Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: Revert "NFSD: Remove the cap on number of operations per NFSv4 COMPOUND" I've found that pynfs COMP6 now leaves the connection or lease in a strange state, which causes CLOSE9 to hang indefinitely. I've dug into it a little, but I haven't been able to root-cause it yet. However, I bisected to commit 48aab1606fa8 ("NFSD: Remove the cap on number of operations per NFSv4 COMPOUND"). Tianshuo Han also reports a potential vulnerability when decoding an NFSv4 COMPOUND. An attacker can place an arbitrarily large op count in the COMPOUND header, which results in: [ 51.410584] nfsd: vmalloc error: size 1209533382144, exceeds total pages, mode:0xdc0(GFP_KERNEL|__GFP_ZERO), nodemask=(null),cpuset=/,mems_allowed=0 when NFSD attempts to allocate the COMPOUND op array. Let's restore the operation-per-COMPOUND limit, but increased to 200 for now.
References
- https://git.kernel.org/stable/c/3e7f011c255582d7c914133785bbba1990441713
- https://git.kernel.org/stable/c/b3ee7ce432289deac87b9d14e01f2fe6958f7f0b
FAQ
What is CVE-2025-40210?
CVE-2025-40210 is a documented vulnerability. In the Linux kernel, the following vulnerability has been resolved: Revert "NFSD: Remove the cap on number of operations per NFSv4 COMPOUND" I've found that pynfs COMP6 now leaves the connection or ...
How severe is CVE-2025-40210?
CVSS scoring is not yet available for CVE-2025-40210. Check NVD for updates.
Is there a patch for CVE-2025-40210?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.