CVE-2025-21648: netfilter: conntrack: clamp maximum hashtable size to INT_MAX
In the Linux kernel, the following vulnerability has been resolved:
netfilter: conntrack: clamp maximum hashtable size to INTMAX
Use INTMAX as maximum size for the conntrack hashtable. Otherwise, it is possible to hit WARNONONCE in kvmallocnodenoprof() when resizing hashtable because GFPNOWARN is unset. See:
0708a0afe291 ("mm: Consider GFPNOWARN flag for oversized kvmalloc() calls")
Note: hashtable resize is only possible from initnetns.
Other sources
This CVE was automatically created from a reference found in an email or other text. If you are reading this, then this CVE entry is probably erroneous, since this text should be replaced by the official CVE description automatically.
— Launchpad
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 5.10.234-1Fixed in 6.1.129-1Fixed in 6.1.135-1Fixed in 6.12.27-1 - Upgrade
Upgrade
debian/linux-6.1to a version that resolves this vulnerability.Fixed in 6.1.129-1~deb11u1
Event History
Frequently Asked Questions
What is the severity of CVE-2025-21648?
The severity of CVE-2025-21648 is classified as moderate.
How do I fix CVE-2025-21648?
To fix CVE-2025-21648, update your Linux kernel to the latest stable version that contains the patch addressing this vulnerability.
Who is affected by CVE-2025-21648?
CVE-2025-21648 affects users of the Linux kernel who utilize the conntrack module.
What impact does CVE-2025-21648 have on systems?
CVE-2025-21648 can lead to potential memory allocation warnings and degrade system stability during hash table resizing.
Is CVE-2025-21648 exploitable remotely?
CVE-2025-21648 is not directly exploitable remotely but may affect systems processing network traffic that rely on conntrack.