Linux KernelOperating system · Linux

CVE-2025-38465

MEDIUM · 5.5 CVSS v3.1 Published 2025-07-25
Fix available
A fix is available. Upgrade to 5.4.296 / 5.10.240 or later.
See remediation →
57/100
Remediation priority · Elevated
Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
In the Linux kernel, the following vulnerability has been resolved: netlink: Fix wraparounds of sk->sk_rmem_alloc. Netlink has this pattern in some places if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf) atomic_add(skb->truesize, &sk->sk_rmem_alloc); , which has the same problem fixed by commit 5a465a0da13e ("udp: Fix multiple wraparounds of sk->sk_rmem_alloc."). For example, if we set INT_MAX to SO_RCVBUFFORCE, the condition is always false as the two operands are of int. Then, a single socket can eat as many skb as possible until OOM happens, and we can see multiple wraparounds of sk->sk_rmem_alloc. Let's fix it by using atomic_add_return() and comparing the two variables as unsigned int. Before: [root@fedora ~]# ss -f netlink Recv-Q Send-Q Local Address:Port Peer Address:Port -1668710080 0 rtnl:nl_wraparound/293 * After: [root@fedora ~]# ss -f netlink Recv-Q Send-Q Local Address:Port Peer Address:Port 2147483072 0 rtnl:nl_wraparound/290 * ^ `--- INT_MAX - 576

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-401

Allocated memory is never released on some path, so a long-running service or a repeatedly triggered request steadily consumes memory until performance degrades or the process crashes. Attackers exploit it by simply driving the leaking path. Remediation is pairing every allocation with a release and using ownership patterns or tooling to catch what leaks.

General guidance for the memory leak class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Linux KernelOperating system
Affected:>= 2.6.13, < 5.4.296>= 5.5, < 5.10.240>= 5.11, < 5.15.189>= 5.16, < 6.1.146>= 6.2, < 6.6.99>= 6.7, < 6.12.39>= 6.13, < 6.15.7= 2.6.12= 6.16
Debian LinuxOperating system
Affected:= 11.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 5.4.296 / 5.10.240 / 5.15.189 or later
Fixed in 5.4.2965.10.2405.15.189
Vendor patch git.kernel.org →
Recommended fix High confidence

Linux Kernel 5.4.296, 5.10.240, 5.15.189, or 6.1.146 or later; Debian 11.0 should upgrade to Debian 12 (Bookworm) for a supported kernel with this fix

  1. Identify the current kernel version using 'uname -r'
  2. Backup critical data and create a system snapshot or backup before upgrading
  3. For Debian 11.0, update package lists with 'apt update'
  4. Upgrade the kernel package using 'apt install linux-image-<version>' or 'apt upgrade linux-image-generic'
  5. For enterprise distributions, use vendor-specific package managers (e.g., 'dnf upgrade' for RHEL/Fedora, 'apt-get dist-upgrade' for Debian/Ubuntu)
  6. Reboot the system to load the new kernel using 'systemctl reboot' or 'shutdown -r now'
  7. Verify the new kernel version with 'uname -r' and confirm the fix is applied
  8. Check system logs for any boot or hardware detection issues
Caveat Kernel upgrades may cause compatibility issues with proprietary drivers (e.g., NVIDIA, VMware) or older software; proprietary kernel modules may need rebuilding; some system calls or behavior changes may affect legacy applications

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $1,600. Get the upgrade done

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-38465 in production — separate from our analysis above.

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What this is

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What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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