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TI-2021-22013 Aliases CVE-2021-47356GHSA-74qf-46c3-qxv8

mISDN: fix possible use-after-free in HFC_cleanup()

Priority LOW 33CWE-416Published · Updated

Key facts

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

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

Summary

In the Linux kernel, the following vulnerability has been resolved: mISDN: fix possible use-after-free in HFC_cleanup() This module's remove path calls del_timer(). However, that function does not wait until the timer handler finishes. This means that the timer handler may still be running after the driver's remove function has finished, which would result in a use-after-free. Fix by calling del_timer_sync(), which makes sure the timer handler has finished, and unable to re-schedule itself.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00267 18th percentileScored 2026-11-07
Fix Partial Linux (Linux): 4.4.276, 4.9.276, 4.14.240 +6Red Hat: 4 advisoriesRed Hat: 9 fixed, 2 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
LinuxLinux2.6.29 and later4.4.276, 4.9.276, 4.14.240, 4.19.198, 5.4.133, 5.10.51, 5.12.18, 5.13.3, 5.14Patch availableCNA
  • Linux VendorLinux Affected 2.6.29 and later Fixed in 4.4.276, 4.9.276, 4.14.240, 4.19.198, 5.4.133, 5.10.51, 5.12.18, 5.13.3, 5.14 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*before 4.4.276; 4.5 to before 4.9.276; 4.10 to before 4.14.240; 4.15 to before 4.19.198; 4.20 to before 5.4.133; 5.5 to before 5.10.51; 5.11 to before 5.12.18; 5.13 to before 5.13.3VulnerableLinux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions before 4.4.276; 4.5 to before 4.9.276; 4.10 to before 4.14.240; 4.15 to before 4.19.198; 4.20 to before 5.4.133; 5.5 to before 5.10.51; 5.11 to before 5.12.18; 5.13 to before 5.13.3 Vulnerable ·Linux

Remediation

  • Fix · CNA Linux (Linux) Fixed in 4.4.276, 4.9.276, 4.14.240, 4.19.198, 5.4.133, 5.10.51, 5.12.18, 5.13.3, 5.14

Red Hat 4 advisories

  • RHSA-2024:6993 Released 2024-09-24 · Red Hat rating Important
    kernel security update
    • Red Hat CodeReady Linux Builder EUS (v.8.8) kernel-tools-libs-devel-4.18.0-477.74.1.el8_8
    • Red Hat Enterprise Linux BaseOS EUS (v.8.8) bpftool-4.18.0-477.74.1.el8_8, kernel-4.18.0-477.74.1.el8_8, kernel-abi-stablelists-4.18.0-477.74.1.el8_8 +19
  • RHSA-2024:5692 Released 2024-08-21 · Red Hat rating Moderate
    kernel security update
    • Red Hat Enterprise Linux BaseOS AUS (v.8.6) bpftool-4.18.0-372.119.1.el8_6, kernel-4.18.0-372.119.1.el8_6, kernel-abi-stablelists-4.18.0-372.119.1.el8_6 +13
    • Red Hat Enterprise Linux BaseOS E4S (v.8.6) bpftool-4.18.0-372.119.1.el8_6, kernel-4.18.0-372.119.1.el8_6, kernel-abi-stablelists-4.18.0-372.119.1.el8_6 +18
    • Red Hat Enterprise Linux BaseOS TUS (v.8.6) bpftool-4.18.0-372.119.1.el8_6, kernel-4.18.0-372.119.1.el8_6, kernel-abi-stablelists-4.18.0-372.119.1.el8_6 +13
  • RHSA-2024:4352 Released 2024-07-08 · Red Hat rating Important
    kernel-rt security and bug fix update
    • Red Hat Enterprise Linux NFV (v. 8) kernel-rt-4.18.0-553.8.1.rt7.349.el8_10, kernel-rt-core-4.18.0-553.8.1.rt7.349.el8_10, kernel-rt-debug-4.18.0-553.8.1.rt7.349.el8_10 +9
    • Red Hat Enterprise Linux RT (v. 8) kernel-rt-4.18.0-553.8.1.rt7.349.el8_10, kernel-rt-core-4.18.0-553.8.1.rt7.349.el8_10, kernel-rt-debug-4.18.0-553.8.1.rt7.349.el8_10 +7
Show 1 more Red Hat advisories
  • RHSA-2024:4211 Released 2024-07-02 · Red Hat rating Important
    kernel security and bug fix update
    • Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-553.8.1.el8_10, kernel-4.18.0-553.8.1.el8_10, kernel-abi-stablelists-4.18.0-553.8.1.el8_10 +19
    • Red Hat Enterprise Linux CRB (v. 8) kernel-tools-libs-devel-4.18.0-553.8.1.el8_10

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 7AffectedNo fix planned: Out of support scope
Red Hat CodeReady Linux Builder EUS (v.8.8)Fixed RHSA-2024:6993
Red Hat Enterprise Linux BaseOS (v. 8)Fixed RHSA-2024:4211
Red Hat Enterprise Linux BaseOS AUS (v.8.6)Fixed RHSA-2024:5692
Red Hat Enterprise Linux BaseOS E4S (v.8.6)Fixed RHSA-2024:5692
Red Hat Enterprise Linux BaseOS EUS (v.8.8)Fixed RHSA-2024:6993
Red Hat Enterprise Linux BaseOS TUS (v.8.6)Fixed RHSA-2024:5692
Red Hat Enterprise Linux CRB (v. 8)Fixed RHSA-2024:4211
Red Hat Enterprise Linux NFV (v. 8)Fixed RHSA-2024:4352
Red Hat Enterprise Linux RT (v. 8)Fixed RHSA-2024:4352
Not affected: 5 products
  • Red Hat Enterprise Linux 9
  • Red Hat Enterprise Linux BaseOS (v. 8)
  • Red Hat Enterprise Linux BaseOS AUS (v.8.6)
  • Red Hat Enterprise Linux BaseOS E4S (v.8.6)
  • Red Hat Enterprise Linux BaseOS TUS (v.8.6)

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-47356
  2. 2026-10-03 Alias added: GHSA-74qf-46c3-qxv8

References

Patch 9

  • 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