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TI-2025-25148 Aliases CVE-2025-37797GHSA-hvr4-ppmm-c7fp

net_sched: hfsc: Fix a UAF vulnerability in class handling

Priority LOW 35CWE-416Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 38 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_sched: hfsc: Fix a UAF vulnerability in class handling This patch fixes a Use-After-Free vulnerability in the HFSC qdisc class handling. The issue occurs due to a time-of-check/time-of-use condition in hfsc_change_class() when working with certain child qdiscs like netem or codel. The vulnerability works as follows: 1. hfsc_change_class() checks if a class has packets (q.qlen != 0) 2. It then calls qdisc_peek_len(), which for certain qdiscs (e.g., codel, netem) might drop packets and empty the queue 3. The code continues assuming the queue is still non-empty, adding the class to vttree 4. This breaks HFSC scheduler assumptions that only non-empty classes are in vttree 5. Later, when the class is destroyed, this can lead to a Use-After-Free The fix adds a second queue length check after qdisc_peek_len() to verify the queue wasn't emptied.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00225 13th percentileScored 2026-11-07
Fix Partial Linux (Linux): 5.4.293, 5.10.237, 5.15.181 +5Red Hat: 15 advisoriesRed Hat: 38 fixed, 2 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
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
LinuxLinux4.14 and later5.4.293, 5.10.237, 5.15.181, 6.1.136, 6.6.89, 6.12.26, 6.14.5, 6.15Patch availableCNA
  • Linux VendorLinux Affected 4.14 and later Fixed in 5.4.293, 5.10.237, 5.15.181, 6.1.136, 6.6.89, 6.12.26, 6.14.5, 6.15 Patch available CNA

CPE configurations NVD · 13

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*4.14.1 to before 5.4.293; 5.5 to before 5.10.237; 5.11 to before 5.15.181; 5.16 to before 6.1.136; 6.2 to before 6.6.89; 6.7 to before 6.12.26; 6.13 to before 6.14.5VulnerableLinux
cpe:2.3:o:linux:linux_kernel:4.14:-:*:*:*:*:*:*4.14VulnerableLinux
cpe:2.3:o:linux:linux_kernel:4.14:rc2:*:*:*:*:*:*4.14 rc2VulnerableLinux
cpe:2.3:o:linux:linux_kernel:4.14:rc3:*:*:*:*:*:*4.14 rc3VulnerableLinux
cpe:2.3:o:linux:linux_kernel:4.14:rc4:*:*:*:*:*:*4.14 rc4VulnerableLinux
cpe:2.3:o:linux:linux_kernel:4.14:rc5:*:*:*:*:*:*4.14 rc5VulnerableLinux
cpe:2.3:o:linux:linux_kernel:4.14:rc6:*:*:*:*:*:*4.14 rc6VulnerableLinux
cpe:2.3:o:linux:linux_kernel:4.14:rc7:*:*:*:*:*:*4.14 rc7VulnerableLinux
cpe:2.3:o:linux:linux_kernel:4.14:rc8:*:*:*:*:*:*4.14 rc8VulnerableLinux
cpe:2.3:o:linux:linux_kernel:6.15:rc1:*:*:*:*:*:*6.15 rc1VulnerableLinux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 4.14.1 to before 5.4.293; 5.5 to before 5.10.237; 5.11 to before 5.15.181; 5.16 to before 6.1.136; 6.2 to before 6.6.89; 6.7 to before 6.12.26; 6.13 to before 6.14.5 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:4.14:-:*:*:*:*:*:* Versions 4.14 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:4.14:rc2:*:*:*:*:*:* Versions 4.14 rc2 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:4.14:rc3:*:*:*:*:*:* Versions 4.14 rc3 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:4.14:rc4:*:*:*:*:*:* Versions 4.14 rc4 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:4.14:rc5:*:*:*:*:*:* Versions 4.14 rc5 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:4.14:rc6:*:*:*:*:*:* Versions 4.14 rc6 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:4.14:rc7:*:*:*:*:*:* Versions 4.14 rc7 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:4.14:rc8:*:*:*:*:*:* Versions 4.14 rc8 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:6.15:rc1:*:*:*:*:*:* Versions 6.15 rc1 Vulnerable ·Linux
Show 3 more CPE
CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:6.15:rc2:*:*:*:*:*:*6.15 rc2VulnerableLinux
cpe:2.3:o:linux:linux_kernel:6.15:rc3:*:*:*:*:*:*6.15 rc3VulnerableLinux
cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*11.0VulnerableDebian
  • cpe:2.3:o:linux:linux_kernel:6.15:rc2:*:*:*:*:*:* Versions 6.15 rc2 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:6.15:rc3:*:*:*:*:*:* Versions 6.15 rc3 Vulnerable ·Linux
  • cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* Versions 11.0 Vulnerable ·Debian

Remediation

  • Fix · CNA Linux (Linux) Fixed in 5.4.293, 5.10.237, 5.15.181, 6.1.136, 6.6.89, 6.12.26, 6.14.5, 6.15

Red Hat 15 advisories

  • RHSA-2025:22752 Released 2025-12-04 · Red Hat rating Moderate
    kernel security update
    • Red Hat Enterprise Linux BaseOS AUS (v.8.4) bpftool-4.18.0-305.179.1.el8_4, kernel-4.18.0-305.179.1.el8_4, kernel-abi-stablelists-4.18.0-305.179.1.el8_4 +14
    • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4) bpftool-4.18.0-305.179.1.el8_4, kernel-4.18.0-305.179.1.el8_4, kernel-abi-stablelists-4.18.0-305.179.1.el8_4 +14
  • RHSA-2025:21667 Released 2025-11-18 · Red Hat rating Moderate
    kernel security update
    • Red Hat Enterprise Linux BaseOS AUS (v. 8.2) bpftool-4.18.0-193.173.1.el8_2, kernel-4.18.0-193.173.1.el8_2, kernel-abi-whitelists-4.18.0-193.173.1.el8_2 +14
  • RHSA-2025:21082 Released 2025-11-12 · Red Hat rating Moderate
    kernel-rt security update
    • Red Hat Enterprise Linux for Real Time (v. 7 ELS) kernel-rt-3.10.0-1160.142.1.rt56.1294.el7, kernel-rt-debug-3.10.0-1160.142.1.rt56.1294.el7, kernel-rt-debug-devel-3.10.0-1160.142.1.rt56.1294.el7 +4
Show 12 more Red Hat advisories
  • RHSA-2025:21063 Released 2025-11-12 · Red Hat rating Moderate
    kernel security update
    • Red Hat Enterprise Linux Server (v. 7 ELS) bpftool-3.10.0-1160.142.1.el7, kernel-3.10.0-1160.142.1.el7, kernel-abi-whitelists-3.10.0-1160.142.1.el7 +11
    • Red Hat Enterprise Linux Server Optional (v. 7 ELS) kernel-debug-devel-3.10.0-1160.142.1.el7, kernel-tools-libs-devel-3.10.0-1160.142.1.el7
  • RHSA-2025:19222 Released 2025-10-29 · Red Hat rating Moderate
    kernel security update
    • Red Hat Enterprise Linux BaseOS AUS (v.8.6) bpftool-4.18.0-372.166.1.el8_6, kernel-4.18.0-372.166.1.el8_6, kernel-abi-stablelists-4.18.0-372.166.1.el8_6 +14
    • Red Hat Enterprise Linux BaseOS E4S (v.8.6) bpftool-4.18.0-372.166.1.el8_6, kernel-4.18.0-372.166.1.el8_6, kernel-abi-stablelists-4.18.0-372.166.1.el8_6 +19
    • Red Hat Enterprise Linux BaseOS TUS (v.8.6) bpftool-4.18.0-372.166.1.el8_6, kernel-4.18.0-372.166.1.el8_6, kernel-abi-stablelists-4.18.0-372.166.1.el8_6 +14
  • RHSA-2025:18932 Released 2025-10-22 · Red Hat rating Moderate
    kernel security update
    • Red Hat Enterprise Linux BaseOS E4S (v.8.8) bpftool-4.18.0-477.116.1.el8_8, kernel-4.18.0-477.116.1.el8_8, kernel-abi-stablelists-4.18.0-477.116.1.el8_8 +14
    • Red Hat Enterprise Linux BaseOS TUS (v.8.8) bpftool-4.18.0-477.116.1.el8_8, kernel-4.18.0-477.116.1.el8_8, kernel-abi-stablelists-4.18.0-477.116.1.el8_8 +14
  • RHSA-2025:16919 Released 2025-09-29 · Red Hat rating Moderate
    kernel security update
    • Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-553.77.1.el8_10, kernel-4.18.0-553.77.1.el8_10, kernel-abi-stablelists-4.18.0-553.77.1.el8_10 +19
    • Red Hat Enterprise Linux CRB (v. 8) kernel-tools-libs-devel-4.18.0-553.77.1.el8_10
  • RHSA-2025:16920 Released 2025-09-29 · Red Hat rating Moderate
    kernel-rt security update
    • Red Hat Enterprise Linux NFV (v. 8) kernel-rt-4.18.0-553.77.1.rt7.418.el8_10, kernel-rt-core-4.18.0-553.77.1.rt7.418.el8_10, kernel-rt-debug-4.18.0-553.77.1.rt7.418.el8_10 +9
    • Red Hat Enterprise Linux RT (v. 8) kernel-rt-4.18.0-553.77.1.rt7.418.el8_10, kernel-rt-core-4.18.0-553.77.1.rt7.418.el8_10, kernel-rt-debug-4.18.0-553.77.1.rt7.418.el8_10 +7
  • RHSA-2025:14094 Released 2025-08-19 · Red Hat rating Moderate
    kernel-rt security update
    • Red Hat Enterprise Linux NFV E4S (v.9.0) kernel-rt-5.14.0-70.142.1.rt21.214.el9_0, kernel-rt-core-5.14.0-70.142.1.rt21.214.el9_0, kernel-rt-debug-5.14.0-70.142.1.rt21.214.el9_0 +9
    • Red Hat Enterprise Linux Real Time E4S (v.9.0) kernel-rt-5.14.0-70.142.1.rt21.214.el9_0, kernel-rt-core-5.14.0-70.142.1.rt21.214.el9_0, kernel-rt-debug-5.14.0-70.142.1.rt21.214.el9_0 +7
  • RHSA-2025:14054 Released 2025-08-19 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.0) kernel-debug-devel-5.14.0-70.142.1.el9_0, kernel-debug-devel-matched-5.14.0-70.142.1.el9_0, kernel-devel-5.14.0-70.142.1.el9_0 +5
    • Red Hat Enterprise Linux BaseOS E4S (v.9.0) bpftool-5.14.0-70.142.1.el9_0, kernel-5.14.0-70.142.1.el9_0, kernel-abi-stablelists-5.14.0-70.142.1.el9_0 +14
  • RHSA-2025:13946 Released 2025-08-18 · Red Hat rating Moderate
    kernel security update
    • Red Hat CodeReady Linux Builder EUS (v.9.4) kernel-tools-libs-devel-5.14.0-427.83.1.el9_4, libperf-5.14.0-427.83.1.el9_4
    • Red Hat Enterprise Linux AppStream EUS (v.9.4) kernel-64k-debug-devel-5.14.0-427.83.1.el9_4, kernel-64k-debug-devel-matched-5.14.0-427.83.1.el9_4, kernel-64k-devel-5.14.0-427.83.1.el9_4 +11
    • Red Hat Enterprise Linux BaseOS EUS (v.9.4) bpftool-7.3.0-427.83.1.el9_4, kernel-5.14.0-427.83.1.el9_4, kernel-64k-5.14.0-427.83.1.el9_4 +29
    • Red Hat Enterprise Linux Real Time EUS (v.9.4) kernel-rt-5.14.0-427.83.1.el9_4, kernel-rt-core-5.14.0-427.83.1.el9_4, kernel-rt-debug-5.14.0-427.83.1.el9_4 +9
    • Red Hat Enterprise Linux Real Time for NFV EUS (v.9.4) kernel-rt-5.14.0-427.83.1.el9_4, kernel-rt-core-5.14.0-427.83.1.el9_4, kernel-rt-debug-5.14.0-427.83.1.el9_4 +11
  • RHSA-2025:13781 Released 2025-08-13 · Red Hat rating Moderate
    kernel security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.2) kernel-64k-debug-devel-5.14.0-284.130.1.el9_2, kernel-64k-debug-devel-matched-5.14.0-284.130.1.el9_2, kernel-64k-devel-5.14.0-284.130.1.el9_2 +10
    • Red Hat Enterprise Linux BaseOS E4S (v.9.2) bpftool-7.0.0-284.130.1.el9_2, kernel-5.14.0-284.130.1.el9_2, kernel-64k-5.14.0-284.130.1.el9_2 +29
  • RHSA-2025:13633 Released 2025-08-11 · Red Hat rating Moderate
    kernel-rt security update
    • Red Hat Enterprise Linux Real Time E4S (v.9.2) kernel-rt-5.14.0-284.130.1.rt14.415.el9_2, kernel-rt-core-5.14.0-284.130.1.rt14.415.el9_2, kernel-rt-debug-5.14.0-284.130.1.rt14.415.el9_2 +9
    • Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2) kernel-rt-5.14.0-284.130.1.rt14.415.el9_2, kernel-rt-core-5.14.0-284.130.1.rt14.415.el9_2, kernel-rt-debug-5.14.0-284.130.1.rt14.415.el9_2 +11
  • RHSA-2025:11861 Released 2025-07-28 · Red Hat rating Moderate
    kernel security update
    • Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-570.30.1.el9_6, kernel-64k-debug-devel-matched-5.14.0-570.30.1.el9_6, kernel-64k-devel-5.14.0-570.30.1.el9_6 +12
    • Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-570.30.1.el9_6, kernel-64k-5.14.0-570.30.1.el9_6, kernel-64k-core-5.14.0-570.30.1.el9_6 +28
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-570.30.1.el9_6, libperf-5.14.0-570.30.1.el9_6
    • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-570.30.1.el9_6, kernel-rt-64k-5.14.0-570.30.1.el9_6, kernel-rt-64k-core-5.14.0-570.30.1.el9_6 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-570.30.1.el9_6, kernel-rt-core-5.14.0-570.30.1.el9_6, kernel-rt-debug-5.14.0-570.30.1.el9_6 +11
  • RHSA-2025:11855 Released 2025-07-28 · Red Hat rating Moderate
    kernel security update
    • Red Hat Enterprise Linux AppStream (v. 10) kernel-64k-debug-devel-6.12.0-55.24.1.el10_0, kernel-64k-debug-devel-matched-6.12.0-55.24.1.el10_0, kernel-64k-devel-6.12.0-55.24.1.el10_0 +12
    • Red Hat Enterprise Linux BaseOS (v. 10) kernel-6.12.0-55.24.1.el10_0, kernel-64k-6.12.0-55.24.1.el10_0, kernel-64k-core-6.12.0-55.24.1.el10_0 +28
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) kernel-tools-libs-devel-6.12.0-55.24.1.el10_0, libperf-6.12.0-55.24.1.el10_0
    • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt-6.12.0-55.24.1.el10_0, kernel-rt-64k-6.12.0-55.24.1.el10_0, kernel-rt-64k-core-6.12.0-55.24.1.el10_0 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt-6.12.0-55.24.1.el10_0, kernel-rt-core-6.12.0-55.24.1.el10_0, kernel-rt-debug-6.12.0-55.24.1.el10_0 +11

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 9AffectedNo fix yet
Red Hat CodeReady Linux Builder EUS (v.9.4)Fixed RHSA-2025:13946
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2025:11855
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2025:11861
Red Hat Enterprise Linux AppStream E4S (v.9.0)Fixed RHSA-2025:14054
Red Hat Enterprise Linux AppStream E4S (v.9.2)Fixed RHSA-2025:13781
Red Hat Enterprise Linux AppStream EUS (v.9.4)Fixed RHSA-2025:13946
Red Hat Enterprise Linux BaseOS (v. 10)Fixed RHSA-2025:11855
Red Hat Enterprise Linux BaseOS (v. 8)Fixed RHSA-2025:16919
Red Hat Enterprise Linux BaseOS (v. 9)Fixed RHSA-2025:11861
Red Hat Enterprise Linux BaseOS AUS (v. 8.2)Fixed RHSA-2025:21667
Red Hat Enterprise Linux BaseOS AUS (v.8.4)Fixed RHSA-2025:22752
Red Hat Enterprise Linux BaseOS AUS (v.8.6)Fixed RHSA-2025:19222
Red Hat Enterprise Linux BaseOS E4S (v.8.6)Fixed RHSA-2025:19222
Red Hat Enterprise Linux BaseOS E4S (v.8.8)Fixed RHSA-2025:18932
Red Hat Enterprise Linux BaseOS E4S (v.9.0)Fixed RHSA-2025:14054
Red Hat Enterprise Linux BaseOS E4S (v.9.2)Fixed RHSA-2025:13781
Red Hat Enterprise Linux BaseOS EUS (v.9.4)Fixed RHSA-2025:13946
Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4)Fixed RHSA-2025:22752
Red Hat Enterprise Linux BaseOS TUS (v.8.6)Fixed RHSA-2025:19222
Red Hat Enterprise Linux BaseOS TUS (v.8.8)Fixed RHSA-2025:18932
Red Hat Enterprise Linux CRB (v. 8)Fixed RHSA-2025:16919
Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)Fixed RHSA-2025:11855
Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)Fixed RHSA-2025:11861
Red Hat Enterprise Linux NFV (v. 8)Fixed RHSA-2025:16920
Red Hat Enterprise Linux NFV E4S (v.9.0)Fixed RHSA-2025:14094
Red Hat Enterprise Linux RT (v. 8)Fixed RHSA-2025:16920
Red Hat Enterprise Linux Real Time (v. 10)Fixed RHSA-2025:11855
Red Hat Enterprise Linux Real Time (v. 9)Fixed RHSA-2025:11861
Red Hat Enterprise Linux Real Time E4S (v.9.0)Fixed RHSA-2025:14094
Red Hat Enterprise Linux Real Time E4S (v.9.2)Fixed RHSA-2025:13633
Red Hat Enterprise Linux Real Time EUS (v.9.4)Fixed RHSA-2025:13946
Red Hat Enterprise Linux Real Time for NFV (v. 10)Fixed RHSA-2025:11855
Red Hat Enterprise Linux Real Time for NFV (v. 9)Fixed RHSA-2025:11861
Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2)Fixed RHSA-2025:13633
Red Hat Enterprise Linux Real Time for NFV EUS (v.9.4)Fixed RHSA-2025:13946
Red Hat Enterprise Linux Server (v. 7 ELS)Fixed RHSA-2025:21063
Red Hat Enterprise Linux Server Optional (v. 7 ELS)Fixed RHSA-2025:21063
Red Hat Enterprise Linux for Real Time (v. 7 ELS)Fixed RHSA-2025:21082

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-37797
  2. 2026-10-03 Alias added: GHSA-hvr4-ppmm-c7fp

References

Patch 8

Advisory 2

  • 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