cbcvebase.
CVE-2025-40210
published 2025-11-21

CVE-2025-40210: 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…

PriorityP338high7.5CVSS 3.1
AVNACLPRNUINSUCNINAH
EPSS
0.33%
25.2th percentile
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.

Affected

10 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.17.8-1 (forky)linux 6.17.8-1 (forky)
linuxlinux
linuxlinux>= 48aab1606fa80027143a445224f552b4eeea845b < b3ee7ce432289deac87b9d14e01f2fe6958f7f0bb3ee7ce432289deac87b9d14e01f2fe6958f7f0b
linuxlinux>= 48aab1606fa80027143a445224f552b4eeea845b < 3e7f011c255582d7c914133785bbba19904417133e7f011c255582d7c914133785bbba1990441713
linuxlinux_kernel>= 0 < 6.17.8-16.17.8-1
linuxlinux_kernel>= 0 < 6.17.0-14.146.17.0-14.14
linuxlinux_kernel>= 6.17.0 < 6.17.86.17.8
msrcazl3_kernel_6.6.112.1-2_on_azure_linux_3.0
ubuntulinux-aws
ubuntulinux-oracle

CVSS provenance

nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
vendor_redhat7.5MEDIUM
vendor_msrc5.5MEDIUM
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