Cyber Resilience

CVE-2025-38020

Memory Safety in Linux Kernel 6.1 – 6.1.140

Published
18 June 2025
Modified
17 June 2026
Patch / advisory
CVSS Score v3.1 5.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0017 6th percentile
Risk Priority 41 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2025-38020 is a medium-severity NULL Pointer Dereference (CWE-476) vulnerability in Linux Linux Kernel. Its CVSS base score is 5.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Endpoint Denial of Service (T1499); ranked at the 6th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-15 (Development Process, Standards, and Tools) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Disable MACsec offload for uplink representor profile MACsec offload is not supported in switchdev mode for uplink representors. When switching to the uplink representor profile, the MACsec offload feature…

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must be cleared from the netdevice's features. If left enabled, attempts to add offloads result in a null pointer dereference, as the uplink representor does not support MACsec offload even though the feature bit remains set. Clear NETIF_F_HW_MACSEC in mlx5e_fix_uplink_rep_features(). Kernel log: Oops: general protection fault, probably for non-canonical address 0xdffffc000000000f: 0000 [#1] SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000078-0x000000000000007f] CPU: 29 UID: 0 PID: 4714 Comm: ip Not tainted 6.14.0-rc4_for_upstream_debug_2025_03_02_17_35 #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 RIP: 0010:__mutex_lock+0x128/0x1dd0 Code: d0 7c 08 84 d2 0f 85 ad 15 00 00 8b 35 91 5c fe 03 85 f6 75 29 49 8d 7e 60 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 a6 15 00 00 4d 3b 76 60 0f 85 fd 0b 00 00 65 ff RSP: 0018:ffff888147a4f160 EFLAGS: 00010206 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 000000000000000f RSI: 0000000000000000 RDI: 0000000000000078 RBP: ffff888147a4f2e0 R08: ffffffffa05d2c19 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 R13: dffffc0000000000 R14: 0000000000000018 R15: ffff888152de0000 FS: 00007f855e27d800(0000) GS:ffff88881ee80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000004e5768 CR3: 000000013ae7c005 CR4: 0000000000372eb0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400 Call Trace: <TASK> ? die_addr+0x3d/0xa0 ? exc_general_protection+0x144/0x220 ? asm_exc_general_protection+0x22/0x30 ? mlx5e_macsec_add_secy+0xf9/0x700 [mlx5_core] ? __mutex_lock+0x128/0x1dd0 ? lockdep_set_lock_cmp_fn+0x190/0x190 ? mlx5e_macsec_add_secy+0xf9/0x700 [mlx5_core] ? mutex_lock_io_nested+0x1ae0/0x1ae0 ? lock_acquire+0x1c2/0x530 ? macsec_upd_offload+0x145/0x380 ? lockdep_hardirqs_on_prepare+0x400/0x400 ? kasan_save_stack+0x30/0x40 ? kasan_save_stack+0x20/0x40 ? kasan_save_track+0x10/0x30 ? __kasan_kmalloc+0x77/0x90 ? __kmalloc_noprof+0x249/0x6b0 ? genl_family_rcv_msg_attrs_parse.constprop.0+0xb5/0x240 ? mlx5e_macsec_add_secy+0xf9/0x700 [mlx5_core] mlx5e_macsec_add_secy+0xf9/0x700 [mlx5_core] ? mlx5e_macsec_add_rxsa+0x11a0/0x11a0 [mlx5_core] macsec_update_offload+0x26c/0x820 ? macsec_set_mac_address+0x4b0/0x4b0 ? lockdep_hardirqs_on_prepare+0x284/0x400 ? _raw_spin_unlock_irqrestore+0x47/0x50 macsec_upd_offload+0x2c8/0x380 ? macsec_update_offload+0x820/0x820 ? __nla_parse+0x22/0x30 ? genl_family_rcv_msg_attrs_parse.constprop.0+0x15e/0x240 genl_family_rcv_msg_doit+0x1cc/0x2a0 ? genl_family_rcv_msg_attrs_parse.constprop.0+0x240/0x240 ? cap_capable+0xd4/0x330 genl_rcv_msg+0x3ea/0x670 ? genl_family_rcv_msg_dumpit+0x2a0/0x2a0 ? lockdep_set_lock_cmp_fn+0x190/0x190 ? macsec_update_offload+0x820/0x820 netlink_rcv_skb+0x12b/0x390 ? genl_family_rcv_msg_dumpit+0x2a0/0x2a0 ? netlink_ack+0xd80/0xd80 ? rwsem_down_read_slowpath+0xf90/0xf90 ? netlink_deliver_tap+0xcd/0xac0 ? netlink_deliver_tap+0x155/0xac0 ? _copy_from_iter+0x1bb/0x12c0 genl_rcv+0x24/0x40 netlink_unicast+0x440/0x700 ? netlink_attachskb+0x760/0x760 ? lock_acquire+0x1c2/0x530 ? __might_fault+0xbb/0x170 netlink_sendmsg+0x749/0xc10 ? netlink_unicast+0x700/0x700 ? __might_fault+0xbb/0x170 ? netlink_unicast+0x700/0x700 __sock_sendmsg+0xc5/0x190 ____sys_sendmsg+0x53f/0x760 ? import_iovec+0x7/0x10 ? kernel_sendmsg+0x30/0x30 ? __copy_msghdr+0x3c0/0x3c0 ? filter_irq_stacks+0x90/0x90 ? stack_depot_save_flags+0x28/0xa30 ___sys_sen ---truncated---

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
T1489 Service Stop Impact
Adversaries may stop or disable services on a system to render those services unavailable to legitimate users.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-38328Same product: Debian Debian Linux
CVE-2025-39675Same product: Debian Debian Linux
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CVE-2025-38362Same product: Debian Debian Linux
CVE-2025-38569Same product: Debian Debian Linux
CVE-2025-39676Same product: Debian Debian Linux
CVE-2024-26771Same product: Debian Debian Linux
CVE-2025-38167Same product: Debian Debian Linux
CVE-2025-38337Same product: Debian Debian Linux
CVE-2025-38147Same product: Debian Debian Linux

Affected Assets

linux
linux kernel
6.15 · 6.1 — 6.1.140 · 6.2 — 6.6.92 · 6.7 — 6.12.30
debian
debian linux
11.0

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation (including static analysis) directly finds null-dereference bugs before deployment.

Documented development standards and tools can enforce null-safety rules and safe pointer usage.

Engineering principles can mandate defensive coding such as explicit null checks before dereference.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices (static analysis, code review, safe coding standards) directly prevent NULL dereference bugs during development.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing can detect NULL dereference defects before release.

prevents

Secure SDLC mandates defensive coding practices that can prevent NULL dereferences.

prevents

Application security requirements can specify input validation and pointer-safety rules.

prevents

Secure architecture principles encourage defensive design that avoids unsafe pointer use.

prevents

Secure coding standards directly require NULL-pointer checks and safe dereference patterns.

References