The vulnerability CVE-2025-21997 in the Linux kernel arises from an integer overflow in the `xp_create_and_assign_umem()` function within the XDP (Express Data Path) socket implementation. This occurs when multiplying two 32-bit unsigned integers (i and pool->chunk_size), which can result in a 64-bit value wrapping around. Consequently, two different XDP buffers may erroneously reference the same memory region, leading to potential data corruption, privilege escalation, or denial of service.
Attackers exploiting this flaw could manipulate XDP socket configurations to trigger the overflow, causing memory access violations or unintended data sharing between network packets. The issue was discovered via static analysis (SVACE) and reported by InfoTeCS. Given the kernel-level impact, successful exploitation could compromise system stability and security.
DailyCVE Form:
Platform: Linux Kernel
Version: Pre-patch versions
Vulnerability: Integer Overflow
Severity: Critical
Date: 04/10/2025
What Undercode Say:
Exploitation:
1. Craft malicious XDP socket configurations.
2. Force `i pool->chunk_size` to overflow.
3. Trigger memory corruption via overlapping buffers.
Protection:
1. Apply kernel patches from official sources.
2. Validate `chunk_size` and loop bounds in `xp_create_and_assign_umem()`.
Analytics:
- Affects kernels with XDP socket support.
- Critical for high-performance networking systems.
Commands:
Check kernel version: uname -r Verify XDP module load: lsmod | grep xdp
Code Fix Example:
// Patch: Use u64 for multiplication u64 total_size = (u64)i (u64)pool->chunk_size; if (total_size > UINT_MAX) return -EINVAL;
Mitigation Script:
Temporary workaround (disable XDP): sudo rmmod xdp_sock
Debugging:
Monitor XDP errors: dmesg | grep xdp
Impact Assessment:
- CVSS:4.0 AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
- Requires local access but critical in shared environments.
References:
- Kernel Git commit: [patch-link]
- CVE details: [nvd.nist.gov/vuln/detail/CVE-2025-21997]
References:
Reported By: https://nvd.nist.gov/vuln/detail/CVE-2025-21997
Extra Source Hub:
Undercode
