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.
CVSS Details
- CVSS 3.1 Base Score: 7.5
- CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Redhat_linux | — | Upgrade kernelNo solution existsUpgrade kernel-rt | May 20, 2026 | Nov 21, 2025 |
| Ubuntu | — | Upgrade linux-image-6.17.0-1007-awsUpgrade linux-image-6.17.0-14-genericUpgrade linux-image-raspi-6.17Upgrade linux-image-awsUpgrade linux-image-oracle-6.17Upgrade linux-image-oem-6.17Upgrade linux-image-realtimeUpgrade linux-image-gcp-6.17Upgrade linux-image-oracleUpgrade linux-image-gcp-64k-6.17Upgrade linux-image-oracle-64kUpgrade linux-image-6.17.0-1008-raspiUpgrade linux-image-realtime-6.17Upgrade linux-image-virtualUpgrade linux-image-aws-64kUpgrade linux-image-6.17.0-1007-gcp-64kUpgrade linux-image-gcp-64kUpgrade linux-image-virtual-6.17Upgrade linux-image-generic-6.17Upgrade linux-image-azureUpgrade linux-image-6.17.0-1007-aws-64kUpgrade linux-image-6.17.0-1007-oracleUpgrade linux-image-oracle-64k-6.17Upgrade linux-image-6.17.0-1007-oracle-64kUpgrade linux-image-6.17.0-1006-realtimeUpgrade linux-image-generic-64k-6.17Upgrade linux-image-generic-64kUpgrade linux-image-aws-6.17Upgrade linux-image-6.17.0-1007-gcpUpgrade linux-image-genericUpgrade linux-image-aws-64k-6.17Upgrade linux-image-6.17.0-14-generic-64kUpgrade linux-image-azure-6.17Upgrade linux-image-6.17.0-1008-azureUpgrade linux-image-raspiUpgrade linux-image-gcpUpgrade linux-image-6.17.0-1011-oem | Feb 13, 2026 | Feb 12, 2026 |
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