. 2026-11-06 CISA SSVC decision points changed

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 21727 →

Sources

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